Electric space heater

Abstract

An electric space heater (1) comprises: a first electric heating arrangement (8) arranged to be powered by an alternating current power source (22) and a direct current power source (20); and a controller (24) arranged to control power distribution from the DC power source and the AC power source to the first heating arrangement.

Description

Technical Field

[0001] The present invention relates to electric space heaters. In particular, but not exclusively, the present invention relates to a self-contained electric space heater for heating a space on demand. Background Art

[0002] A space heater is a stand-alone heating device designed to heat a small area (or "space") rather than an entire building or large room. Space heaters can be used to supplement central heating or to provide heat to a small area that requires heating.

[0003] Space heaters that use electricity as a fuel source are known - they can be connected to mains AC power by plugging into an electrical outlet. Some space heaters have built-in thermostats that allow the user to set the desired temperature, and they may also have safety features such as automatic shutoff and tip-over protection.

[0004] Space heaters are often used for small rooms or spaces where heating with a central heating system is difficult or expensive, or where additional heat is temporarily needed. Space heaters can be an energy-efficient and cost-effective way to heat small areas, but they should be used with caution to avoid fire or other hazards. Electric space heaters work by using electricity (such as mains AC power) to power a heating element (such as a coil or metal block). When the heating element is energized, it heats up and begins transferring heat to the surrounding air or fluid (such as oil) or other objects.

[0005] There are many types of electric heaters, including:

[0006] 1. Convection Heaters: These heaters work by using electricity to power a heating element (such as a coil or metal block). When powered, the heating element heats up and begins transferring heat to the surrounding air or a fluid (such as oil) or other object, warming the surrounding air and creating a stream of warm air that circulates throughout the room. Heat is generated by the heating element's resistance to the flow of electricity. As electricity passes through the element, it encounters resistance, causing the element to heat up. In a convection heater, the heating element is typically located within a housing or enclosed space designed to allow air to circulate around it. As the air is heated by the element, it rises and is replaced by cooler air from the room, creating a stream of warm air that circulates throughout the space. This process helps to evenly distribute heat and raise the overall temperature of the room.

[0007] 2. Radiant Heaters: Radiant heaters work by using electricity to power a heating element (such as a coil or metal block). When the heating element is energized, it heats up and begins to transfer heat to surrounding objects and surfaces by emitting infrared radiation. Infrared radiation is a type of electromagnetic radiation with a wavelength longer than visible light and is invisible to the human eye. It can pass through the air and is absorbed by objects and surfaces it comes into contact with, raising their temperature. Heat is generated by the heating element's resistance to electric current. When electricity passes through the element, it encounters resistance, causing the element to heat up. In radiant heaters, the heating element is typically located within a housing or enclosure designed to allow infrared radiation to be emitted into the surrounding space. As the radiation is absorbed by objects and surfaces in the room, it helps to raise the temperature of the entire space.

[0008] 3. Fan Heater: A fan heater works by using electricity to power a heating element (such as a coil or metal block) and a fan. When the heating element is energized, it heats up and begins transferring heat to the surrounding air or objects. Simultaneously, a fan blows the heated air into the room, creating a warm airflow that helps raise the temperature of the space. Heat is generated by the resistance of the heating element to the flow of electricity. As electricity passes through the element, it encounters resistance, causing it to heat up. Fan heaters are generally very efficient and can be used to heat small areas or entire rooms.

[0009] 4. Baseboard heaters: These heaters are installed along the baseboards of the wall and use heating elements to warm the air drawn in through natural convection.

[0010] 5. Oil-filled Radiator: An oil-filled radiator is an electric heater that uses oil as the heat transfer fluid. It works by using electricity to heat the oil inside the radiator. As the oil heats, it begins to circulate within the radiator, transferring heat to the radiator's metal fins. These fins then radiate the heat outward, warming the surrounding air. The oil inside the radiator virtually never boils or evaporates, so it never needs to be replaced. This makes oil-filled radiators very efficient and durable. They are also safe to use, as there is no risk of the oil catching fire or producing harmful fumes. Oil-filled radiators heat up slowly but retain heat for a long time, making them a good choice for providing stable, consistent heat to a room. They are also relatively quiet and do not produce the dry, hot air that other types of heaters can produce. Inside the radiator is a heating element made of a conductive material, such as copper or aluminum. When electricity flows through the heating element, the resistance to the current generates heat. This heat is then transferred to the oil in the radiator, raising its temperature. The heating element is typically located near the bottom of the radiator, where the oil is at its lowest temperature. As the oil heats up, its density decreases and it begins to rise in the radiator. As the oil rises, it flows through the radiator's metal fins, transferring heat to the surrounding air. The hot oil then flows back to the base of the radiator, where it is reheated by the heating element and the heating process begins again. The oil temperature and the radiator's heat output can be controlled by a thermostat, which turns the heating element on or off as needed to maintain the desired temperature and / or provide a safety shutoff mechanism.

[0011] Electric heaters are generally efficient and can be used to heat small areas or entire rooms. They are easy to install and operate and do not produce harmful emissions.

[0012] The inventors have realized that better electric space heaters can be produced and have created the claimed solution. Summary of the Invention

[0013] According to a first aspect of the present invention, there is provided a fluid heater as claimed in claim 1 .

[0014] Advantageously, an electric space heater is provided that can use a combination of DC and AC power (i.e., without relying on AC input). Such a heater can intelligently utilize existing power options, thereby operating more efficiently while providing high performance and an environmentally friendly approach. The intelligent combination of AC and DC power significantly reduces the risk of disruption to a household's electricity supply or local grid (e.g., during peak demand periods, many appliances (not just heating appliances) may be connected to the mains AC). Furthermore, a fluid heater can be provided with generally higher peak power—for example, when a space needs to be heated for the first time from a cold state, the heater of the present invention can operate at a peak power significantly higher than using mains AC power alone. Furthermore, the intelligent use of DC power is useful in the event of a mains AC outage. The ability to control and balance the use of DC power in conjunction with conventional AC power to power an electric heating arrangement also addresses responsiveness issues: using a combination of AC and DC power can potentially heat the space faster than using mains AC power alone. This means that when a heating demand arises (e.g., via a direct user request, or via an indirect or automated system that predicts the user's anticipated demand), the space can be warmed more quickly. In some ways, spaces can be added before people even arrive at the space - this is more efficient; and better from a user experience perspective.

[0015] The heaters of the present invention can help avoid overloading electrical circuits, for example by avoiding reaching the limits of mains AC power delivery: for example, running several spot heaters could overwhelm the local electrical grid, such as the main circuit of a typical home - assuming 3kW space heaters, a home can only run 8 (before the mains power is overloaded at 100A). There are often other loads on the AC circuits of a home or office that need to be considered (especially during busy, high-demand periods). The power limits of household electrical outlets depend on the specific country and the type of outlet used. For example, in the United States, a standard 120-volt outlet can provide up to 15 amps of current, with a maximum power draw of 1,800 watts. However, some outlets in the United States are rated for 20 amps and can provide up to 2,400 watts. These are maximum ratings, and continuous operation of equipment at or near these limits is not recommended as it can be dangerous and may cause damage to the electrical system. In the United Kingdom, a standard household electrical outlet is rated for 230 volts and 13 amps of current, with a maximum power draw of 2,990 watts. However, as in the United States, these are maximum ratings, and continuous operation of the device at or near these limits is not recommended. This is because the current rating of the outlet also depends on the building's overall electrical system and the wiring within the walls.

[0016] By using the DC power supply of the present invention to replace or supplement the main AC power supply, the power demand load of the household circuits can be managed by smoothing or reducing its peaks (e.g., across the entire home). Thus, for example, the DC power supply can be recharged during periods of low household power demand (e.g., at night when people are asleep, or when a heater is turned off when someone leaves the room and the room becomes vacant). During periods of high household power demand, such as the morning peak hours (when many different devices are plugged in and using mains AC power), the DC power supply can be used to support or enhance the AC power, e.g., depending on the specific needs.

[0017] In some examples of the invention, it is possible to use the DC power source to provide additional power and heating in short pulses when it is most needed, such as when first heating a space from cold.

[0018] In some examples, the maximum power delivered via the combined AC and DC power is greater than that achievable using AC power alone. Typically, in some examples, a heating boost of at least 25% (measured in delivered kW heating power) can be provided when needed. This allows for a short period of intense heating when needed, followed by a gradual / abrupt termination of heating when the space temperature reaches a measured threshold or the user directly indicates that intense heating is no longer needed. In this way, the electric heating element can operate using only AC power.

[0019] At times when the AC grid load may be high, it may be desirable to reduce the amount of mains AC power used (e.g., while maintaining the same heat output, but not necessarily - the heat output may be slightly reduced, or may even be increased) to power the electric heating arrangement. In such cases, the controller of the heater of the present invention may be arranged to switch between using AC and DC power to power the arrangement to reduce the grid load. In some cases, the switching between using AC and DC may occur at approximately 50 Hz to reduce the average power drawn from the mains AC power. If the mains AC power is operating at 50 Hz, and the DC power output matches the RMS average output of the mains power, the DC power supply can meet approximately half of the heating demand while maintaining the same heating output as a conventional electric space heater if it were using only AC power. In such cases, the space heater of the present invention can reduce its load on the AC grid by approximately half without reducing heat output. Other AC + DC balancing configurations will be apparent to those skilled in the art, depending on the specific needs or desires of a particular system.

[0020] In some or all examples, the AC power source may be arranged to heat the space for a relatively long period of time (continuously); the DC power source may be arranged to:

[0021] By supplementing the AC power, the space is heated with greater power in a relatively short period of time;

[0022] to reduce the burden on the AC mains circuits; or

[0023] Increase the heating capacity of a space heater beyond that of AC power alone; or

[0024] Operate in a lower power mode than the mains AC power to reduce the overall energy consumption of the AC power; or

[0025] Operate in a lower power mode to reduce overall cost compared to using AC power; or

[0026] Allows safe unplugged (i.e., non-AC) operation for short periods of time or very low output operation for extended periods.

[0027] Optional features of the present invention are described in the dependent claims, thereby providing various advantages as discussed in the detailed description. These optional features improve the efficiency and intelligence of the heater arrangement of the present invention. It will be apparent to those skilled in the art that any of these optional features can be combined with other optional features. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0029] Figures 1 to 3 shows a schematic diagram of an electric space heater according to the first, second and third aspects of the present invention;

[0030] Figures 4a to 4d showing views from different angles and cross-sectional views of a fan blower space heater according to another aspect of the present invention;

[0031] Figures 5a to 5e showing views from different angles and cross-sectional views of a fan blower space heater according to another aspect of the present invention;

[0032] Figures 6a to 6e shows the first working configuration of Figures 5a to 5e Different angle views and cross-sectional views of a fan blower space heater;

[0033] Figures 7a to 7e shows views from different angles and cross-sectional views of a convection space heater according to another aspect of the present invention;

[0034] Figures 8a to 8d showing different angled views and cross-sectional views of an oil-filled radiator space heater according to another aspect of the present invention; and

[0035] Figures 9a to 9d Different angled views and cross-sectional views of an oil-filled radiator space heater according to another aspect of the present invention are shown. DETAILED DESCRIPTION

[0036] The exemplary embodiments described in the detailed description and claims are not meant to be limiting. Other embodiments may be used and other changes may be made without departing from the scope of the present invention. Various embodiments have been described. The specific embodiments are not intended to be exhaustive or to serve as limitations on the more broadly discussed and claimed aspects. Features described in conjunction with a particular embodiment are not necessarily limited to that embodiment and may be incorporated into any other embodiment. The protection afforded by any applicable doctrine of equivalents is retained to the greatest extent possible.

[0037] Terms such as upper, lower, top, bottom, left, right, inside, outside, vertical, upright, etc. have been used to simply and clearly describe the present invention. These terms should not be interpreted in a restrictive manner. Those skilled in the art will envision other suitable embodiments within the scope of the present invention.

[0038] Reference Figure 1 , schematically illustrating an electric space heater 1. Various aspects of the heater will be described in detail with reference to non-limiting examples. Additional details will be apparent to those skilled in the art. Specifically, those skilled in the art may combine and apply aspects of known electric space heaters (including those not described) to the present invention. The electric space heater is a stand-alone space heater that is independent of any central heating system; in some embodiments, it is a portable heating device designed to heat a small area or "space" rather than an entire room or building. In this embodiment, the space heater is also stand-alone, not relying on another energy source (e.g., like a central heating radiator that relies on heat from a central heater in a connected heated water circuit). Such central heating systems can use powerful heaters located within the circuit; stand-alone space heaters cannot. Those skilled in the art will be able to apply the described embodiments to other types of electric space heaters besides the one described. As is well known, these types of heaters can be used to directly heat the air surrounding the heater, heat the surrounding air via a heating fluid (e.g., oil in an oil-filled radiator), or heat the surrounding air via another medium (e.g., a heating block, such as a ceramic heating block).

[0039] Existing electric space heaters that heat the surrounding air are known in the art. Air typically flows over or through such heaters. In some cases, the air to be heated flows over an electric heating element (e.g., in a fan-blower space heater); in other cases, the electric heating element is enclosed in a housing along with a heating fluid (e.g., heating oil in an oil-filled radiator), and the radiator heats the surrounding air outside the housing.

[0040] In this example, the freestanding electric heater 1 is a convection heater. In other examples, the heater may be a fan blower heater, an oil-filled radiator, or any other type of electric heater. The heater 1 includes a heater housing 2 arranged to house its components. The heater of the present invention will generally need to be portable. In many examples, the present invention includes features that make the heater compact to allow the heater to be easily carried and moved, even if the heater of the present invention includes new components (as described in more detail below).

[0041] Heater 1 is arranged to heat the surrounding air. Relatively cool air enters heater 1 (represented by virtual input duct 4 in the figure) and is heated, and relatively warm air is then exhausted from heater 1 to the surrounding environment (represented by virtual duct 6 in the figure). These virtual ducts are drawn in the figure only to help clarify the description of the present invention; generally, convection space heaters generate airflow in a space due to the temperature difference between heated air and unheated air (as described above), and in this embodiment, there are no actual ducts.

[0042] Heater 1 comprises a first electric heating arrangement, including a first electric heating element 8 and a housing 10. Housing 10 is located within housing 2 between input port 4 and output port 6 and is arranged to house electric heating element 8. Electric heating arrangement housing 10 is arranged to heat air flowing through the heater and past housing 10. The housing is a protective housing to protect the exposed element 8 from wear and tear. In other examples, the housing may not be present; the heating arrangement is exposed.

[0043] In some embodiments, the electric heating arrangement may comprise a plurality of electric heating elements.

[0044] According to the present invention, the first electric heating element 8 is in communication with both a DC power source and an AC power source so that it can be powered by either or both of the power sources.

[0045] In embodiments where the electric heating arrangement includes multiple electric heating elements, some of the electric heating elements may be arranged to be powered solely by AC power, some may be arranged to be powered solely by DC power, and some may be arranged to be powered by both AC and DC power. Any combination of these options is possible, as will be apparent to those skilled in the art. This is especially true if the average AC power demand of the grid is lower compared to full or continuous AC power usage. Furthermore, peak AC power usage in residential homes (where such heaters are typically used) is also lower. Therefore, the system of the present invention is less likely to trip or cause items such as outlets to overheat (potentially leading to fires). In some examples, the controller is arranged to heat the electric heating arrangement via a mix of AC and DC power; using only AC and DC power at different times or under different usage scenarios; or any combination of the above. In this example, the DC power source is in the form of a battery pack 20, which is part of the heater 1 and located within the housing 2. In other examples, the DC power source may be external to the heater.

[0046] In this example, the AC power source includes mains power 22 (also known as “utility power,” “household power,” “household electricity,” “house current,” “power lines,” “household power,” “wall power,” “line power,” “AC power,” “city power,” “street power,” “water power”).

[0047] The heater further comprises a controller 24 arranged to control the distribution of power from the DC and AC power supplies 20, 22 to the first heating element 8. The controller may be implemented in hardware or software or a combination of both, as will be apparent to those skilled in the art.

[0048] In some examples, the controller is computer controlled and is arranged to control the amount of heating supplied to the surrounding air based on or in response to any one or more control factors, including: the capacity of the heating arrangement; the capacity of each heating element; the required amount of heating; the air input temperature at an input point within the heater housing; the air output temperature at an output point within the heater housing; the air temperature at any predetermined point within the heater housing; the air temperature at any predetermined point outside the heater housing (e.g., within the space to be heated); the amount of heating capacity available from the first heating element; the instantaneous heating demand; the predicted heating demand; and the flow rate of the air to be heated.

[0049] In addition, in some examples, the fluid heater includes one or more sensors (not shown) arranged to sense information related to one or more control factors and provide the control factor information to the controller. Some sensors are located within the heater housing (e.g., for measuring the air temperature within the heater or the flow rate of the air or heated fluid). Some sensors are located outside the heater housing (e.g., for measuring the air temperature or air flow rate at a desired location outside the heater (e.g., within a room in a building)). The controller operates based on the information from the sensors to instruct the electric heating arrangement to heat the fluid.

[0050] In some examples, the controller may have a memory (not shown) associated therewith (integrated or separate), the memory being arranged to store information regarding any one or more aspects of the system, such as historical or sensed information related to any control factor, control factor information, sensed information from any sensor, and desired output information (e.g., desired room temperature). The controller can access the information in the memory in a known manner. The controller and memory can be implemented in standard computerized networks and systems.

[0051] In this example, the controller 24 includes (not shown) a hardware thermostat and optionally a GUI thermostat so that a user can easily input desired heating requirements and easily receive feedback regarding heating operating parameters in a known manner.

[0052] In this example, the controller 24 also includes an AC power adapter (not shown) that is arranged to interface with the external AC power source 22 to deliver AC power at a desired power profile to the heating element 8. Although not shown in this embodiment, in some embodiments, a DC power adapter located between the DC power source and the heating element is similarly arranged to interface with the DC power source 22 to deliver DC power at a desired power profile to the heating element.

[0053] The controller is arranged to take various factors into account when controlling the power distribution to the heating elements. In some cases (at any given time), it may be desirable to use only DC power; in other cases (at any given time), it may be desirable to use only AC power; and in other cases (at any given time), it may be desirable to use a combination of DC and AC power. Example scenarios are listed above in the "Summary" section; other scenarios will be apparent to those skilled in the art.

[0054] The controller is configured to control the relative power distribution between the DC and AC power sources taking into account one or more of the following factors: the capacity of the heating arrangement; the capacity of each heating element (e.g., what is the maximum safe load (e.g., peak power or continuous power supply duration) for a particular heating element); the capacity of the or each power source; the instantaneous heating demand (e.g., whether the heater has just been turned on / whether the or each heater has just been started from a cold state); the predicted heating demand; and the instantaneous or predicted type of power source available (e.g., whether the remaining capacity of the DC battery is sufficient or whether the AC grid is currently heavily loaded). The controller may also be configured to provide a seamless transition from primarily using the DC power source to primarily using the AC power source, such as when the DC battery is depleted, the AC power source gradually or suddenly taking over while the power output remains substantially constant or maintained at a desired level; or when approaching or approaching an expected or measured peak AC load time, the AC power source gradually or suddenly taking over. The controller may also control intelligent charging of the DC power source so that the heat (of the DC battery) and the charge level are taken into account when controlling the charging (e.g., whether to charge aggressively / fast or slowly). In some examples, the DC power source is configured to simultaneously charge and power the electric heating arrangement. If the DC power supply comprises a battery pack having a plurality of battery cells, the controller is arranged to simultaneously: heat the electric heating arrangement using some of the battery cells of the DC power supply; and charge some (or all) other battery cells of the DC power supply.

[0055] In some examples, the first heating arrangement may have a preferred power demand range, and the controller is configured to supply power within the preferred power demand range while varying the ratio of AC to DC power to the first heating element from 0:100 to 100:0. Where the AC power source fully or largely meets the demand, a relatively low or zero DC power supply may be required. In some examples, the DC power source is sized such that 100% of the heating demand cannot be met by the DC power source alone. In other examples, a large DC power source is provided, and such demand can be met by the DC power source alone. Some examples are described later in this document.

[0056] In this example, the heater is an all-electric heater, that is, the heat source is entirely electric. In other examples, the heater can be partially electric, such as partially electric and partially natural gas, or partially electric and partially other combustible fuels - suitable combustible fuels can be combustible fluids, such as natural gas, hydrogen, or propane gas or methane gas, or ethane gas, or butane gas, or suitable combustible oils, or combustible solids or coverings, such as wood chips or wood pellets, or any combination thereof. In this way, some of the heating power is provided by the electric (DC and AC) components, while some is provided by more traditional combustion fuels. This helps to increase redundancy within the system, or can be used to operate efficiently in environments where one or another power source is scarce. In some examples of the present invention, if necessary, the combined DC and AC power sources are large enough to provide all or almost all of the power output of a typical heater. In other examples, the combustible fluid can provide most of the power output, while the power source provides supplementary heating. For example, the power source is particularly useful when the heater is first started up, because heating the space by burning fuel alone may be slow. In some cases, this is because the combustible fluid may be heated via a heat block (or similar), which may take time (eg, several minutes) to warm up from a cold state.

[0057] Reference Figure 2 , schematically illustrates an electric space heater 31 according to another example. Various aspects of heater 31 will be described in detail with reference to non-limiting examples. Additional details will be apparent to those skilled in the art. Specifically, those skilled in the art may combine and apply aspects of known electric space heater systems (including aspects not described) to the present invention.

[0058] In this example, the stand-alone electric space heater 31 is a convection heater. In other examples, the heater can be a fan blower heater or an oil-filled radiator, or any other type of electric space heater. The heater 31 includes a heater housing 32 arranged to house its components. The heater of the present invention will generally need to be portable. In many examples, the present invention includes features that make the heater compact to allow the heater to be easily carried and moved, even if the heater of the present invention includes new components (as described in more detail below).

[0059] Heater 31 is arranged to heat the surrounding air. Relatively cool air enters heater 31 (represented by virtual input duct 34 in the figure) and is heated, and relatively warm air is then exhausted from heater 31 to the surrounding environment (represented by virtual duct 36 in the figure). These virtual ducts are drawn in the figure only to help clarify the description of the present invention; generally, convection space heaters generate airflow in a space due to the temperature difference between heated air and unheated air (as described above), and in this embodiment, there are no actual ducts.

[0060] Heater 31 includes a first electric heating arrangement, including a first electric heating element 38 and a housing 40. Housing 40 is located within housing 32 between input 34 and output 36 and is configured to house electric heating element 38. Electric heating arrangement housing 40 is configured to heat air flowing through the heater and past housing 40. The housing is a protective housing to protect exposed element 38 from wear and tear. In other examples, the housing may not be present; the heating arrangement is exposed.

[0061] In some embodiments, the electric heating arrangement may comprise a plurality of electric heating elements.

[0062] According to the present invention, the first electric heating element 38 is in communication with both a DC power source and an AC power source such that it can be powered by either or both power sources.

[0063] In embodiments where the electric heating arrangement comprises a plurality of electric heating elements, some of the electric heating elements may be arranged to be powered only by AC power, some of the electric heating elements may be arranged to be powered only by DC power, and some of the electric heating elements may be arranged to be powered by both AC and DC power. Any combination of these options is possible, as will be apparent to those skilled in the art.

[0064] In this example, the DC power source is in the form of a battery pack 50, which is part of the heater 31 and is located within the housing 32. In other examples, the DC power source may be external to the heater.

[0065] In this example, the AC power source comprises mains power 52 .

[0066] The heater further comprises a controller 54 arranged to control the distribution of power from the DC and AC power supplies 50, 52 to the first heating element 38. The controller may be implemented in hardware or software or a combination of both, as will be apparent to those skilled in the art.

[0067] In this example, the controller 54 includes (not shown) a hardware thermostat and optionally a GUI thermostat so that a user can easily input desired heating requirements and easily receive feedback regarding heating operating parameters in a known manner.

[0068] In this example, the controller 54 also includes an AC power adapter (not shown) that is arranged to interface with the external AC power source 52 to deliver AC power to the heating element 38 at a desired power configuration.

[0069] The controller 54 also includes a DC-AC converter (not shown separately from the controller in the figure), which is located between the DC power supply and the heating element and is arranged to interface with the DC power supply 22 to convert the DC power to AC power in a known manner before delivering power to the heating element within the required power configuration.

[0070] In this example, the controller is arranged to control the output combination of the AC power supply and the DC power supply so that only AC power is delivered to the heating element. The benefit of this function is that the input circuit of the heating element is simpler than when AC and DC power are directly supplied to the heating element (thereby reducing the circuit connections to the electric heating element, thereby improving safety, maintenance and saving space).

[0071] In other examples, the controller may be arranged to control a combination of the outputs of the AC and DC power supplies to achieve different objectives.

[0072] In other examples, the heater may include an AC-DC converter (instead of a DC-AC converter), which is located between the AC power source and the heating element and is arranged to interface with the AC power source and convert the DC power to AC power in a known manner before delivering DC power to the heating element in the desired power configuration. Again, this feature has the benefit of making the input circuitry of the heating element simpler than when both AC and DC power are directly supplied to the heating element. In this case, in some embodiments, the AC-DC converter may be located inside the heater housing 32, while in other embodiments, it may be located outside the heater housing.

[0073] The controller is arranged to take into account a number of factors when controlling the power distribution to the heating elements. These factors have been discussed above in conjunction with Figure 1 The example discussed above also applies to this example.

[0074] The controller is configured to control the relative distribution of power from the DC and AC power sources, taking into account the above combined Figure 1 The factors discussed in the example above also apply to this example.

[0075] In some examples, the first heating element may have a preferred power requirement range, and the controller is arranged to supply power within the preferred power requirement range while varying the ratio of AC to DC power to the first heating element from 0:100 to 100:0. Figure 1 The examples discussed in the example also apply to this example.

[0076] In this example, the heater is an all-electric heater, i.e., the heat source is entirely electric. In other examples, the heater can be partially electric, such as partially electric and partially natural gas, or partially electric and partially other combustible fuels—suitable combustible fuels can be natural gas, hydrogen, or propane gas or methane gas, or ethane gas, or butane gas, or suitable combustible oils or wood chips or wood pellets, or any combination thereof. In this way, some of the heating power is provided by the electric (DC and AC) components, while some is provided by more traditional combustion fuels. This helps to increase redundancy within the system, or can be used to operate efficiently in environments where one or another power source is scarce. In some examples of the present invention, the combined DC and AC power sources are large enough to provide all or almost all of the power output of a typical heater, if necessary.

[0077] Reference Figure 1 and Figure 2 The features of the controller described, and the manner in which it intelligently distributes AC and DC power when powering the heating element, may be used in conjunction with the embodiments described later, and protection is specifically sought for any such combination.

[0078] Reference Figure 3 , showing the reference Figure 1 Unless otherwise stated, the technical features thereof are the same as those described with reference to any previously described embodiment (e.g., with reference to Figure 1 or Figure 2 ) are similar to the technical features described in the present invention. Heater 100 is used to heat the air in a standard household room space. Various aspects of the heater and heater system will be described in detail with reference to non-limiting examples. Additional details will be apparent to those skilled in the art. In particular, those skilled in the art may combine aspects of known space heater systems (including those not described) and apply them to the present invention.

[0079] In this example, heater 100 is a convection heater and includes a heater housing 102 that houses its components.

[0080] In this example, the freestanding electric heater 100 is a convection heater. In other examples, the heater can be a fan blower heater, an oil-filled radiator, or any other type of electric heater. The heater 100 includes a heater housing 102 that is arranged to house its components. The heater of the present invention will generally need to be portable. In many examples, the present invention includes features that make the heater compact to allow the heater to be easily carried and moved, even if the heater of the present invention includes new components (as will be described in more detail below).

[0081] Heater 31 is arranged to heat the surrounding air. Relatively cool air enters heater 100 (represented by virtual input duct 104) and is heated, and relatively warm air is then exhausted from heater 100 to the surrounding environment (represented by virtual duct 106). These virtual ducts are drawn in the figure only to help clarify the description of the present invention; generally, convection space heaters generate airflow in a space due to the temperature difference between heated air and unheated air (as described above), and in this embodiment, there are no actual ducts.

[0082] Heater 101 includes a first electric heating arrangement, including a first electric heating element 108 and a housing 110. Housing 110 is located within housing 102 between input 104 and output 106 and is configured to house electric heating element 108. Electric heating arrangement housing 110 is configured to heat air flowing through the heater and past housing 110. The housing is a protective housing to protect exposed element 108 from wear and tear. In other examples, the housing may not be present; the heating arrangement is exposed.

[0083] According to the present invention, the first electric heating element 108 is made of a Figure 1 A combined DC and AC power supply of the type described; in another example, the combined DC and AC power supply may be a reference Figure 2 or the type described in the relevant examples. For clarity, Figure 1 Most of the common parts shown in Figure 3 Repeated in (e.g., the controller and its associated circuitry).

[0084] In some embodiments, the electric heating arrangement may comprise a plurality of electric heating elements.

[0085] In embodiments where the electric heating arrangement comprises a plurality of electric heating elements, some of the electric heating elements may be arranged to be powered only by AC power, some of the electric heating elements may be arranged to be powered only by DC power, and some of the electric heating elements may be arranged to be powered by both AC and DC power. Any combination of these options is possible, as will be apparent to those skilled in the art.

[0086] In this example, the DC power source is in the form of a battery pack 120, which is also located within the housing 102. In this example, the heater is an all-electric heater, i.e., the heat source is entirely electric. In other examples, the heater can be partially electric, such as partially electric and partially natural gas, or partially natural gas and partially other combustible fuels—suitable combustible fuels can be natural gas, hydrogen, or propane gas or methane gas, or ethane gas, or butane gas, or suitable combustible oils, or combustible solids or coverings, or any combination thereof. In this way, some of the heating power is provided by the electric DC components and some by more traditional combustion fuels. This helps to increase redundancy within the system, or can operate efficiently in environments where one or another power source is scarce. In some examples of the present invention, the DC power source is large enough to provide all or almost all of the power output of a typical heater, if necessary.

[0087] In this example, the DC power supply has a capacity of 0.25 kWh.

[0088] Typically, the DC power capacity can be arranged to significantly increase the maximum performance of the space heater and / or allow the space heater to operate on DC power at at least a reasonably available power for a reasonably available amount of time. Some example configurations include:

[0089] 2kW to 3kW convection heaters with up to 1500W AC and up to 1500W DC. Models with this capacity range may include: 500Wh battery, 750Wh battery, or 1kWh battery. For example, a 500Wh battery can be used to provide 1kW AC and 1kW DC for half an hour, etc.

[0090] 2kW to 4kW oil-filled radiators – similar configurations, and batteries from 750Wh to 2kWh or higher.

[0091] Fan Heater - Contains DC batteries capable of running 250Wh at 1.5kW for up to 10 minutes. These can be added to 1.5kW of AC power for a total of 3kW. The powerful space heater of the present invention can provide at least 400Wh of power and has a combined (AC + DC) peak output of 5kW to 6kW. In this embodiment, the battery pack 120 includes a cell stack in a compact configuration.

[0092] In this example, the 0.25 kWh DC battery pack 120 includes 25 replaceable or rechargeable cylindrical cells, such as standard size 18650 cells (18 mm diameter and 65 mm length), each having a capacity of approximately 10 Wh. In this example, for compactness, the rechargeable batteries are arranged in a 5x5 stack, and the entire stack can be removed from the battery pack 120 and recharged from outside the housing 102. In another example, the stack can be configured differently - other suitable stacking configurations will be apparent depending on the available space in the battery pack. The battery stack is configured to provide substantially consistent usage over time for each battery within the battery stack in a known manner, such that the stack effectively operates as a single battery. In some examples, the DC power supply can also be charged from a renewable heat source, such as solar or wind power or a heat pump or any other suitable energy source.

[0093] In other embodiments, the DC battery pack may be charged in situ via a charging connection (not shown), ie, without removing any batteries from the housing 102 .

[0094] In some examples, such as this example, a DC power supply is spatially configured to simultaneously charge and power an electric heating arrangement. The DC power supply includes a battery pack having a plurality of cells. The controller is configured to simultaneously: heat the electric heating arrangement using some of the cells in the DC power supply; and charge some (or all) of the other cells in the DC power supply.

[0095] In this example, the battery pack is charged by an AC-DC converter (not shown), which in the case of in-situ charging the heater also includes within its housing.

[0096] A typical 18650 battery has a voltage of 3.6V. In this example, the batteries in battery pack 120 are arranged in series, resulting in an effective voltage of approximately 90V. The battery pack is well insulated. In other examples, the batteries can be arranged differently, such as all connected in series (so that the maximum voltage in any single path is 3.6V) or with several parallel paths of series-connected batteries, for example, five parallel paths, each with five series-connected batteries (18V).

[0097] In some embodiments, the battery may be arranged to provide substantially the same voltage as the AC input supply voltage - this makes combining AC and DC easier, and also makes charging easier. For example, in the UK, a 240V battery bank may be provided.

[0098] In some embodiments, multiple battery packs or stacks within battery packs are provided rather than a single battery pack.

[0099] In some examples, the capacity of the DC power pack is at least 50Wh, or optionally 100Wh. Thus, in a 400W heater, 100Wh of AC power can support 15 minutes. Alternatively, double that power for 15 minutes. There is no practical limit to the maximum capacity - the industrial stand-alone heater of the present invention may be equipped with a large capacity battery. In some cases, the DC power supply is arranged to have an output power of at least 200W; in other cases, at least 400W. The present invention provides a significant power boost compared to electric heaters using only AC power, for example, a 50Wh DC power pack used with the present invention can provide an additional 500W of operating power for 6 minutes (for example, in the UK, the total output power using a standard power socket is 3490W, and in the US it is 2900W (as mentioned above, there are other limitations)). A larger capacity power pack will provide longer operating times and higher power levels.

[0100] The heater 100 housing also uses its AC connection 130 to power small electronic components (which have relatively low power requirements compared to the power required to heat the air during normal heater operation), such as a controller, adapter, switching circuitry, heater display, heater user interface, sensors, Wi-Fi, Bluetooth, sub-1 GHz communications, etc., LED lighting, and other standard space heater components. Other such components may include: (thermal switch—sometimes specified separately from the temperature sensor by the manufacturer); thermostat; thermocouple / PRT; control PCB; multimedia interface; power electronics for the power pack; fan (a simple electrical device, or perhaps more complex with drive electronics). In some examples, this power can also be provided by a renewable heat source, such as solar or wind power or a heat pump or any other suitable energy source. In other examples, any one or a combination of these small electronic components can be powered directly from a DC power source.

[0101] In this example, the heater 100 also includes a controller (not shown) that is arranged to control one or more of: heating, battery charging, battery discharging, system requirements, as shown in FIG. Figure 1 The example described is the switching of a DC power supply.

[0102] The battery of the present invention generates some heat. Other electrical components of the heater also generate some heat. The inventors have recognized the need for a compact, efficient, non-standard cooling system.

[0103] The heater 100 of this embodiment also includes a cooling system (not shown). Due to the involvement of DC battery power, the additional switching required due to the intelligent use of DC batteries, and the operation of the controller and its associated circuitry (due to the intelligent use of DC-AC), the electronic components (controller, switches, adapter, etc.) may be hotter than a conventional heater.

[0104] In some examples, the heater includes a high-power switching module that is arranged to efficiently switch high currents so that the power can be varied within the same resistive electric heating element. This is particularly important in combined AC and DC modes to provide a fast-switching output that uses less average AC power, but maintains a stable overall combined power output of the heater. This feature allows for pulse width modulation within the control circuit. The high-power switching module can be arranged to switch 3, 5, 13, 15, 20 amps or more (e.g., 30 amps or even more).

[0105] In examples that include a battery charging mechanism, the inventors have further discovered that heat generation within the battery charging system can be a problem—particularly in AC-DC converter battery charging systems that allow for voltage charging of DC battery packs / batteries. This type of battery charging system is not currently available in any electric space heater systems or heater housings and generates heat. Therefore, another advantage of some examples of the present invention is the use of a cooling system (or provision of a separate cooling system) as a heat sink to cool the battery charging mechanism. A battery charging mechanism cooling system is particularly useful because charging can (and should) occur when the heating system is not on (i.e., when it is not heating the building, such as in the middle of the night, or when a user is detected to have left the space (e.g., if a sensor detects someone leaving a heated room)). The cooling system of the present invention allows the heating system to operate to remove heat during charging. Even when heating is not required, the controller can be arranged to force cool air through the heater (e.g., by operating a fan) to cool the battery charging mechanism. For example, the controller can react in response to a prediction, notification, or sensing that the battery charging system should be cooled (e.g., via feedback from a temperature sensor located near the battery charger or after a threshold minimum period of continuous battery charging). This battery charging mechanism cooling feature can be implemented with any of the described embodiments including a battery charger to create new embodiments of the present invention.

[0106] In some examples (e.g., where the flow of ambient air participates in the cooling), when the heating system is operating (e.g., heated air is required), cooling occurs by the flow of cool air to be heated through any, some, or optionally all of the controller / battery / battery charger / adapter / any other control electronics. However, when the heating system is not operating, the present invention allows the charger cooling system to operate (either through the flow of ambient air or through its own dedicated coolant within its own dedicated coolant loop) specifically for the purpose of cooling the battery charger. This feature is particularly useful in examples of the present invention with high-power charging systems (which can be applicable to larger batteries or smaller batteries that can be charged quickly, or any combination of the two).

[0107] In some examples, the cooling system uses some of the cool air that reaches the cold input 104 to cool the hotter electronic components (ideally, the intention is to keep the electronic components well below 100°C). In some examples, elements of the cooling system include drawing cool air from the input 104 within the heater 100 and positioning it adjacent to or near the components that need cooling. As a result, the overall efficiency of the heater is improved, and its electronic components can be smaller / simpler because the need for switching power for full electronic efficiency is reduced.

[0108] The cooling system in some examples includes a coolant circuit having a closed coolant piping system (not shown) through which the coolant is pumped. The closed coolant piping system is configured to facilitate heat transfer between the coolant and the cold air input of the heater to transfer heat to the cold air input of the heater, and to facilitate heat transfer between the coolant and the battery cells or other components to transfer heat to the cold air input of the heater. This is achieved by routing the piping system to appropriate locations near any one or more of the boiler components, the battery cells, and the cold water input.

[0109] In many embodiments, the DC power supply battery and electronic components are protected from the heat of the electric heating arrangement. In some examples, the electric heating arrangement is located above the DC power supply battery and / or electronic components to protect them (from the rising hot air). In other examples, the DC power supply battery and / or electronic components can be located to the side of the heating element. In some examples, the DC power supply and / or sensitive components can be located above the heating element; in these examples, the heat generated by the heating element may be deflected around the battery / PCB, etc., for example, via one or more physical deflectors, which may be heat-reflective deflectors. In addition, the housing can protect the heating element from direct infrared heat simply by blocking the direct line of sight; therefore, in some examples, the DC power supply and / or other sensitive components are located in a separate portion of the housing and are appropriately separated from the heating element.

[0110] In some examples, the housing 100 includes an access door arranged to allow access to the internal components of the heater (e.g., for servicing or repair), and the DC power supply is arranged within or integrated with the access door. This also increases the overall compactness and ensures that the internal components of the heater can be accessed (e.g., for servicing / repair) without further removal or manipulation of the DC power supply.

[0111] In this example, the heater 100 further includes a thermal break or thermal shield (not shown) located between the DC power supply and the first heater arrangement and between the controller and the first heater arrangement. The thermal break or thermal shield may include any one or any combination of the following: an air gap; a gap filled (partially or completely) by a thermally insulating material; a gap filled (partially or completely) by an infrared reflective material; or a gap filled (partially or completely) by an insulator or a low thermal conductivity material.

[0112] In some examples, a heat shield may include an associated heat shield cooling mechanism arranged to transfer heat from the heat shield area to another area where it is safer to dissipate the heat, and including any one or more of the following:

[0113] A fluid material such as air or water that carries heat away from an area (e.g., from the heat shield area to a dissipation area (i.e., another area that is safer to dissipate heat than the heat shield area));

[0114] Active cooling mechanisms, such as Peltier devices (actively transfer heat from one side to another, e.g. to another area that is safer to dissipate the heat than the heat shield area);

[0115] A freezer cabinet or freezer block (similar to a typical refrigerator) located within the heater and arranged to substantially enclose the DC power supply;

[0116] and

[0117] • An air flow mechanism, such as a blower, is arranged to draw air from outside the housing or from inside the housing to provide the required cooling effect.

[0118] In another embodiment (not shown), the heater comprises a hybrid electric-gas heater housing, rather than a housing containing only electric heating elements. In this embodiment, multiple heating mechanisms are located within the same sealed heater housing cavity. One is an electric heating mechanism (similar to the mechanisms described in other embodiments); the other is a gas burner mechanism. Gas burner mechanisms are of known types. In addition to natural gas, the other mechanisms can be burners of various fuels (e.g., hydrogen, propane, oil). The electric heating mechanism can be of any suitable form. In this example, it is in the form of an electric heating element. In one example, the heater can be arranged to heat the air within the space. The electric heating element or elements can be located anywhere within or around the burner housing, allowing the air to be heated by either or both the gas and electric heating mechanisms. The heating element can be an electrical wire that can be heated by passing an electric current through the wire and is appropriately arranged to transfer heat to the desired location (e.g., wrapped around piping or any other component within the burner housing). In some examples, the power supply is arranged to provide preheating when the hybrid heater is first turned on, and when the combustible fuel alone is needed to assist in raising the space to the desired temperature. In some cases, this is because the combustible fluid may be heated via a heating block (or similar), which takes time (eg, several minutes) to warm up from a cold state.

[0119] A heat exchanger may be located within the gas burner housing. The heat exchanger is arranged to concentrate heat from the combustion gases, the electric heating element, or both, into the air to be heated. The heat exchanger may be metal or ceramic. In one example, the heat exchanger may be in the form of one or more plates (e.g., metal plates) positioned adjacent to the air to be heated. The electric heating element may be positioned between the plates. In another example, a block of suitable material (e.g., a ceramic block) may be positioned adjacent to the air to be heated.

[0120] More specific examples of the present invention will now be described with reference to schematic diagrams illustrating some of the key elements of these examples. Other elements of the examples may not be shown or described, but will be apparent to those skilled in the art. Specifically, all examples may be combined with any of the features described above (e.g., Figure 1 、 2 or 3) in combination, and all such combinations are disclosed by this specification. For example, tip or drop sensing with automatic shutoff function; various controller control factor options; different battery capacity options; different power balancing AC-v-DC options.

[0121] In some of these examples, the DC + AC power combination is arranged to increase the peak power of the electric heating arrangement by at least 25% relative to using AC alone; in other examples, by at least 50%, and in other examples by at least 100% (i.e., if approximately 100%, the output is doubled); and in yet another example, by significantly more than 100%.

[0122] Example 1: Fan Blower Space Heater ( Figures 4a to 4d )

[0123] The electric space heater comprises a fan-blower space heater 400, which is arranged to heat a space, such as a room. The heater has a housing 402, which includes feet 440, which are arranged to provide a wide and stable support for placing the heater on a flat surface. The housing has an air inlet 404, through which air from the room can enter the housing, and an air outlet 406, through which heated air can exit the housing and enter the room.

[0124] The heater includes a first electric heating arrangement, comprising a coiled electric heating element 408, which is arranged to heat air flowing over or passing through its coils. The heater includes a fan 480, which is arranged to blow air heated by the heating element 408 into the space to be heated. In this example (which may vary in other examples), the coiled heating element and the fan are both coaxially mounted relative to the housing so that they are aligned with the air inlet 404 and the air outlet 406. Thus, the fan is also provided to draw air to be heated from the space into the electric heating element.

[0125] The heating element 408 may be of any of the types previously described and arranged to be powered by a mains AC power supply or a DC power supply as described in other examples above.

[0126] The heater further comprises power electronics 424, including a controller arranged to control the distribution of power from the DC power supply and the AC power supply to the heating element in a manner similar to that described above with respect to the previous embodiment. The power electronics 424 further comprises an AC power interface arranged to interface with a mains AC power supply. The power electronics are located below the first electric heating arrangement, thereby mitigating any adverse heating effects of the heating arrangement on the power electronics.

[0127] In this example, the heater includes a DC power source in the form of a battery pack 420 comprising an array of easily accessible rechargeable batteries. The battery pack is located below the first electric heating arrangement, thereby mitigating any adverse heating effects of the heating arrangement on the battery pack.

[0128] In this example, the peak power is 400W. In other examples, the peak power may be lower, for example, for a smaller automotive cabin heater version. In other examples, the peak power may be higher, for example, up to 3kW for a domestic example or over 10kW for an industrial fan blower heater. Typical peak power for a space heater according to the present invention will be in the range of 1500W to 2000W. Such space heaters typically have multiple heating settings; for example, in one example, the low and high settings may provide peak powers of 1kW and 3kW, respectively.

[0129] The heater assembly and housing are configured to ensure that airflow is isolated from the battery and electronics, as will be described in more detail below. Physically, heat is always located above the battery and electronics to protect them (hot air rises, etc.).

[0130] Housing 402 is a compartmentalized housing with two chambers: a first upper chamber containing a heating element 408 and a fan 480, and a second lower chamber containing a battery pack 420 and power electronics (including a controller and AC power interface) 424. In this example, the upper chamber is located directly above the lower chamber. Each chamber is relatively enclosed. In this example, the housing includes a partition wall 403 between the upper and lower chambers—the partition wall 403 is arranged to protect the battery pack and control electronics from the direct infrared heat of the heating element by blocking direct line of sight. When in use, the first chamber is located above the second chamber, which also ensures that convective heat from the heating element 408 does not adversely affect the battery pack and control electronics 424. In addition, because the air inlet and outlet of the fan, electric heating element, and heater housing are all aligned within their respective chambers, air is directed along the desired path without naturally flowing through the second chamber (i.e., without affecting the battery or controller electronics).

[0131] Example 2: Fan Blower Space Heater ( Figures 5a to 5e and 6a to 6e)

[0132] The electric space heater comprises a modular fan blower space heater 500 arranged to heat a space, such as a room. For clarity, Figures 5a to 5e shows a space heater with its separated modules, and Figures 6a to 6e A space heater with modules assembled into one operating configuration is shown. Note that the modular space heater can also be assembled in a different operating configuration, as will be explained in more detail below.

[0133] The housing has an air inlet 504 through which air in the space can enter the housing, and an air outlet 506 through which heated air can leave the housing and enter the space.

[0134] The heater includes a first electric heating arrangement, which includes a coiled electric heating element 508, which is arranged to heat air flowing over or passing through its coils. The heater includes a fan 580, which is arranged to blow air heated by the heating element 508 into the space to be heated. In this example (other examples may vary), the coiled heating element and the fan are both coaxially mounted relative to the housing so that they are aligned with the air inlet 504 and the air outlet 506. Therefore, the fan is also provided to draw air to be heated from the space into the electric heating element.

[0135] The heating element 508 may be of any of the types previously described and arranged to be powered by a mains AC power supply or a DC power supply as described in other examples above.

[0136] The heater further comprises power electronics 524, which are arranged to control the distribution of power from the DC power supply and the AC power supply to the heating element in a manner similar to that described above with respect to the previous embodiment. The power electronics 524 also comprises an AC power interface, which is arranged to interface with the mains AC power supply. The power electronics are located below the first electric heating arrangement, thereby mitigating any adverse heating effects of the heating arrangement on the power electronics.

[0137] In this example, the heater includes a DC power source in the form of a battery pack 520 comprising an array of easily accessible rechargeable batteries. The battery pack is located below the first electric heating arrangement, thereby mitigating any adverse heating effects of the heating arrangement on the battery pack.

[0138] In this example, the present invention provides a 500Wh fan heater with a peak DC output of 2.5kW and a maximum AC heating system output of 2.5kW. This allows for a total output power of up to 5kW. However, the heater can be controlled by the controller to operate in a low-power mode, providing 250W AC and 250W DC, allowing the battery pack to last for a long time, approximately 2 hours.

[0139] Heater 500 has a modular housing comprising three modules: a base module 502a, which is arranged to house power electronics 524 and interface with an AC power source and has an air inlet 504 formed therethrough; a middle module 502b, which is arranged to house a DC power source 520; and a top module 502c, which is arranged to house an electric heating element 508 and a fan 580 and has an air outlet 506 formed therethrough. The base module, middle module, and top module are arranged to be plugged together to form a plurality of operating configurations of the heater housing, as described below. In other examples, the modules may be connected together by any suitable mechanism, including one or more of a slot fit, a clip fit, a friction fit, a screw fit, and a bolt fit.

[0140] In this example, base module 502a includes a base 540 configured to elevate the bottom of the space heater, allowing the air intake to be located and formed on the bottom of base module 502a (the surface facing downward during use). Thus, the air intake is elevated from the surface on which the space heater is placed and formed through the bottom surface of the heater. This aligns the air intake, DC power supply, heating element, fan, and air output, providing an efficient and ideal air flow path.

[0141] The base also provides a wide and stable support for placing the base module on a flat surface.

[0142] In this example, a grille 550 is provided at the air outlet opening to improve operational safety (preventing large objects / fingers from contacting the heating element and fan) while allowing heated air to flow freely out of the heater.

[0143] In this example, the housing is generally cylindrical and each module of the housing has a corresponding contour to provide a smooth shape and pleasing aesthetic appearance while allowing efficient operation. The housing is elongated (to allow the required alignment of the components as described above).

[0144] Advantageously, modular heaters can be configured in multiple operating configurations. The base module can be connected directly to the top module or the middle module. The top module can be connected directly to the base module or the middle module. The middle module can be connected to both the base module and the top module.

[0145] In the first working configuration (such as Figures 6a to 6e All three modules can be used together to provide heating via AC and DC power.

[0146] In a second operating configuration (not shown), the bottom and top modules can be used together (without the middle module) to provide heating via AC power alone.

[0147] The controller 524 is configured to identify (e.g., via a suitable sensing mechanism) which modules are connected to which operating configuration. Based on this identification, the controller can control the power supply (alternating current only or a smart combination of alternating current + direct current) to the electric heating element accordingly.

[0148] The battery elements can be charged without removing the battery pack from the mid-module. In a second configuration, the heater can operate without the mid-module, for example while the battery pack is recharging.

[0149] Advantageously, in the first operating configuration, the battery pack and control electronics are located upstream of the heating element in the airflow path defined by the fan. Thus, during use, relatively cool air flows over the battery pack and control electronics, cooling them (as they would otherwise generate unnecessary heat during operation). This arrangement also allows the air to be preheated before reaching the heating element, making the overall heating process more efficient.

[0150] Likewise, in a second operating configuration, the control electronics are located upstream of the heating element in the air flow path defined by the fan, with similar advantages.

[0151] Therefore, no other cooling system is needed in this example.In other examples, the present invention provides another cooling system, for example, providing separate cooling systems for the electronic components (one or more of the controller, adapter, battery charger) and the battery pack.

[0152] As with the other examples, the heat is physically located above the battery and electronics to protect them (hot air rises, etc.).

[0153] The combined housing 502a, 502b, 502c of this modular, portable fan heater example is approximately 20 cm in diameter and approximately 35 cm in height. Other size and shape options will be apparent to those skilled in the art.

[0154] Example 3: Convection Heater ( Figures 7a to 7e )

[0155] The electric space heater comprises a convection space heater 700, arranged to heat a space, such as a room. The heater comprises a housing 702, which includes a bracket 740 arranged to facilitate securely mounting the convection heater to a wall in a known manner. The housing has a series of holes along its lower surface, serving as air inlet holes 704, through which air from the room can enter the housing; a series of holes along its upper surface, serving as air inlet holes 706, through which air from the room can enter the housing; and a series of holes along its upper surface, serving as outlet holes 706, through which heated air can exit the housing and enter the room. As previously described, the air heated by the convection heater rises and is replaced by cooler air from the room, forming a stream of warm air that circulates throughout the room. This is achieved via holes 704 and 706.

[0156] The heater comprises a first electric heating arrangement comprising two nickel-chromium electric heating elements 708 arranged to heat air flowing over or past them. The heater in this example does not include a fan; natural convection drives the air heated by the heating elements 708 into the space to be heated.

[0157] The heating element 708 may be of any type previously described and arranged to be powered by mains AC power or DC power as previously described with respect to other examples.

[0158] The heater further includes power electronics 724, which are arranged to control the distribution of power from the DC power supply and the AC power supply to the heating element in a manner similar to that described above with respect to the previous embodiment. The power electronics 724 also includes an AC power interface, which is arranged to interface with the mains AC power supply. The power electronics are located below the electric heating arrangement, thereby mitigating any adverse heating effects of the heating arrangement on the power electronics.

[0159] In this example, the heater includes a DC power source in the form of a battery pack 720 comprising five rechargeable batteries. The battery pack is located below the first electric heating arrangement, thereby mitigating any adverse heating effects of the heating device on the battery pack. In this example, the controller includes a battery charging mechanism, and the battery pack is arranged to be charged locally via the power electronics.

[0160] In this example, the convection heater is suitable for home use and has a peak power of 1 kW. In other examples of home convection heaters, the peak power may be 500W to 3 kW.

[0161] The heater assembly and housing are configured to ensure that airflow is isolated from the battery and electronics, as described in more detail below. Heat is always physically located above the battery and electronics to protect them (hot air rises, etc.).

[0162] The housing 702 is a compartmentalized housing having two chambers: a first upper chamber containing the heating element 708 and a second lower chamber containing the battery pack 720 and power electronics (including a controller and AC power interface) 724. In this example, the upper chamber is located directly above the lower chamber. Each chamber is relatively enclosed. The housing includes a partition wall 703 between the upper and lower chambers - the partition wall 703 is arranged to protect the battery pack and control electronics from the direct infrared heat of the heating element by blocking the direct line of sight. When in use, the first chamber is located above the second chamber, which also ensures that convective heat from the heating element 708 does not adversely affect the battery pack and control electronics 724. In addition, because the electric heating element and the air inlet and outlet of the heater housing are all located in their respective chambers, air is directed to the desired path and does not naturally flow through the second chamber (i.e., without naturally affecting the battery or control electronics). In this example, it is noteworthy that the wall 703 does not seal the upper and lower chambers from each other; an airflow path is left to allow air to flow freely from the air inlet to the air outlet.

[0163] In addition, the convection heater has another heat shield 705 to protect the DC power supply and control electronics from the heat of the electric heating element. The heat shield allows air to flow through, so that air can flow freely from the air inlet to the outlet. In this example (see Figure 7e ), the heat shield comprises a horizontal plate located below the electric heating element and above the battery and control electronics. The horizontal plate does not contact the inner wall of the heater housing so that some air is allowed to flow through the horizontal plate. In other examples, the horizontal plate can be or additionally have holes running through it to allow air to flow through. In this example, the two heat shields 703 and 705 work well: the upper heat shield 703 can become warm enough to dissipate heat, while the lower auxiliary heat shield 705 is arranged to protect the batteries and other components in the lower chamber from the heat dissipated by the upper heat shield. Alternative configurations of the heat shield (e.g., other than a plate) will be apparent to those skilled in the art.

[0164] In other examples (not shown), the convection heater may alternatively or additionally have a thermal break or thermal shield, or both, between the battery (and / or power electronics) and the housing 702 (which may undesirably conduct heat from the heating area (near the heating element) to the battery and / or power electronics). The same types of thermal breaks (e.g., air gaps) or thermal shields as described previously with respect to the other examples may be used. The thermal break may comprise the housing itself, with the housing having built-in breaks (e.g., strips of insulating material (e.g., ABS plastic or nylon) between portions of the housing (e.g., metal portions))—in which case the metal housing enclosing the heating element may become and remain hotter than the metal housing enclosing the battery, e.g., the housing surrounding the upper chamber may be hotter than the housing surrounding the lower chamber.

[0165] Example 4: Oil-filled radiator ( Figures 8a to 8d )

[0166] The electric space heater comprises an oil-filled radiator space heater 800, which is arranged to heat an air space, such as a room. As previously discussed, air is heated by the radiator heater, which radiates heat outward, warming the surrounding air. Figure 8a , arrows 804, 806 are shown to depict this process.

[0167] The heater has a two-part housing. The first part of the housing is a radiator housing 802a, which contains: a first electric heating arrangement 808; and a heating fluid, in this example oil. The second part of the housing is an electrical component housing 802b, which contains a battery pack 820 and power electronics 824. These features will be described further below. The radiator housing has metal fins as shown. The housing also includes feet 840, which are arranged in a known manner to provide a stable support for placing the heater on a flat surface.

[0168] The heater includes a first electric heating arrangement, which includes an electric heating rod 808, which is arranged to heat the oil flowing through it within the radiator housing 802a. In this example, the heater does not include a fan; the metal fins of the radiator housing are heated by the hot oil inside and dissipate the heat to the space to be heated. In use, the oil at the top of the radiator is warmer than the oil at the bottom (hot fluid rises). After the oil dissipates heat to the surrounding environment through the fins, it sinks to the bottom. The electric heating rod 808 is located near the bottom of the housing 802a. The cold oil is heated, rises, and the process repeats.

[0169] The heating element 808 may be any type of heating element previously described and arranged to be powered by a mains AC power supply or a DC power supply as previously described with respect to other examples.

[0170] The heater further comprises power electronics 824, including a controller arranged to control the distribution of power from the DC power supply and the AC power supply to the heating element in a manner similar to that described above with respect to the previous embodiment. The power electronics 824 further comprises an AC power interface arranged to interface with a mains AC power source. The power electronics are located to the side of the electrical heating arrangement in a separate portion of the housing (i.e., the electrical component housing 802b), thereby mitigating any adverse heating effects of the heating arrangement on the power electronics.

[0171] In this example, the DC power source takes the form of a battery pack consisting of six easily accessible modules. Each module includes a group of battery cells electrically connected in series. In this example, the battery modules are arranged in a 3x2 configuration for compactness. Each module can be easily removed for charging.

[0172] The battery pack is located to the side of the electrical heating arrangement in a separate portion of the housing (ie, electrical component housing 802b), thereby mitigating the adverse heating effects of the heating arrangement on the battery pack.

[0173] It is noteworthy that the two parts of the housing 802a, 802b are arranged to be securely connected together in use so that the contents of the electrical component housing 802b are thermally isolated from the contents of the heat sink housing 802a.

[0174] Furthermore, the two parts of the housing 802a, 802b are arranged to be securely connected together when in use, so that the power electronics 824 are located close to the electrical heating arrangement, thereby minimizing the amount of wiring required between the two - facilitating assembly and reducing wiring paths, etc.

[0175] The two parts of the housing 802a, 802b can be easily separated when needed, for example, the electrical component housing 802b can be easily removed to allow access to the battery and power electronics for charging or replacement / repair.

[0176] In some examples, the controller includes a battery charging mechanism, and the battery pack is arranged to be charged locally via the power electronics.

[0177] In this example, the heater 800 is suitable for home use and has a peak power of 1 kW. In other home use examples, the peak power may be 800W to 2.5 kW.

[0178] Example 5: Oil-filled radiator ( Figures 9a to 9d )

[0179] In this example, the space heater includes an oil-filled radiator 900 similar to that of Example 4. For the sake of clarity, similar features are not repeated. Radiator 900 differs from radiator 800 in that its battery 920 and power electronics 924 are located in an electrical component housing 902b below the radiator housing 902a. The radiator lacks feet and is instead supported by four wheels 940 arranged for stable support on flat ground and easy portability.

[0180] Example 6: Infrared Radiant Space Heater (not shown)

[0181] Infrared radiant space heaters are within the scope of the present invention. Those skilled in the art will appreciate that these heaters operate similarly to the aforementioned heaters and, in one example, may have a peak power of 300 W. In other examples, they may have a peak power of at least 1 kW, and possibly even 3 kW.

[0182] Example 7: All-Electric Patio Space Heater (not shown)

[0183] All-electric patio space heaters are within the scope of the present invention. Those skilled in the art will appreciate that such heaters operate similarly to the aforementioned heaters and, in one example, may have a peak power of 1500 W. In other examples, they may have a peak power of at least 5 kW, and possibly even 10 kW.

[0184] Example 8: Hybrid Gas-Electric Patio Space Heater (not shown)

[0185] Hybrid gas-electric patio space heaters are within the scope of the present invention. Those skilled in the art will appreciate that these heaters operate similarly to the aforementioned heaters and, in one example, may have a peak power of 1000 W. In other examples, they may have a peak power of at least 3 kW, and possibly even 7 kW.

[0186] Example 9: Hybrid Combustible Fuel-Electric Hot Spot Space Heater (not shown)

[0187] Hybrid combustible fuel-electric hot spot space heaters are within the scope of the present invention. Those skilled in the art will appreciate that these heaters operate similarly to the aforementioned heaters and, in one example, may have a peak power of 500 W. In other examples, they may have a peak power of at least 2 kW, and possibly even 5 kW.

[0188] Various modifications may be made thereto without departing from the scope of the invention.

[0189] Alternatively, in some examples of heaters that include two (or more) heating elements, the controller can be arranged to power the first heating element only via a DC power source and the second heating element only via an AC power source. This feature reduces the need for more complex circuitry and therefore reduces the risk of circuit failure. Furthermore, if one power source fails, the other power source will still function.

[0190] In other examples, the heater comprises an industrial-sized furnace-style air heater (similar to the portable space heaters described above but larger).

[0191] In any example, the AC power may be disconnected (or unavailable, such as during a power outage), and the heater may operate solely on DC power.

[0192] In some examples, the DC battery capacity can be at least 0.1 kWh, such as about 0.2 kWh or about 0.5 kWh or about 1 kWh. In some examples, the peak power output can be a combination of about 3 kW DC and 3 kW AC.

[0193] More than one heating element may be provided per heater housing.

[0194] For any embodiment described as being purely electric, those skilled in the art will appreciate that it may alternatively be configured as part electric - part combustible fuel.

[0195] Any example may include a DC power interface arranged to receive a DC power source, wherein the DC power interface is configured to receive more than one type of DC power source, such as a nickel-metal hydride battery cell pack, a nickel-cadmium battery cell pack, and a lithium battery cell pack, or any hybrid pack containing a mix of any of these cell types. The supercapacitor may replace or supplement a conventional DC battery pack to provide the DC power source.

[0196] Any example including a DC power supply unit may include a safety disconnect mechanism arranged to disconnect the unit from the power supply to the electric heating element. The safety disconnect mechanism may include a main switch or an automatic main switch; in some examples, the safety disconnect mechanism includes a contactor. Advantageously, a safe and simple DC switching mechanism is provided. Specifically, for floor-standing or portable space heaters, if the heater is detected to have tipped over or lifted from a flat or stable surface, the safety mechanism is triggered. The space heater may be provided with one or more feet arranged to be stably placed on a flat surface.

[0197] This safety mechanism (fall sensing mechanism) is particularly important to the present invention because if the heater is knocked over, heat may leak into the battery cells, posing a greater hazard than with traditional space heaters.

[0198] Electric heating elements, or batteries, or both, along with a control mechanism (e.g., control electronics and / or software) can be installed into an existing electric space, gas (or other combustible fuel), or hybrid gas-electric heater to provide a heater within the scope of the present invention, thereby controlling the amount of heating provided by direct current, alternating current, or a combination thereof.

[0199] The space heaters of the present invention can be more powerful and more efficient than those described previously. Such examples are particularly suitable for retrofitting electric heating functionality to existing AC electric heaters or gas heaters. For example, the electric heating element can be coated, sprayed, housed, wrapped, partially or fully embedded, or otherwise connected to a section of duct located at or near: its outlet from the combustible fuel burner housing; its inlet to the burner housing; or both. The heating element can be powered by direct current, alternating current, or a combination of the two. In some examples, a battery (such as a large battery of the type described above) can be mounted on the burner housing together with a control mechanism (such as control electronics and / or software) to control the heat provided by the electric heating element relative to the combustible fuel source. When connected to an AC electric heater, a DC power pack and appropriate control electronics can be added to balance the use of DC and AC power according to demand and / or supply.

[0200] In any, all, or some embodiments, a battery charging mechanism is provided that is arranged to charge the DC power source taking into account and in response to one or more of: the current DC power source battery charge; the capacity of each power source; the instantaneous heating demand; the predicted heating demand; the instantaneous or predicted type of supply available; and household demand, local demand, national demand, international demand, or any combination thereof. Typically, the battery pack is charged during low demand periods, such as late at night or in the middle of the day (when the controller is informed that AC power demand (not necessarily just from heating) is generally low, or in some cases when the controller is informed that grid power demand is low).

[0201] In any of the examples described, each heating element can be any element that generates heat when an electric current passes through it, such as any resistive wire or array of resistive wires that generates heat when an electric current passes through it, such as (but not limited to):

[0202] Thin films (polyimide on conductive metal);

[0203] Ceramic (nickel-chromium-aluminum embedded in ceramic sheath, etc.) wire;

[0204] Bare wire (nickel, nickel-chromium alloy, Kanthal, Stellite, etc. tungsten);

[0205] Encapsulated wire – e.g. silicone-encased nickel-chrome;

[0206] Aluminum-clad resistor elements (e.g., die-cast), where the resistor element is electrically isolated from the aluminum housing;

[0207] Mineral insulated wire - copper sheathed / nickel-chrome, cupronickel / Inconel, steel sheathed / nickel, Inconel sheathed / nickel alloy wire, and various mixtures of these. Components can be drawn to size or manufactured to final dimensions. Insulation is typically Al2O3 or MgO;

[0208] Regular wires, spiral wires, busbars with winding elements in the middle.

[0209] Suitable alternative materials for use with similar arrangements will be apparent to those skilled in the art.

[0210] In any example describing a single heating element, it can be replaced by one or more different heating elements, as will be apparent to those skilled in the art. For example, the one or more electric heating elements can include a conductive heating element coating applied to any one or more of the inner surface of the heater, the outer surface of the heater, or any other component. The one or more electric heating elements can include induction heating elements, for example, so that it / they can be powered by induction (without direct contact).

[0211] In some cases, multiple different electric heating elements are arranged to heat the air in different parts of the heater. In some examples, multiple sections of different heating elements are provided within the heater, and each section can be controlled together or individually, for example, to provide different levels of heating at different sections. This is particularly useful in situations where different heating levels may be appropriate for different locations in the heater - it may be necessary to provide different heating levels in different parts of the air path, for example, during initial heating startup, when the air is first heated from a cold state. For example, when heating is first required, it may be possible to provide stronger heating at the beginning of the air path than at the end because the initial input air is particularly cold.

[0212] In some of these examples, the elements may be fully embedded in the heater housing such that no portion of them is exposed or protrudes from the conduit (eg, no external electrical connection points).

[0213] In some examples where the heating elements will be positioned in different areas (not continuously along the entire length of the heater housing), gaps between the different areas can be formed by masking the gap portions of the housing surface during the coating / spraying process (e.g. using a spray mask).

[0214] In some examples, the present invention provides a single-shell space heater having an electric heating element arranged to be powered by a large DC power supply and an AC power supply, and equipped with an onboard controller and a controller cooling system. The inventors have recognized that the components of such a system have significantly different cooling needs.

[0215] In some examples, the controller can be arranged to provide a power saving algorithm that switches to powering the electric heating element solely via AC power if DC power is unavailable (e.g., if the battery charge is low or zero). The controller can be programmed to ensure that a minimum threshold of DC capacity is always available, for example, to allow high-power heating from a cold start, or to conserve the AC grid during very busy periods (when it is truly needed). A user can selectively enable or disable this feature by sending instructions to the controller via a user interface. In some examples, the minimum threshold of DC capacity can be 5% of the total battery capacity to be backed up.

[0216] In some examples, the present invention provides a space heater that can safely provide modular power packs that can be easily replaced within the confines of the heater housing. The capacity of the power pack is large enough so that it can provide a heating load for a typical domestic living room space via a DC power source in a reasonable time (e.g., at least 5 minutes or at least 10 minutes). A power pack of this size can be safely placed within the confines of the housing using the thermal shielding described above. Because the battery charger cooling mechanism may often operate at different times than the controller and battery cooling mechanism, it can include or contain a cooling mechanism that is separate or different from the controller and battery cooling mechanism.

[0217] In some cases, there may be multiple cooling mechanisms, for example, at least one cooling mechanism associated with the controller and / or other heater power electronics, at least one cooling mechanism associated with the battery, and at least one cooling mechanism associated with the battery charger.

[0218] In some examples, the cooling system can be a passive cooling system (instead of or in addition to the aforementioned cooling systems) arranged to transfer heat from the component to be cooled (e.g., the heater electronics or the DC power supply or the battery charger or any combination thereof). The passive cooling system may not include a flowing fluid. The passive cooling system may include a heat sink (e.g., an aluminum block with natural convection fins for dissipating heat to the environment). The passive cooling system may include a relatively large thermal mass, such as a heater housing.

[0219] Space heaters are typically portable, but can also be mounted on a surface, such as a room wall. This is usually achieved by using a suitable mounting bracket. Depending on the type of space heater, it may be desirable to leave a gap between the wall and the mounting surface to allow for safe airflow.

[0220] In some examples, the heater includes an AC port for powering other devices, and / or a USB port or wireless charging for powering other devices.

[0221] In some examples, the heater may be arranged to operate in a camping mode - it may be useful to run the fan version described above, or any of the other examples, as a portable camping tent heater.

[0222] In many examples, the present invention can provide a significant power boost compared to electric heaters using only AC power, for example, a 50Wh DC power pack used with the present invention allows an additional 500W of operation for 6 minutes (for example, a total output of 3490W in the UK using a standard power socket, or 2900W in the US (which would otherwise be limited as discussed above)). A larger capacity power pack will provide longer runtimes combined with higher boost power levels.

[0223] In some examples, any one or more of the controller; the AC power adapter; the DC-AC converter; and the AC-DC converter are located close to the first electric heating arrangement (e.g., within 50 cm, or within 15 cm, or within 10 cm, or within 2 cm). This reduces the amount of wiring required and simplifies assembly. It also reduces the likelihood of electrical interference, thereby providing more efficient operation.

[0224] In any example, the controller of the space heater may include a hardware thermostat controller and, optionally, another graphical user interface thermostat controller.

Claims

1. An electric space heater comprising: a first electric heating arrangement arranged to be powered by an AC power source and a DC power source; and A controller is arranged to control the distribution of power from the DC power supply and the AC power supply to the first heating arrangement.

2. The space heater according to claim 1, wherein The DC power source has a capacity of at least 0.05 kWh, optionally at least 0.1 kWh, optionally at least 0.25 kWh.

3. The space heater according to claim 1 or 2, wherein: The AC power source comprises a mains AC power source, and the combined peak power of the DC power source and the AC power source is at least 25%, optionally at least 50%, and optionally at least 100% greater than the peak power of the mains AC power source alone.

4. A space heater according to any preceding claim, further comprising the DC power supply and optionally a DC power supply charging mechanism arranged to recharge the DC power supply.

5. A space heater according to any one of the preceding claims, further comprising a cooling system arranged to provide cooling to any one or more of: the controller; the DC power supply; and the DC power supply charging mechanism.

6. A space heater according to any one of the preceding claims, wherein In use, the first electric heating arrangement is located above the DC power supply, the controller, and optionally when referenced to claim 4 the first electric heating arrangement is located above the DC power supply charging mechanism.

7. A space heater according to any one of the preceding claims, comprising a thermal break or thermal shield located between the DC power supply and the first electric heating element, and optionally located between one or more of: the controller; the DC power supply charging mechanism; or the controller and the DC power supply charging mechanism; and the first electric heating element.

8. A space heater according to any one of the preceding claims, wherein The AC power supply comprises an AC power adapter arranged to interface with an external AC power source, such as mains AC power.

9. A space heater according to any one of the preceding claims, comprising: a DC-AC converter located between the DC power supply and the first electric heating arrangement, such that the first electric heating arrangement is arranged to receive only AC power from the AC power supply, the DC power supply, or both; or an AC-DC converter located between the AC power source and the first electric heating arrangement such that the first electric heating arrangement is arranged to receive only DC power from the AC power source, the DC power source, or both.

10. A space heater according to any one of the preceding claims, wherein The controller is arranged to control a combination of outputs from the AC power source and the DC power source.

11. A space heater according to any one of the preceding claims, wherein The controller is arranged to vary the ratio of AC and DC power to the first electric heating arrangement, optionally by controlling switching between an AC only power mode and a DC only power mode.

12. A space heater according to any one of the preceding claims, wherein The controller is arranged to: when boosted heating is required, powering the first electric heating arrangement using only the DC power supply, and when stable, continuous heating is required, powering the first electric heating arrangement using only the AC power supply; or When it is determined that the local AC grid may be overloaded, using the DC power supply to power the first electric heating arrangement; or both.

13. A space heater according to any one of the preceding claims, wherein The first electric heating arrangement comprises a single electric heating element arranged to be powered by both an AC power source and a DC power source.

14. A space heater according to any one of the preceding claims, wherein The first electric heating arrangement comprises a plurality of electric heating elements, for example a first electric heating element arranged to be powered only by the AC power supply and a second electric heating element arranged to be powered only by the DC power supply.

15. A space heater according to any one of the preceding claims, further comprising a heater housing, wherein The heater housing is arranged to accommodate the first electric heating arrangement, and optionally, the heater housing has an inlet and an outlet, atmospheric air entering the heater housing through the inlet and heated air leaving the heater housing through the outlet, and further optionally, wherein the inlet is located in a bottom surface of the heater housing, the space heater further comprising a base arranged to raise the inlet from a surface on which the space heater is placed in use, optionally, the base being part of the heater housing.

16. A space heater according to claim 15, further comprising a guide arrangement arranged to guide air along a desired flow path between the inlet and the outlet, and optionally wherein, The guiding device includes a fan system, and optionally, the fan system is arranged to guide air from outside the heater housing into the heater housing and to guide the air towards the DC power supply, and the fan system is further arranged to guide the air towards the first electric heating arrangement after the air passes through the DC power supply and then towards the outlet.

17. A space heater according to claim 15 or claim 16, wherein The heater housing is arranged to accommodate any one or more of: the DC power supply; the controller; the cooling system; the DC power supply charging mechanism; the AC power adapter; the DC-AC converter; the AC-DC converter; and the fan system.

18. A space heater according to any one of claims 15 to 17, comprising an elongate electric heater, wherein The DC power supply, the controller, the first electric heating arrangement and the outlet are arranged in a straight line, and optionally, the fan system is also arranged in a straight line with the DC power supply, the first electric heating arrangement and the outlet.

19. A space heater according to any one of the preceding claims, comprising a modular space heater, the modular space heater comprising a base module arranged to interface with the AC power supply, a middle section module arranged to accommodate the DC power supply and a top module arranged to accommodate the first electric heating arrangement, the base module, the middle section module and the top module being arranged to be connected together via any one or more of the following to form the heater housing: a slot fit; a clip fit; a friction fit; a screw fit; a bolt fit.

20. The space heater of claim 19, wherein: The bottom module is arranged to be directly connected to the top module and also directly connected to the middle section module; The top module is arranged to be directly connected to the roof module and also directly connected to the mid section module; and The middle section module is arranged to be connected to the bottom module and the top module; Such that in a first usage configuration, all three modules can be used together to provide heating via the AC power source and the DC power source, and in a second usage configuration, the bottom module and the top module can be used together without the middle section module to provide heating via only the AC power source.

21. A space heater according to any one of the preceding claims, further comprising a radiator housing filled with a heating fluid (such as oil), wherein The first electric heating arrangement is located, in use, inside the radiator housing and close to the bottom, and is arranged to heat the heating fluid.

22. The space heater of claim 21, wherein The DC power supply is located below the first electric heating arrangement when in use.

23. A space heater according to claim 21 or claim 22, wherein The DC power supply is located external to the radiator housing, optionally located below or to the side of the radiator housing, and optionally wherein the DC power supply comprises an attachable battery pack arranged to attach to the radiator housing to form the space heater.

24. A space heater according to any one of claims 21 to 23, wherein The radiator housing is arranged to be attached to the heater housing and optionally, in use, to be located above the heater housing.

25. A method of operating a space heater according to any preceding claim, the method comprising controlling the power distribution from the DC power supply and the AC power supply to the first heating arrangement, and optionally controlling the power distribution by only the DC power supply or the AC power supply at any given moment.

Images