Heating / cooling device for offices

Abstract

The invention relates to a heating / cooling device for offices, in particular for offices having multiple workstations, wherein the heating / cooling device has at least one first heating / cooling element (1) per room, which can be connected to a central heating / cooling circuit in the building and is provided with a respective associated control unit (2) with a thermostat. A first heating / cooling element (1) which can be associated with a workstation is provided for each workstation in the room, wherein the first heating / cooling element (1) comprises two heating / cooling registers (3, 4) which can be connected to the central heating / cooling circuit and which are arranged parallel to one another, wherein a heating / cooling register (3) is arranged horizontally in the floor region below a desktop (5) and the second heating / cooling register (4) is arranged at a parallel distance from same directly below the desktop (5) or within the desktop (5).

Description

HEATING / COOLING EQUIPMENT FOR OFFICE SPACES Technical field

[0001] The invention relates to a heating / cooling device for office spaces, in particular for offices with multiple workstations, wherein the heating / cooling device has at least one first heating / cooling element per room, which can be connected to a central heating / cooling circuit present in the building, and which has an associated control unit with thermostat. State of the art

[0002] The Covid-19 pandemic has significantly impacted the design and use of office spaces. In most European countries, flexible workspaces will be a key feature of future offices. Working from home will increase, and the purpose of the traditional office will change, with office spaces increasingly being used only two to three days a week.

[0003] For employees in the office of the future, a better indoor climate will be a key motivator for coming to work. This means that for employers, offices should be flexible, ecological, and promote health, and for owners, buildings should offer an appealing design and, above all, energy-saving and environmentally friendly building technology.

[0004] Furthermore, the EU directive on the overall energy efficiency of office buildings was updated in 2020, and accordingly, the heating energy demand (HWB) for buildings had to be adjusted as follows. For passive houses, an HWB of 10 to 15 W per m² per year now applies, for low-energy houses an HWB of 15 to 25 W per m² per year, and for existing buildings an HWB of 25-50 W per m² per year.

[0005] Existing heating systems typically only offer the option of heating or cooling the entire room to a specific temperature. Especially in open-plan offices or office spaces with multiple workstations, this is inefficient when the space is only partially occupied by varying numbers of employees, leading to significant energy losses over time.

[0006] Even with all workplaces fully occupied, the problem already exists that the heating or cooling needs of individual employees can differ greatly, and therefore comfort is reduced for at least some of the employees if only a single temperature range can be achieved.

[0007] Existing heating and cooling systems operate using conventional radiators, chilled ceiling panels, activated building components, or air recirculation systems. In all cases, however, the focus is on temperature control for individual rooms, not smaller areas such as a single workstation. The current occupancy of an office space is also typically only considered, if at all, through time-based controls. Systems with longer response times, such as activated building components, often cannot react quickly enough to rapidly changing occupancy patterns at individual workstations, rendering such controls impractical. Description of the invention

[0008] The object of the present invention is to create a heating / cooling system that meets the aforementioned requirements for the heating demand (HWB) and enables significant energy savings, while simultaneously increasing comfort for employees present in the office spaces. By creating individually adjustable comfort zones, it should be possible to set each workstation to the preferred temperature range. Furthermore, particularly in cases of irregular use of varying numbers of workstations, for example in an open-plan office, energy savings should be achieved by not heating or cooling individual unused workstations.

[0009] This problem is solved according to the invention by providing a first heating / cooling element for each workstation in the room, wherein the first heating / cooling element comprises two heating / cooling registers that can be connected to the central heating / cooling circuit and are arranged parallel to each other. One heating / cooling register is arranged horizontally in the floor area below a desktop, and the second heating / cooling register is arranged parallel to and spaced apart from it, directly below or within the desktop. The arrangement of heating / cooling elements that can be assigned to individual workstations and are connected to the building's central heating / cooling circuit makes it possible, for example, to maintain a base temperature of only 12 to 14°C in a suitable office space during heating operation, even in winter. When using control units with a presence sensor, e.g.,An infrared sensor increases the room temperature to approximately 16 to 18°C, or, in suitable passive houses, maintains it at this temperature range with low energy consumption. The lower base room temperature is possible without compromising comfort, as the heating / cooling device according to the invention creates a small heated or cooled comfort zone at each individual workstation.

[0010] These new heating / cooling elements can be set by the user to a temperature between 25 and 40°C. The human body, positioned at the desk, benefits from radiant heat exchange and can cool down optimally in cooler room air of approximately 16 to 18°C, resulting in increased comfort near the heating / cooling element, similar to a tiled stove.

[0011] In cooling mode, the surface temperature of the heating / cooling element is approximately 20°C, ensuring comfort even at an ambient room temperature of 28°C. The heating / cooling device according to the invention improves the indoor climate, promotes health, and offers energy-saving and environmentally friendly building technology with energy cost savings of approximately 30% to 40%, depending on the operating mode.

[0012] An additional preferred feature is that the first heating / cooling element, together with the heating / cooling register that can be arranged in the floor area, includes an electric heating element that can be switched on via a separate control system, serving as additional underfloor heating. When a workstation is put into operation, it can be advantageous to provide an additional electrically operated heating element, at least in the area of ​​the underfloor heating of the heating / cooling element, which reacts quickly during the start-up phase and rapidly establishes a comfortable temperature for the user. As soon as the heating / cooling registers, which are supplied via the central heating / cooling circuit, have reached their full capacity, the electric heating element can be switched off again. This makes the device according to the invention even more responsive.

[0013] According to one possible embodiment, a further preferred feature is that the first heating / cooling element is designed as a retrofittable module comprising the two heating / cooling registers, the control unit, and height-adjustable supports connecting the two heating / cooling registers. This allows the first heating / cooling element to be placed under a conventional desk and fixed in this position by means of the height-adjustable supports. This offers a simple way to retrofit existing office buildings with existing furniture with the heating / cooling device according to the invention. The respective heating / cooling element can correspond to a standard workstation width and be clamped under each desk using the height-adjustable supports. The individual heating / cooling elements are then connected to the central heating / cooling circuit via suitable flexible hoses.For this purpose, there are known, easy-to-install, tight plug connections available in the state of the art.

[0014] Another advantageous feature is that the retrofittable module includes at least one additional vertical heating / cooling register on the side facing away from the user when installed under a desk. Depending on the workstation and building type, this allows for the easy creation of an additional heating surface.

[0015] In some embodiments, it is also preferred that an electric heating element, switchable via a separate control, is provided on at least one of the vertical side walls of the retrofittable module. This can be an alternative arrangement of the fast-responding electric heating element if an arrangement in the floor area is not desired. In other embodiments, the arrangement of the vertical electric heating element can also be in addition to one arranged in the floor area, in order to create a comfort zone particularly quickly.

[0016] According to an alternative preferred embodiment, the first heating / cooling element is an integral part of a desk, with the upper heating / cooling register located directly below or within the desktop. When planning a new office space, the heating / cooling element can also be integrated directly into the desk, allowing for larger desk surfaces or custom dimensions. The number and arrangement of the individual heating / cooling elements can be optimally considered during the initial planning of the workstations in each office space.

[0017] Furthermore, a preferred feature is that, in buildings that do not meet the passive house standard of 10 to 15 W per m² per year, at least one second heating / cooling element is provided in addition to the first heating / cooling element. This second element takes the form of a heating / cooling register arranged vertically in a wall element, preferably for one or two workstations per room, with the wall element being suitable as a room divider or for placement on a building wall. In the case of a passive house building, an office space can be operated with just one heating / cooling element per workstation. Due to the good thermal insulation, the heating / cooling output provided by the heating / cooling elements is sufficient to maintain the temperature of the entire room and to create appropriate individual comfort zones in the workstation areas.In buildings that meet the HWB value for low-energy houses, it is advisable to provide at least one additional heating / cooling element per office room, designed as a wall element, which either improves the comfort zone around one or more workstations or provides for the basic temperature control of the entire room.

[0018] Another preferred feature is that the second heating / cooling element, designed as a wall panel, incorporates additional functionalities, such as sound insulation, light sources, connections and / or switches for electricity or network technology, and the like. For office spaces, the wall panels can also include additional functionalities, such as sound insulation, light sources, or the housing of other equipment like sockets, switches, or similar devices.

[0019] In addition to or as an alternative to the second heating / cooling element, another preferred feature is that, in buildings that do not meet the passive house standard of 10 to 15 W per m² per year, at least a third heating / cooling element, in the form of a suspended ceiling panel, is provided in addition to the first heating / cooling elements. In low-energy houses, a second or third heating / cooling element can be used in addition to the existing first heating / cooling elements, thereby achieving sufficient heating / cooling capacity depending on the room size. In existing buildings with a higher heating demand, it may also be necessary to install second and third heating / cooling elements in the relevant rooms, in addition to the first heating / cooling elements provided per workstation, in order to meet the required heating / cooling demand.

[0020] According to a further preferred feature, the control unit is provided with a presence sensor to detect a user at the respective workstation, enabling the heating / cooling system to be automatically switched on or off depending on the user's presence. The actual energy savings in practice are expected to be significantly increased because the heating / cooling system is only in operation when an employee is present, which can be detected, for example, by a presence sensor, allowing the individual heating / cooling elements to be switched on or off automatically. Such a presence sensor could, for example, be an infrared sensor.

[0021] Finally, another preferred feature is that the control unit has a network interface, allowing the respective heating / cooling system to be switched on and off via a central server, for example, through a corresponding workplace booking platform. Alternatively or additionally, the control unit can have a network interface, enabling individual workstations to be controlled via a network. This allows, for example, individual workstations to be controlled via booking platforms. An employee can, for instance, reserve a workstation at a specific time using an app, and the heating / cooling system can be switched on via the network interface in good time before the start of the reserved work period, so that the workstation has already reached the desired temperature when the user arrives. Brief description of the drawings

[0022] The invention will now be described in greater detail with reference to an exemplary embodiment and the accompanying figures. Figure 1 shows a schematic perspective view of a first and second heating / cooling element, Figure 2 a schematic sectional view of a second heating / cooling element, Figure 3 a schematic side view of a possible embodiment of a first heating / cooling element arranged under a conventional desk, Figure 4 a schematic sectional view of a room arrangement with first and second heating / cooling elements assigned to each workstation, Figure 5 a schematic sectional view of a room arrangement with first and third heating / cooling elements assigned to each workstation, Figure 6 a diagram of the comfort rating according to Fanger for a simulated office room with conventional room heating and with the two variants according to Figures 4 and 5, and Figure 6.7 a schematic perspective view of a further embodiment of a first heating / cooling element as a module that can be retrofitted under a conventional desk. Way(s) to implement the invention

[0023] Figure 1 schematically shows a workstation with a first heating / cooling element 1 integrated into the desk according to the heating / cooling device of the invention. The corresponding first heating / cooling element 1 integrated into the desk has heating / cooling registers 3, 4 that can be controlled separately by control units 2. One heating / cooling register 3 is arranged in the floor area below the desktop 5, and a further heating / cooling register 4 is integrated into the desktop 5 in this example. The heating / cooling registers 3, 4 can be connected to a conventional central heating / cooling circuit, which, for example, uses water as the medium for heat or cold transfer.In the area of ​​the floor-mounted heating / cooling register 3, an additional electric heating element 7 is also arranged. This element can be controlled via a separate control unit 6 and allows the user to quickly warm the workspace, at least during heating operation, until the somewhat slower-reacting heating / cooling registers 3 and 4 also reach temperature and take over the heating function, after which the electric heating element 7 switches off again. In buildings that meet passive house standards and where only heating is required, electric heating elements can also be used exclusively. These can then be located in the floor area, in the area of ​​the desktop, or, if necessary, additionally as wall elements. This particularly simple design does not require connections to any existing central heating / cooling circuit but can be connected to any electrical outlet.

[0024] A second heating / cooling element 9 is designed as a wall element 10 and is also assigned to the workstation. A heating / cooling register 11 is also housed in the wall element 10. Furthermore, additional functions can be accommodated in the wall element 10, such as a sound insulation device 12 or connections 13, for example, for electricity or network technology. A possible layered structure of the second heating / cooling element 9 is shown, for example, in Fig. 2.

[0025] Figure 3 shows another possible embodiment of a first heating / cooling element 1, which can be retrofitted to any conventional desk. The two heating / cooling registers 3 and 4 are spaced apart from each other by height-adjustable supports 8. The corresponding heating / cooling element 1 can thus be placed under any desk, and the height-adjustable supports 8 press the upper heating / cooling register 4 against the desk surface 5 from below. This secures the heating / cooling element 1 in its position.

[0026] Figures 4 and 5 show different exemplary room layouts, each with two workstations. These rooms were also used for simulation calculations to determine energy consumption and the thermal comfort of the employees. Figure 4 shows an arrangement with first and second heating / cooling elements 9, and Figure 5 shows an arrangement with first and third heating / cooling elements 14.

[0027] The building simulation is based on an ideal, fictitious office space within a building. The simulation model represents a typical new office building, allowing the investigated parameters to be considered in isolation as much as possible. Therefore, a simplified zone within a building in Vienna was chosen for the simulation. Parameters unrelated to the varying heating / cooling system were excluded as far as possible.

[0028] The key points of the simulation are listed below: Climate data set: Vienna Hohe Warte Location: Vienna - inner city, 200 m above the Adriatic Sea. Wind profile: City center Target temperature Microclimate Workplace Heating (operational): 22°C Cooling (operational): 26°C Office space 15.6 m²: 4.0 x 3.9 x 2.7 m [L x W x H] (clear dimensions) with 2 workstations on the 4th floor: Floor +12.0 m above ground one wall exposed to outside air facing southwest remaining walls and ceilings adiabatic (no heat flow) Window in the southwest exterior wall: 2.05 x 1.65 m [W x H] with radiation-dependent controlled sun protection g tot = 0.15 (external venetian blind) Air tightness of building envelope: n 50 = 1.0 1 / h Hygienically necessary air exchange according to ÖNORM B 8110-5: n L= 1.05 1 / h [22.1 m³ / h. Person] via central air handling unit with 80% heat recovery and supply air temperature: Heating: 16 °C Cooling: 24 °C Air currents within the building or other openings within the building zone are disregarded. Internal loads each weekday 08:00 to 17:00 Lighting: 20 W / workplace Persons: 1 person / workplace Energy consumption: Met 1.2 (sedentary activity) Clothing clo 0.75 ±0.25 (shirt, trousers or short-sleeved shirt / sweater) Equipment 80 W / workplace (computer, monitors, telephone, etc.) Comfort assessment according to Fanger with ÖNORM EN ISO 7730 Typical windows / component assemblies in solid construction No thermal bridges No hot water demand No building services (only energy supplied to / from the room is considered) None Shading from other buildings

[0029] The simulations performed essentially involve a qualitative comparison of a conventionally conditioned office space (V0) with the variants shown in Fig. 4 (V1) and Fig. 5 (V2). The respective difference between the simulation and the reference variant yields the energy savings. Furthermore, thermal comfort at the workplace was evaluated using Fanger's comfort parameters.

[0030] To establish a reference (V0) for all further qualitative comparisons, a standard office space with conventional conditioning using heating and cooling elements in the form of radiators for heating and suspended chilled ceilings for cooling was modeled. The entire room is conditioned to 22°C for heating and 26°C for cooling. For V1 and V2, the room air was conditioned to 18°C ​​for heating and 28°C for cooling.

[0031] It has been shown that the use of the heating / cooling device according to the invention significantly reduces both the heating and cooling loads required for conditioning the work area in extreme cases. Specifically, the heating load is approximately 30% lower than in a conventionally conditioned room (V0). The cooling load can even be reduced by 37 to 43%. The annual cooling load estimate is based on 500 full-load cooling hours.

[0032] Table 1 Energy consumption [kWh / a] Variant 0 Variant 1 Variant 2 Heating 1268992.4 Cooling 248136152

[0033] Fanger's comfort rating, using the parameters PMV (expected average comfort level) and PPD (expected average dissatisfaction rate), is a normative assessment method for the thermal comfort of individuals within a zone. Essentially, it concerns the thermal equilibrium (heat balance) between the human body and its environment. Parameters such as physical activity, clothing, and environmental conditions like air temperature, radiant temperature, air velocity, and humidity are considered in the assessment. The comfort rating is also influenced by asymmetrical radiant temperatures (e.g., cold / warm floor), drafts, and vertical air temperature differences.Fanger's comfort rating is an internationally standardized method for assessing the thermal comfort of individuals in a room exposed to a moderate ambient climate. The rating applies to healthy, average individuals in an indoor climate designed to promote comfort. Comfort is a subjective perception and therefore strongly influenced by each individual's ethnic, national, or geographical background. Age, physical limitations, and psychological state can also significantly impact comfort. Individual regulation of the local air temperature, or the mean radiant temperature, can help to balance the relatively large differences between individual requirements and thus lead to greater satisfaction.

[0034] The results of the comfort assessment for the simulation are summarized in Fig. 6. The use of the heating and cooling system according to the invention increases the comfort of every individual working in the office. This is reflected in the improved comfort classes according to Fanger (V1, V2) compared to a conventionally conditioned office (V0), both in heating and cooling modes. Particularly in cooling mode, which is often the decisive factor for typical office buildings, there is a significantly lower number of dissatisfied individuals (PPD) compared to a conventionally conditioned office. The different PPD values ​​reflect the desired balance between the goal of minimizing dissatisfaction and what is achievable with the available technology. The four classes apply to zones in which all individuals are exposed to the same ambient climate.It is advantageous if each individual can be provided with an individual control option for the ambient climate, as is possible with the heating / cooling elements according to the invention for each workstation. Individual control of the local air temperature and the mean radiant temperature can help to compensate for the relatively large differences between individual requirements and thus lead to fewer dissatisfied employees.

[0035] In the simulation calculations, target values ​​of 22°C for heating and 26°C for cooling were defined. Due to the existing individual control options for each workstation, it can be assumed that the highest possible level of comfort can be achieved for each individual. The standardized assessment according to Fanger also takes into account solar radiation and the resulting energy input to each person. To achieve Fanger comfort class I, the radiant temperatures would also have to be almost continuously adjustable due to solar radiation; this is usually only achievable with disproportionate technical effort.

[0036] Surprisingly, it has thus been demonstrated that the heating / cooling device according to the invention achieves significant energy savings of approximately 30% in heating mode and even over 40% in cooling mode, while simultaneously increasing the comfort of occupants at the respective workstations. The individual first heating / cooling elements are relatively inexpensive to manufacture, which quickly offsets any slightly higher initial costs compared to conventional radiators through the energy savings. According to one of the possible embodiments, the first heating / cooling elements can also be easily retrofitted to existing office furniture. Together with second and / or third heating / cooling elements, improved energy consumption and comfort can be achieved not only in passive houses, but also in low-energy houses or existing buildings.

[0037] Figure 7 shows another embodiment of a first heating / cooling element 1 as a retrofittable module for a conventional desk. To minimize the design freedom of interior designers and to maximize the choice of different desk manufacturers, it is advantageous if the first heating / cooling element can be arranged as an independent module under any desk. The embodiment shown in Figure 7 schematically depicts a somewhat more complex structure than that in Figure 3. In addition to the two horizontally arranged heating / cooling registers 3 and 4, a further vertical heating / cooling register 17 is provided on the side surface facing away from the user when installed under a desk. A side wall 16 is located on the left side wall, on which the height-adjustable supports 8 are arranged in the lower area, and which also serves as a mounting for the control unit 2.On the right side surface there is another electric heating element 15 which can be switched on via its own control, which can be provided as an alternative or in addition to an electric heating element located in the floor area and thus enables a particularly rapid establishment of the comfort zone when the device is started.

Claims

Heating / cooling device for office spaces, in particular for offices with multiple workstations, wherein the heating / cooling device has at least one first heating / cooling element (1) per room, which can be connected to a central heating / cooling circuit present in the building, and which has an associated control unit (2) with thermostat, characterized in that a first heating / cooling element (1) attributable to the workstation is provided for each workstation present in the room, wherein the first heating / cooling element (1) comprises two heating / cooling registers (3, 4) connectable to the central heating / cooling circuit, which are arranged parallel to each other, wherein one heating / cooling register (3) is arranged horizontally in the floor area below a desktop (5) and the second heating / cooling register (4) is arranged parallel to it, spaced apart, directly below the desktop (5) or within the desktop (5). Heating / cooling device for office rooms according to claim 1, characterized in that the first heating / cooling element (1) together with the heating / cooling register (3) which can be arranged in the floor area has an electric heating element (7) which can be switched on via a separate control (6) as additional underfloor heating. Heating / cooling device for office spaces according to claim 1 or 2, characterized in that the first heating / cooling element (1) is designed as a retrofittable module which comprises the two heating / cooling registers (3,4), the control unit (2) and height-adjustable supports (8) connecting the two heating / cooling registers (3,4), so that the first heating / cooling element (1) can be placed below a conventional desk and fixed in this position by means of the height-adjustable supports (8). Heating / cooling device for office rooms according to claim 3, characterized in that at least one further vertical heating / cooling register (17) is provided in the retrofittable module on the side surface facing away from the user when installed under a desk. Heating / cooling device for office rooms according to claim 3 or 4, characterized in that an electric heating element (15) which can be switched on via a separate control is provided on at least one of the vertical side walls of the retrofittable module. Heating / cooling device for office rooms according to claim 1 or 2, characterized in that the first heating / cooling element (1) is an integral part of a desk, wherein the upper heating / cooling register (4) is arranged directly below the desktop (5) or within the desktop (5). Heating / cooling device for office rooms according to one of claims 1 to 6, characterized in that in buildings which do not meet the passive house standard of 10 to 15 W per m² per year, in addition to the first heating / cooling elements (1), at least one second heating / cooling element (9) in the form of a heating / cooling register (11) arranged vertically in a wall element (10) is provided per room, preferably per one or two workstations, wherein the wall element (10) can be placed as a room divider or on a building wall. Heating / cooling device for office rooms according to claim 7, characterized in that the second heating / cooling element (9) designed as a wall element (10) has additional functionalities, such as sound insulation devices (12), light sources, connections (13) and / or switches for electricity or network technology and the like. Heating / cooling device for office rooms according to one of claims 1 to 8, characterized in that in buildings which do not meet the passive house standard of 10 to 15 W per m² per year, in addition to the first heating / cooling elements (1) at least a third heating / cooling element (14) in the form of a heating / cooling ceiling panel which can be mounted at a distance from the ceiling is provided. Heating / cooling device for office rooms according to one of claims 1 to 9, characterized in that the control unit (2) has a presence sensor for detecting a user at the respective workstation, whereby the heating / cooling device can be automatically switched on or off depending on the presence of a user. Heating / cooling device for office spaces according to one of claims 1 to 10, characterized in that the control unit (2) has a network interface, so that the respective heating / cooling device can be switched on or off via a central server, for example via a corresponding workplace booking platform.

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