Entrance shelter

Abstract

An outside unit 601 of an air source heat pump transfers heat energy between air outside a building and air inside the building. The outside unit contains an evaporator 603 of the air source heat pump

Description

TECHNICAL FIELD

[0001] The present invention relates to an entrance shelter. The entrance shelter is attached or attachable to a building over a building entrance. The entrance shelter comprises an overhead portion configured or arranged in use to provide shelter or shade to a person stood outside the building entrance. According to embodiments of the present invention, the entrance shelter additionally houses or supports parts of a building ventilation, heating, or cooling system. The present invention also relates to a building construction method incorporating the entrance shelter and a method of operating the entrance shelter. BACKGROUND

[0002] Frequently, some form of shelter is provided for a person stood outside of an entrance to a building. An entrance to a building is typically an exterior door, but may instead be any other accessway such as an open passage. The term “entrance shelter” should be interpreted broadly to encompass any form of structure so long as it includes at least an overhead portion to provide shelter to a person from rain or other inclement weather. The term “entrance shelter” is used in this document in a generic sense to include synonyms such as canopy, door canopy, porch, entrance roof, awning, portico, or vestibule. In addition to an overhead portion, an entrance shelter may include one or more support legs, side panels or walls. An entrance shelter may be partially or fully enclosed to provide further shelter to a person stood outside of the entrance to the building.

[0003] Conventionally, an entrance shelter for a house is integrally formed or structurally incorporated into the main structure of the house, and is often referred to as a porch. However, more recently, some entrance shelters have been provided as a product or module that is separately constructed and provided substantially complete before being attached to a wall of a house to extend over a door. This may be a retrofit product, or it may be sourced and fitted at the time of first constructing a building (though after the wall itself is substantially complete). Such an entrance shelter product may be a relatively lightweight structure to be attached to the building wall, for instance with some form of metal bracket affixed to the wall structure. Such an entrance shelter may be substantially formed as an elongate box that in use protrudes generally horizontally from the wall above the door, though one or more legs or sidewalls may be provided that are also attached to the building wall and may extend to ground level. Where legs or sidewalls are provided, they may also provide support to the overhead portion. While such an entrance shelter product may in principle be subsequently removed from the building, more commonly the entrance shelter is installed and kept in place for its lifespan.

[0004] Often an entrance shelter, including one that is formed as a product or module that is attached or attachable to a building, may support an exterior light. However, an entrance shelter does not normally include any further functionality.

[0005] It is an aim of certain examples of the present invention to solve, mitigate or obviate, at least partly, at least one of the problems and / or disadvantages associated with the prior art. Certain examples aim to provide at least one of the advantages described below. BRIEF SUMMARY OF THE INVENTION

[0006] According to a first aspect of the present invention there is provided an entrance shelter attached or attachable to a building over a building entrance, wherein the entrance shelter houses or supports an inlet to or an outlet from a building ventilation system.

[0007] An advantage of certain embodiments of the present invention is that because the entrance shelter is external to the structure of the building, it is readily accessible to tradespeople who need to service or repair ventilation or heating components supported by or housed within the entrance shelter. Accordingly, there is no need to enter the building or disturb the building occupants. Where the entrance shelter is attached to a house that is rented to tenants, this has the benefit that the landlord can arrange for tradespeople to perform maintenance on the house ventilation or heating system without having to arrange access to the house in advance.

[0008] The entrance shelter may further comprise a filter arranged such that in use air drawn into the building ventilation system through the inlet is filtered. The filter may be releasably attached to the inlet such that it is removable from the entrance shelter.

[0009] The entrance shelter may house or support an inlet to and an outlet from the building ventilation system.

[0010] The entrance shelter may further house or support at least one component of an air source heat pump. The at least one component of an air source heat pump may comprise an evaporator configured to absorb heat from the ambient environment.

[0011] The outlet from the building ventilation system may be arranged such that in use air discharged from the building through the outlet is directed across or through the evaporator.

[0012] An advantage of embodiments of the present invention in which the outlet from a building ventilation system is discharged across or through an evaporator of an air source heat pump is that residual building heat in the discharged air will be warmer than the ambient temperature outside of the building. During winter conditions this flow of warm air provides frost protection to the evaporator. This may remove or reduce the need for a frost protection heating element or the need to periodically run the heat pump in reverse to warm the evaporator.

[0013] The evaporator may be housed partially or fully within the entrance shelter; or the evaporator may be partially or fully exposed to the exterior of the entrance shelter. The entrance shelter may further comprise a fan configured to direct ambient air across or through the evaporator.

[0014] The evaporator may form part or the whole of an exterior weatherproof surface of the entrance shelter.

[0015] An advantage of embodiments of the present invention in which the evaporator of an air source heat pump forms part or the whole of an exterior weatherproof surface of the entrance shelter is that a lighter weight and reduced cost entrance shelter incorporating an evaporator can be provided as there is no requirement for a roofing layer in addition to the evaporator.

[0016] The at least one component of an air source heat pump may comprise or further comprise: a compressor; a pump; or a condensate drain.

[0017] The outlet may be configured to direct air discharged from the building across the building entrance to form an air curtain.

[0018] An advantage of embodiments of the present invention in which the outlet from a building ventilation system forms an air curtain across the building entrance, particularly a door, is that when the door is opened the air curtain forms a barrier between the environments inside and outside of the building. This can prevent the movement of air, heat, and airborne contaminants through the doorway when the door is open, while allowing people to move freely through the doorway. The air curtain can also reduce building energy consumption by reducing the mixing of outdoor and indoor air, which requires additional building heating or cooling to address.

[0019] The entrance shelter may further house or support an evaporator of an air source heat pump, the evaporator being configured to absorb heat from the ambient environment; and wherein in use air from the building may be selectively discharged across the building entrance to form an air curtain or across or through the evaporator.

[0020] Air may be selectively discharged across the building entrance to form an air curtain in response to a sensor signal indicating that the door is open.

[0021] The entrance shelter may comprise an overhead portion configured or arranged in use to provide shelter or shade to a person located outside the building entrance. The overhead portion: may be supported at least in part by being attached in use to the building; or may be supported at least in part by one or more legs, walls, or side structures.

[0022] The entrance shelter may further comprise a photovoltaic panel disposed on or forming part of an exterior surface.

[0023] The entrance shelter may house or support at least one: environment sensor; camera; or light.

[0024] The entrance shelter may define a housing, the housing including at least one openable section for maintenance access to components and systems housed therein.

[0025] According to a second aspect of the present invention there is provided a building comprising: an entrance; and an entrance shelter as described above and attached to the building over the entrance.

[0026] The building may include a building ventilation system having an inlet duct coupled to an inlet housed or supported by the entrance shelter. The building ventilation system may comprise a Mechanical Ventilation with Heat Recovery, MVHR, system.

[0027] According to a third aspect of the present invention there is provided a building construction method comprising: attaching an entrance shelter to a wall of a building over a building entrance, wherein the entrance shelter houses or supports an inlet to or an outlet from a building ventilation system; and coupling the inlet or the outlet to ducting within the building for the building ventilation system.

[0028] According to a fourth aspect of the present invention there is provided a method of operating an entrance shelter attached to a building over a building entrance, wherein the entrance shelter houses or supports an inlet to or an outlet from a building ventilation system, the method comprising: drawing fresh air into the building ventilation system through the inlet; or discharging stale air from the building ventilation system through the outlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Examples of the invention are further described hereinafter with reference to the accompanying drawings, in which: Figure 1 illustrates in a perspective view an entrance shelter attached to a building over a building entrance and incorporating an inlet to a ventilation system according to an embodiment of the present invention; Figure 2 illustrates in a cross-section plan view an entrance shelter attached to a building and incorporating an inlet and an outlet to a building ventilation system according to an embodiment of the present invention; Figure 3 illustrates in a cross-section plan view an entrance shelter attachable to a building and incorporating an inlet and an outlet to a building ventilation system and an evaporator of an air source heat pump according to an embodiment of the present invention; Figure 4 illustrates in a perspective view an entrance shelter attachable to a building in which an evaporator of an air source heat pump forms part of the exterior of the entrance shelter according to an embodiment of the present invention; Figure 5 illustrates in a cross-section plan view an entrance shelter attachable to a building and incorporating an inlet and an outlet to a building ventilation system, an evaporator of an air source heat pump and an air curtain outlet according to an embodiment of the present invention; and Figure 6 illustrates an air source heat pump exterior unit connected to an outlet of a building ventilation system. DETAILED DESCRIPTION

[0030] Referring first to figure 1, this illustrates an entrance shelter 101 attached to the wall 102 of a building 103 over a building entrance 104, in this case an exterior door 104. The building 103 may suitably be a house but the present invention is not restricted to this. The wall 102 may be formed in any conventional manner. The entrance shelter 101 is formed as a separate product or module prior to delivery to site and attached to the wall 102 for instance through the use of brackets that are first attached to the wall 102 and then concealed within the body of the entrance shelter 101, however the present invention is not restricted to any particular attachment mechanism.

[0031] The entrance shelter 101 is illustrated as an elongate “box” structure that extends from the building 103 along a first axis indicated by arrow 105 and is positioned above the entrance 104. The entrance shelter 101 extends to either side of the entrance 104 along a second axis indicated by arrow 106. It will be understood that the particular size and shape of the entrance shelter along the first and second axes 105, 106 may vary so long as at least part of the entrance shelter 101 is positioned over the entrance 104 along a third, depth axis indicated by arrow 107.

[0032] An upper surface 108 of the entrance shelter 101 is configured to provide rain protection. The upper surface 108 may be horizontal or it may have a slope to shed rainwater (and a rainwater drain may be provided, not illustrated).

[0033] The entrance shelter of figure 1 and all subsequent entrance shelter figures may include one or more side wall, such as is shown in figure 4. In some embodiments the entrance shelter may be configured as a porch comprising a roof, two side walls and a front wall including a door. That is, the entrance shelter is open on a backside but when attached to the wall of building about a door the wall of the building and the entrance shelter define a fully enclosed space having a first door formed in the wall of the building and opening into the building and a second door that leads out of the porch to the outside of the building. Such an enclosed entrance shelter or porch may still be provided as a product or module that is sourced in a substantially complete form and attached to a wall of a building either during construction of the building or during retrofit conversion.

[0034] As described below, the enclosed shelter incorporates elements of a building ventilation system. Embodiments of the present invention are not limited to any particular form of building ventilation system. It will be understood that in the context of the present document the term ventilation system is intended to encompass building systems including one or more element of heating and air conditioning as well as ventilation. A Heating, Ventilation and Air Conditioning, HVAC, system remains a ventilation system.

[0035] One particular type of HVAC system (or a component or sub-system within a HVAC system) is a Mechanical Ventilation with Heat Recovery (MVHR) system. MVHR is a type of mechanical ventilation system used in residential and commercial buildings to provide fresh air while recovering the heat from the outgoing air. Extracted stale air from the building passes through a first duct network to a heat exchanger which transfers the heat from the outgoing air to the incoming fresh air drawn into the building through an inlet which is then distributed back into the building through a separate duct network. This process helps to maintain a comfortable indoor temperature while reducing energy consumption and carbon emissions. The MVHR system also helps to improve indoor air quality by continuously exchanging stale air with fresh air, reducing the build-up of pollutants and excess moisture.

[0036] The enclosed shelter may incorporate elements of an Air Source Heat Pump, ASHP. The elements of these systems incorporated into, housed, or supported by the entrance shelter may come preinstalled such that all remains for the entrance shelter installer is to attach the entrance shelter to the building and make the appropriate connections to ducting inside the building, and where required an electrical power supply. The entrance shelter may incorporate appropriate seals so that when attached to the building a weathertight seal is formed between the entrance shelter and the wall and particularly about any ducting from the building ventilation or heating system or from the entrance shelter that extends through the wall. A fully enclosed porch that may be attached to a building provides significant benefits to the occupants of the building: it provides a break between the outdoors and the indoors for storage of shoes, coats, and parcels. It provides a thermal break, and an airlock, which reduces loss of heat from a building through an exterior door.

[0037] The entrance shelter may be alternatively referred to as a module, a shelter module, or a canopy module that is attached to a building or a building module. It may be supplied from a factory substantially complete and ready for attachment to the building and coupling to a building ventilation or heating system as required. Thus, may be referred to as a module incorporating one or more elements of a ventilation system such as an MVHR system or one or more elements of a heating system such as an ASHP. For an enclosed entrance shelter as discussed above, this may be considered to be a module including a first door that when coupled to a building about a second door forms an enclosed module with two doors.

[0038] Figure 1 further shows that the entrance shelter 101 includes an inlet 109 to a building ventilation system. Furthermore, the inlet 109 includes a filter 110 to filter air drawn into the building ventilation system. The filter 110 services to reduce the ingress of contaminants into the building ventilation system. It some examples the filter 110 may be a relatively coarse filter designed to remove the largest contaminants and the building ventilation system may include a second, finer inlet filter, functioning as the main system filter, and located within the building, for instance in a building plant room. For instance, for an MVHR system, the main system filter may be designed to filter out particulate matter larger than 2.5 pm. Filter 110 installed in the entrance shelter 101 may be selected to filter out larger contaminants, for instance larger than 5 pm or larger than 10 pm (or larger still). Filter 110 may serve to prolong the lifespan of the main system filter and reduce the pressure drop across the main system filter during its lifespan by reducing the passage of coarse contaminants to the main system filter that might otherwise cause a blockage.

[0039] Advantageously, the filter 110 may be removable from the inlet 109 for servicing or replacement. Any suitable attachment mechanism for providing a removable filter 110 may be used. For instance, the inlet 109 may include a filter cover that is hinged and openable to access the filter 110. By providing the filter at a location outside of the building, it may be easily accessed by a maintenance technician.

[0040] Inlet 109 and filter 110 may be provided on the underside of the entrance shelter 101, as illustrated. Advantageously, this prevents rain ingress. However, the present invention is not limited to any particular position of inlet 109 and filter 110 upon the entrance shelter 101, so long as it opens to the outside of the building and is accessible for maintenance. In particular, where the entrance shelter 101 includes one or more sidewall or other element (not illustrated), the inlet 109 and filter 110 may be provided at that location. The particular illustrated dimensions and shape of the inlet 109 should not be considered to be limiting. Rather, the minimum size of the inlet 109 will be dictated by the specifications of the building ventilation system, particularly throughput of fresh air, the required level of filtering and the maximum pressure drop permitted across filter 110 (which determines its dimensions).

[0041] Inside the entrance shelter 101 (not shown in figure 1) air drawn through the filter 110 passes into an inlet duct that in turn passes through a hole formed in the wall 102 and connects to the building ventilation system (with either the inlet duct within the entrance shelter 101 extending through the wall to couple to a building duct or a building duct extending through the wall 102 to couple to the entrance shelter inlet duct).

[0042] Turning now to figure 2, this illustrates in a cross-section plan view an entrance shelter 201 attached to a wall 102 of a building 103 and incorporating an inlet 204 and an outlet 205 both coupled to a building ventilation system 206 according to an embodiment of the present invention. The view of figure 2 is a cross-section in a horizontal plane when the entrance shelter 201 is attached to a building in a similar fashion to figure 1. The ventilation system 206 is illustrated as an MVHR system in which fresh air drawn into the building 103 passes through an inlet duct 207 to a heat exchanger 208 where it is warmed by stale air drawn out of the building 103 through an outlet duct 209. However, the present invention is not limited to an entrance shelter 201 connected to an MVHR system: inlet 204 and outlet 205 may connect to any form of ventilation system. The inlet 204 is shown provided with a filter 210, which may be as described above for the entrance shelter of figure 1. Outlet 205 has no filter illustrated, but may be provided with a filter or grill to prevent animals entering the outlet duct 209.

[0043] As for figure 1, the inlet 204 and outlet 205 may suitably be provided on the underside of the entrance shelter 201 (not evident from the cross-section) to avoid rain ingress. However, the location, shape and dimensions illustrated for the inlet 204 and the outlet 205 should not be considered to be limiting. In some situations, it is desirable for the inlet 204 and the outlet 205 to be spaced apart so as to avoid recirculation of stale air into the building.

[0044] Turning now to figure 3, this illustrates in a cross-section plan view an entrance shelter 301 attachable to a building and incorporating an inlet 302 (which may or may not include a filter) and an outlet 303 to a building ventilation system and an evaporator 304 of an air source heat pump according to an embodiment of the present invention. More generally, the entrance shelter 301 houses or supports at least one component of an Air Source Heat Pump, ASHP, however the particular example of housing an evaporator 304 is illustrated.

[0045] An ASHP is a heating and cooling system that transfers heat energy between the air outside a building and the air inside a building. In a heating mode it works by using a refrigerant to absorb heat from the outdoor air, and then transferring that heat inside to heat the building. In a cooling mode the process is reversed, with the refrigerant absorbing heat from the indoor air and releasing it into the outdoor. Normally key components of an ASHP are contained in an outdoor unit attached to a wall of the building or supported on the ground proximal to the building and a corresponding indoor unit (plus appropriate ducting to connect the two). In particular, the outside unit normally contains a compressor and an evaporator. The compressor compresses a refrigerant and pumps the compressed refrigerant through the system. In a heating mode the refrigerant expands and evaporates as it passes through the evaporator in the outside unit, and the refrigerant absorbs latent heat from the air surrounding the outdoor unit. The evaporator thus comprises a heat exchanger that transfers heat from the ambient environment to the refrigerant (or the reverse if the system is run in reverse in a cooling mode). A fan may blow air over the evaporator to accelerate this process. The hot refrigerant then passes through a heat exchanger (normally located in the inside unit), where it transfers heat from the refrigerant to a separate air circuit, which circulated heated air within the building. The cooled refrigerant is returned to the compressor in a closed loop. The refrigerant circuit and the air circuit are thus separate from one another, but exchange heat through the heat exchanger.

[0046] The heated air is distributed throughout the building via a duct system or through individual room units. Air from cooler portions of the building is drawn in using a pump and fed to the heat exchanger to be heated. Alternatively, the refrigerant may transfer heat to a water circuit within the heat exchanger, with that water being fed to a hot water cylinder for supply hot water to a tap or to a heating appliance such as a radiator or underfloor heating pipe. When used for heating, other liquids may be used in place of water.

[0047] The present inventors have recognised that an entrance shelter that is attached or attachable to a wall of a building proximal to a building entrance comprises a convenient location for mounting part or the whole of the components of the ASHP (optionally alongside another outdoor unit for housing the remaining components). Figure 3 illustrates an ASHP evaporator 304 being housed within or support upon the entrance shelter 301 to absorb heat from the ambient environment outside the building. However, in other embodiments, alternative components of the ASHP such as a compressor, a refrigerant pump, a heat exchanger, a condensate drain, or any other component normally found in an ASHP outside unit may be incorporated into the entrance shelter as well as or in place of the evaporator 304. Figure 3 is a cross-section plan view of an entrance shelter comprising an overhead “box” of the form illustrated in figure 1 and housing the evaporator. However, where the entrance shelter is formed with one or more side walls, or in an enclosed form as discussed above, then it will be apparent to the skilled person that substantially more storage volume may be provided to house further ASHP components. For instance, where a side wall is provided, it may be relatively deep in order to accommodate a compressor of an ASHP. Furthermore, an entrance shelter incorporating at least one wall that rests on the ground may be better able to support the weight of all of the components of an ASHP compared to an overhead entrance shelter that is attached to (for instance, bolted to) a wall of a house.

[0048] The evaporator 304 may be wholly contained within the entrance shelter 301. Alternatively, the evaporator 304 may be partially or fully exposed to the exterior of the entrance shelter 301. A fan (not illustrated) may be configured to direct ambient air across or through the evaporator in a conventional fashion to increase the transfer of latent heat from the air to the refrigerant. Furthermore, figure 3 illustrates that a ventilation system (for instance, an MVHR system) stale outlet 303 is configured to direct air discharged from the building across or through the evaporator 304. Advantageously, this means that any residual heat from the inside of the building (not transferred to incoming fresh air in a heat exchanger) may be transferred to the refrigerant passing through the evaporator 304. Additionally, this warm, stale heat may act to prevent frost build up on the evaporator 304 during cold weather. This may mean that there is no need to provide an electrical frost protection circuit or periodically run the ASHP in reverse to warm the evaporator 304.

[0049] According to some examples of the present invention, the functions of an MVHR and an ASHP may be combined such that the ASHP heat exchanger transfers heat from the refrigerant circuit to the fresh air inlet of the MVHR (as well as, for instance downstream of) the heat exchange from stale air to fresh air within the MVHR heat exchanger. This may be in place of the ASHP heat exchanger heating air that is recirculated within the building.

[0050] Figure 3 further shows a refrigerant inlet 305 and a refrigeration outlet 306 for the evaporator 304. It will be understood that these will couple to the rest of the refrigerant circuit, including the compressor, which may be provided in another portion of the entrance shelter 301, in a separate ASHP outside unit or possibly within the building, for instance in a plant room.

[0051] Turning now to figure 4, this illustrates an entrance shelter 401 according to a further embodiment of the present invention in which an ASHP evaporator 402 forms part or the whole of an exterior weatherproof surface of the entrance shelter 401. In particular, the evaporator 402 of figure 4 is formed as a substantially or fully sealed unit and forms part or the whole of an upper, roof part 403 of the entrance shelter 401. As illustrated, the evaporator 402 may form the entire roof of the entrance shelter 401 and be configured to seal to the wall of the building when the entrance shelter 401 is attached. However, the evaporator may form less than the whole of the roof of the entrance shelter 401. As described for figure 3, an outlet from a building ventilation system (not illustrated) may discharge air across or through the evaporator 402 to provide frost protection and to make use of residual building air. Similarly, a fan (not illustrated) may be provided to increase the volume of ambient air about the building 103 flowing across or through the evaporator 402.

[0052] Figure 4 further illustrates the entrance shelter 401 having at least one side wall 404 in addition to the roof part 401. The side wall 404 is shown in partial cross-section and houses further components of the ASHP. In particular, the side wall 404 houses the compressor 405 which is coupled to the evaporator 402 by refrigerant ducts 406, 407. The side wall 404 further includes refrigerant ducts 408, 409 configured to couple to an inside ASHP unit when the entrance shelter 401 is attached to a building. An advantage of housing a compressor 405 and other portions of the refrigeration circuit in the entrance shelter, external to the building is that in the event of a refrigerant leak less risk is posed to building occupants. An advantage of housing or supporting the evaporator 402 in or on the entrance shelter is that commonly condensate forms on an evaporator and a condensate drain is required. The condensate drain may be incorporated into a rainwater drain for rainwater that lands on the overhead portion of the entrance shelter.

[0053] Referring now to figure 5, this illustrates an entrance shelter 501 attached to a wall 102 of a building 103. The entrance shelter 501 includes an inlet 502 configured to connect to a building ventilation system (not illustrated), the inlet 502 including a filter 503 as previously described. Furthermore, the shelter 501 includes an ASHP evaporator 504 (which may be internally housed as described for figure 3 or which may form a roof of the shelter 501 as described for figure 4).

[0054] The evaporator 504 is coupled to a stale air outlet of a building ventilation system via a valve 505 to function as described above for figures 3 and 4. However, the valve 505 is configured to direct the flow of stale air either across or through the evaporator 504 or through an air curtain 506. An air curtain is a device that creates a barrier of air to separate two different environments, typically on either side of an open doorway. It works by blowing a high-velocity stream of air downwards across the width of the doorway, which creates a "curtain" of moving air that acts as a barrier between the inside and outside of the building or room.

[0055] Air curtain 506 comprises an elongate nozzle mounted horizontally above a building exterior door. The air curtain 506 directs a stream of air across the door to prevent the movement of air, temperature, and airborne contaminants through the doorway when the door is open, while allowing people to move freely between the two spaces. Air curtains are commonly used in commercial and industrial settings, such as retail stores, restaurants, and manufacturing facilities, to maintain comfortable indoor temperatures and keep out insects, dust, fumes, and other outdoor contaminants. They can also help to reduce energy consumption by preventing the loss of heated or cooled air when doors are frequently opened and closed. However, they have not previously been commonly used for homes.

[0056] According to an embodiment of the present invention the valve 505 is controlled by a sensor (not illustrated) that detects whether the door is open. The sensor may be of any generally known type, for instance a Hall effect sensor. The valve 505 may be controlled to direct stale air to the evaporator 504 when the door is closed and to direct stale air to the air curtain 506 when the door is open.

[0057] Entrance shelters according to embodiments of the present invention may further include one or more photovoltaic panels disposed on or forming part of an exterior surface. That is, a photovoltaic panel may be configured to form a weatherproof surface of the entrance shelter to remove the need for an additional weatherproof layer. The photovoltaic panel may be formed over an ASHP evaporator, or they may be provided on separate portions of the entrance shelter.

[0058] Entrance shelters according to embodiments of the present invention may further house or support additional equipment normally provided on the exterior of a building, for instance an environment sensor, security camera or exterior light.

[0059] As described above, entrance shelters according to embodiments of the present invention contain equipment that may require periodic access for maintenance. Accordingly, the entrance shelter may be formed as a housing including at least one openable section for maintenance access to components and systems housed therein.

[0060] Turning now to figure 6, an outside unit 601 of an ASHP is illustrated, positioned against a wall 102 of a building. The housing of the outside unit 601 is shown partially cutaway. The ASHP outside unit 601 includes an evaporator 603 that is arranged to be coupled to an outlet 604 from a building ventilation system (not illustrated) in order to provide frost protection to the evaporator and to extract residual heat from stale air exhausted from the building (as described above in connection with figure 3). The outside unit 601 further includes additional ASHP components, for instance a compressor 605. Advantageously, the benefits of combining an ASHP evaporator with the outlet from a building ventilation system is not restricted to the evaporator being incorporated into an entrance shelter.

[0061] Throughout this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other components, integers, orO steps. Throughout this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise. Throughout this specification, the term “about” is used to provide flexibility to a range endpoint by providing that a given value may be “a little above” or “a little below” the endpoint. The degree of flexibility of this term can be dictated by the particular variable and can be determined based on experience and the associated description herein.

[0062] Features, integers, or characteristics described in conjunction with a particular aspect or example of the invention are to be understood to be applicable to any other aspect or example described herein unless incompatible therewith. All of the features disclosed in this specification, and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The invention is not restricted to the details of any foregoing examples. The invention extends to any novel feature or combination of features disclosed in this specification. It will also be appreciated that, throughout this specification, language in the general form of “X for Y” (where Y is some action, activity or step and X is some means for carrying out that action, activity, or step) encompasses means X adapted or arranged specifically, but not exclusively, to do Y.

[0063] Each feature disclosed in this specification may be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0064] The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

Claims

1. An outside unit of an air source heat pump configured to transfer heat energy between air outside a building and air inside the building, in which the outside unit contains an evaporator of the air source heat pump, and the evaporator is configured to be coupled to an outlet from a building ventilation system so that, in use, air discharged from the building through the outlet is directed across or through the evaporator.

2. An outside unit as claimed in claim 1, in which the outside unit is configured to be positioned outside against a wall of the building.

3. An outside unit as claimed in either of claims 1 or 2, in which the outside unit comprises at least one further component of the air source heat pump, selected from the group comprising: a compressor; a pump; a heat exchanger; and a condensate drain.

4. An outside unit as claimed in any preceding claim, comprising a refrigerant inlet and a refrigerant outlet for the evaporator.

5. A building ventilation system comprising:an outlet configured to discharge stale air from a building; andan air source heat pump configured to transfer heat energy between air outside the building and air inside the building, the air source heat pump comprising an outside unit containing an evaporator;in which the evaporator is coupled to the outlet so that, in use, stale air discharged from the building through the outlet is directed across or through the evaporator.

6. A building ventilation system as claimed in claim 5, comprising an inlet configured to draw fresh air into the building, and in which the air source heat pump comprises a heat exchanger which transfers heat to or from the fresh air in the fresh air inlet.

7. A building ventilation system as claimed in claim 6, in which the outside unit contains the heat exchanger.

8. A building ventilation system as claimed in any one of claims 5 to 7, in which the building ventilation system is a Mechanical Ventilation with Heat Recovery (MVHR) system.

9. A building ventilation system as claimed in any one of claims 5 to 8, in which the outside unit is an outside unit according to any of claims 2 to 4.

10. A building comprising a building ventilation system, in which the building ventilation5 system comprises:an outlet configured to discharge stale air from the building; andan air source heat pump configured to transfer heat energy between air outside the building and air inside the building, the air source heat pump comprising an outside unit containing an evaporator;10 in which the evaporator is coupled to the outlet so that stale air discharged from thebuilding through the outlet is directed across or through the evaporator.

11. A building as claimed in claim 10, in which the building ventilation system is a building ventilation system according to any of claims 6 to 9.15

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