DE68912813T2 - Method and device for supplying conditioned air. - Google Patents

Description

The present invention relates to a method of supplying conditioned air to one or more locations on a particular floor or level of an apartment building or block of flats by means of air conditioning equipment to which circulated air is supplied and a cabinet-type supply air connection device which is arranged on the floor of the apartment floor or level or which can be arranged in the vicinity of the floor.

The invention also relates to a cabinet-like connection device for air supply and in particular to a device of the type set out in the preamble of claim 6.

Known air conditioning and air supply methods and apparatus of the aforementioned type cause draughts and generate noise, especially when the supply air connection device is provided with separate fans or blowers. Furthermore, the methods and apparatus have a relatively low ventilation efficiency and consequently the occupied areas of a room or a place served by such a device are not free from contamination and it is necessary to supply the air conditioning system with air that is relatively clean, which further increases the load on the system. Exhaust air from the place served by the system, on the other hand, has a relatively low degree of contamination.

Further disadvantages associated with the known device and method are limited flexibility in that the Supply air connection devices cannot be easily arranged in desired positions on the apartment floor (storey) or the room to be served by the device. The structure of supply air connection devices of existing systems is also relatively complicated, which has further increased the cost of these systems.

A method and a device of the type disclosed in the preamble of claim 1 and 6 respectively is disclosed in DE-A-29 38 702 (LTG).

Further examples of the current state of the art are described in "VVS & Energi", No. 1, January 1986, Stockholm. Sweden. Bengt Bergqvist and Engelbrekt Isfält; "KLIMATSYSTEM AND BYGGNAD I SAMVERKAN", pages 71-75, especially page 74: "Deplacerance inblasning"; VVS & Energi", No. 9, September 1983, Stockholm. Sweden. Ragnar Järmyr: "Deplacerande ventilation", pages 29-31, and catalogue 84/85 "BAHCO Ventilation", July 1984, Enköping, Sweden; "System Floormaster", pages 17:1.1-17:1.4 and "Tilluftsdon GKF". Pages 13:5.1-13:5.4.

DE-A-24 07 448 (Kessler & Luch) and DE-A-27 54 699 (Lind) are further documents of interest in this context.

An object of the present invention is to eliminate the disadvantages of the above-mentioned and other known systems and to provide an improved air supply system which, among other things, enables air flow and air temperature to be controlled separately and effectively in individual supply air connection devices. thereby achieving high ventilation efficiency and high temperature efficiency.

A further object is to provide an air supply system that creates an improved environment and climate, particularly in occupied areas of a room served by the system according to the invention, while at the same time supporting the operation of the air conditioning system and improving its efficiency.

These objects are achieved by the method according to the invention, the main characterizing features of which are set out in the characterizing part of claim 1.

Because the air is supplied to the place served by the system at a relatively low floor at the same time that the circulating air is supplied to the air conditioning system at a level below that at which the exhaust air leaves that place, the air present in the place is stratified in various degrees of pollution, thereby mainly improving the climate of the occupied zone of the place. Polluted air converges or collects at a high level close to the ceiling of the room served by the system and is withdrawn from that place through the exhaust air connection devices installed at that level. The air present in the center of the occupied zone or area of that place has a relatively high degree of purity and circulating air of this type is supplied to the air conditioning system, thereby reducing the load on the system to a considerable extent.

The air cleaned in the system is supplied to the room located immediately below the floor where the air is effectively mixed with directly supplied fresh air. The supply air connection devices located as desired in the location served by the system will ensure that this mixture of fresh air and clean, treated air is supplied to the room or location at a low level therein, in the absence of draughts and while being fully regulated, which in turn assists in the aforementioned stratification of the air in the room.

In practice, it is preferred that the supply air is supplied at a level lower than 1.2 m, i.e. at a level of about 1 m above the floor level, and that the circulation air is supplied to the system at a level lower than 2.2 m, preferably at a level of about 2 m above the floor level.

One or more exhaust air connection devices are preferably arranged at a higher position in the place or room served by the air conditioning system, preferably near the ceiling of the room.

As previously indicated, when the method of the invention is applied, fresh air is mixed with the treated air in the space located under the floor of the room, hereinafter referred to as the floor cavity. In this regard, a substantially constant pressure is maintained in the floor cavity, preferably by controlling the speed of a fan or blower comprising the air conditioning system. The floor cavity has a pressure sensor mounted therein which is connected to the fan motor via a control device so as to ensure that the floor cavity will remain at a set pressure level. In this way it is ensured that all supply air connection devices in the room or location being served are supplied with air of a constant predetermined pressure which in turn will ensure that the devices operate efficiently and reliably and in a predetermined manner.

If the temperature in the room or location should fall during the winter months, this will be registered by the thermostat or thermostats, which will control the throttle valve of the air supply terminals so as to reduce the flow of supply air to a level that is consistent with this. Each supply air terminal may be fitted with a heater so that if low ambient temperatures are continuously registered, despite the throttle valve settings, the supply air can be heated before it is supplied to the room. In this case, the throttle valves will have the reverse function, i.e. a greater heating requirement will result in a corresponding further opening of the valves.

In practice, the mixture of treated air in the air conditioning system and fresh air is fed to the supply air connection device via a centrally located soundproof duct and, after being diverted by 180º near a throttle valve in the region of the upper part of the duct, is caused to leave the device via holes or slots provided in one or more sides of the device, without causing the pressure in the device to rise.

This method of supplying air to the supply air terminals and the area surrounding them will effectively dampen noise and will also ensure that the air leaving a supply air terminal has a low swirl, i.e. creates virtually no draught, even in the immediate vicinity of the device.

This means in practice that a supply air connection device of the type described above can be arranged adjacent to working positions in the room or place served by the system, i.e. adjacent to a desk. In fact, the supply air devices can be given such a shape that they themselves form part of the actual work station, i.e. in practice have the same height as the desk and form a work surface or some other surface adjacent to a desk surface.

Particular advantages are achieved if the electrical cables, telephone cables, etc., leading to various equipment in the room or location served by the system are located in the floor cavity. According to a preferred embodiment of the invention, these cables are received from the floor cavity through a space in the respective supply air connection devices specifically provided for this purpose.

This allows cables to be pulled directly to or in close proximity to tele-computer equipment and the like arranged on a desk, thus avoiding the problem of tangled cables which is normal in most cable arrangements of this type.

The fan of the air conditioning system is preferably located in the floor cavity or in its immediate vicinity. This allows the treated air to be effectively directed to the floor cavity without creating a drop in air pressure as a result of further deflection of the air flow.

The floor cavity in question is preferably covered with floor panels, boards or similar according to a modular system to which the outlet part of the air conditioning unit and the connecting parts of the connection device for the supply air are also adapted. Thus, the outlet part of this unit can be given an area which in cross section corresponds to the area of one or a certain number of floor panels, which also applies to the connecting supports or connection bases of the connection devices for the air supply.

When installing an air supply connection device, it is therefore only necessary to remove one or a required number of floor panels at the appropriate location in a room and subsequently connect and seal the device. This allows the system considerable flexibility and enables modifications to be easily carried out, e.g. when position changes are to be made in the system of a location, a room or an apartment floor in a block of apartments.

The invention also relates to a connection device for air supply which can be arranged next to or on the floor surface of a room or a place, the main characterizing features of these devices being set out in the characterizing part of claim 6.

Advantages of the invention will become clear from the following description of selected embodiments of the invention.

The description is given with reference to the attached drawing.

Fig. 1 is a perspective view showing part of a floor or storey of an office block and showing a number of offices supplied with air which has been conditioned by means of the air conditioning system according to the invention;

Fig. 2 is a plan view of a portion of the floor or storey shown in Fig. 1 and illustrates the supply of fresh air and the mixing of the air with the air conditioned according to the invention:

Fig. 3 is a sectional view of an air conditioning unit forming part of the air supply system:

Fig. 4 shows a perspective view of a cabinet-like connection device for air supply according to the invention:

Fig. 5 is a sectional view taken along the line V-V in Fig. 4: and

Fig. 6 is a sectional view taken along the line VI-VI in Fig. 5.

Fig. 1 shows a part of a floor or storey of an office block comprising a number of offices divided by walls 1. Centrally arranged on the illustrated floor of the office block is an air conditioning unit 2 which has a vertical extension of approximately 2 m from the surface level of the floor.

Circulated air is introduced into the unit 2 via its top, where it is filtered and cooled before being directed to a cavity 3 beneath the floor 4 of the room or location. The floor 4 comprises a plurality of square floor panels 5. In the case of the embodiment shown, the area of each floor panel corresponds to the cross-sectional area of the unit 2, which means that only one panel is removed at the location where the unit 2 is to be located.

The floor panels may optionally be divided into sections, one or more of which correspond to the cross-sectional area of the support members or connection bases on which the air supply connection devices used are mounted, these devices being generally designated 10 in the drawing. An air supply connection device according to the invention will be described in more detail hereinafter. The arrows 7 drawn in the floor cavity indicate that the conditioned air leaving the unit 2 will spread throughout the cavity 3.

As shown in Fig. 2, fresh air is also supplied to the floor cavity 3 via a fresh air duct 8 perforated with holes 9 and located adjacent to the unit 2 so that air leaving the unit is mixed with the fresh air in the duct 8. The cutaway area in Fig. 2 illustrates the approximate size of the mixing zone thus achieved.

When it is desired to supply conditioned air to a selected area in a room or a location on the floor or storey served by the system, e.g. a work area around a desk 20, for example a part of a floor panel 5 is removed and an air supply connection device of the type illustrated in Fig. 4 is fitted over the space thus exposed.

The illustrated connector device 10 comprises a main body portion 11, a base or connector base 12 and a top cover 13 which may be located level with the top of the desk 20 and thus may itself serve as the desk top or desk work surface.

As shown in Figs. 5 and 6, the device 10 also has a centrally arranged air supply duct 14 which is lined with sound-absorbing material and which widens in the region of the base 12 to form a lower connecting part 14a.

The device 10 further comprises two side plates 16 perforated with outlet holes 15 and a front plate 17 also perforated with outlet holes. The outlet holes 15 are arranged in vertical rows and in an outward direction from each of these rows is arranged a vertically extending plate 18 with inwardly bent end portions. This arrangement ensures that the air is supplied to the environment gently, with a low swirl, and that the air is well mixed with the ambient room air.

In the device 10, a throttle valve 21 is arranged, which has two curved parts 21a and 21b and which is connected via a temperature sensor 22 is controlled in such a way that the amount of air supplied to the environment is regulated. If the prevailing room temperature is low, the setting of the valve is adjusted accordingly so as to provide a minimum air flow.

The valve parts 21a and 21b divert the incoming air from the channel 14 by 180º. The inner upper corners of the air supply connection device are significantly curved in order to achieve a deflection of the air flow with a substantial absence of turbulence.

The valve parts 21a and 21b direct the main part of the incoming air flow towards the two opposite vertical side plates 16, whereas a smaller part of the air flow is removed through the holes 15 arranged in the front plate 17.

The fourth side panel 23 of the cabinet-like connection device for the air supply consists of a vertically movable wall element which defines a space 24 in the device. This space is intended for the accommodation of telephone cables and electrical cables 24. which extend to the workplace in question. Such a cable arrangement 24, which is pulled through the floor cavity 3, is shown in Fig. 1.

The space 24 in the device 10 is also defined on its inwardly disposed side by a partition 25 adjacent the inlet channel 14. The main part of the device 10 is vertically movable relative to the connection base or base 12. This allows the device to be given a desired vertical extension within certain limits, for example such that the upper surface or the plate 13 of the device will coincide with the level of the working surface of the desk 10. The main part of the device can be removably attached to the base 12 by means of pins 27 which pass through holes provided in the base.

A nozzle 30, which can distribute the supply air evenly along the surfaces of the device, is fitted into each of the bores 15.

The reference numeral 31 identifies an electric heater for heating the supply air when necessary or desired, e.g. during the winter months. When the heater is in use, the aforementioned valve 21 operates in reverse, i.e. the valve is opened further at lower temperatures.

The air conditioning unit 2 shown in Fig. 3 is equipped with an air filter 35 which effects filtering of the supplied circulated air, the filtered air being subsequently treated in a heating/cooling battery. A variable speed fan 37 effects moving the air to the cavity under the floor 4. The pressure prevailing in the floor cavity 3 is detected by means of a sensor not shown. When a tendency towards a lower pressure in the floor cavity is detected, a pulse is sent to a control device which in response increases the speed of the fan so as to maintain the pressure at a predetermined level.

It can be seen from Fig. 1 that the supply air connection devices also supply air at a level below 1 m, whereas the circulating air is supplied to the unit 2 at a level approximately twice this height above floor level, ie at a level of about 2 m. Polluted air will collect in an area slightly below the ceiling of the room and will be ventilated therefrom via an exhaust air connection device 38. The system assumes that the various places or rooms on the floor or storey of the building served by the system will communicate with each other, eg via suitable grilles arranged above the corresponding doors.

The high quality of air achieved by applying the method according to the invention is due to the fact that the circulated air is introduced into the unit 2 at a level located in the occupied zone of a room or place, whereas polluted or contaminated air, which collects immediately under the ceiling of the room, is expelled through exhaust air connection devices located at a corresponding level.

In practice, the pressure of the air in the floor cavity 3 can be of the order of 20 to 30 Pa. Excessively high pressure in the cavity can cause sealing problems in the floor above. It can also lead to problematic noise levels.

However, the configuration of the supply air connection device shown provides an advantageous solution to the type of problem described above.

Claims (11)

1. A method for supplying conditioned air to one or more locations (1) on the floor or storey of a multi-storey building by means of an air conditioning unit (2) to which circulated air is supplied and also by means of cabinet-like connection devices for supply air arranged on or near the floor (5) of this location (1), the outlet opening of the air conditioning unit (2) being connected to the floor (5) in such a way that conditioned air is supplied under pressure to a cavity (3) under the floor (5). whereby holes for an auxiliary part (14a) connecting to the supply air connection devices (10) are provided in the floor (5) at desired locations on the floor or storey of the building, and the air supply connection devices (10) are mounted and sealed above the holes, the air connection devices (10) providing a low-swirl displacement air flow at a level lower than that at which exhaust air is expelled from that location, characterized by mixing fresh air with the treated air in the cavity (3) and maintaining a substantially constant pressure in the cavity (3), supplying the low-swirl displacement air flow to that location via the supply air connection devices (10) at a level lower than that at which the circulated air is supplied to the air conditioning unit (2); and regulating the displacement air flow in response to the temperature in individual supply air ports (10). 2. Method according to claim 1, characterized in that the displacement air flow is supplied at a level below 1.2 m, preferably below about 1 m above the floor of the storey: and in that the circulated air is supplied to the unit (2) at a level below 2.2 m, preferably at a level of about 2 m above the level of the floor of the storey. 3. Method according to claim 1 or 2, characterized by maintaining a substantially constant pressure in the cavity by regulating the speed of a fan (37) which cooperates with the air conditioning unit (2). 4. Method according to claim 3, characterized in that the air which is conditioned in the unit (2) and mixed with the fresh air is supplied to the supply air connection devices (10) via a centrally arranged, soundproofed duct (14); that the air is diverted through an angle of 180º in the region of a throttle valve (21) which is arranged next to the upper region of the duct: and that the diverted air flow is caused to be discharged through the holes (15) or slots provided in one or more of the side plates (16) of the device, without being subject to an increase in pressure. 5. Method according to one of claims 1 to 4, when electrical cables, telephone cables and the like are pulled through the cavity (3) under the floor (4), characterized in that corresponding cables are received through the floor via a space (24) provided in corresponding connection devices (10) for supply air at this end. 6. Supply air connection device for positioning on or near a floor (4) of a place or room, the device being intended to cooperate with an air conditioning unit (2) to which circulated air is supplied and whose outlet opening is intended for connection to the floor so that conditioned air is supplied under pressure to a cavity (3) under the floor, the supply air connection device comprising: a) a main body (16) with a connection base (12) and a top plate (13); b) an air supply channel (14) provided in the device ; c) at least one side plate (16) provided with air outlet holes (15) or slots; and d) a lower connecting part (14a) connected to the connection base (12) and/or the air supply duct (14) and which is intended for connection to an opening in the floor so that conditioned air can be supplied at pressure from the cavity (3) under the floor (4) to the supply air connection device, which is designed to provide a low-swirl displacement air flow at a level lower than the level at which exhaust air is discharged from the location or room, characterized in that on the supply channel (14), which is preferably arranged centrally in the device (10), at the top of which is mounted thermostatically controlled valve means (21) for controlling the amount of air which, except for a minimum flow, is diverted by 180º to a space formed between the duct (14) and the plate (16) provided with outlet holes (15) or slots: and in that the air supply connection means is designed to provide a low swirl displacement air flow at a level below the level at which the circulated air is introduced into the air conditioning unit (2). 7. Device according to claim 6, characterized in that the valve device (21) has two curved parts (21a, 21b) and that the valve device is intended to control the air flow to two opposite perforated side plates (16) of the device (10). 8. Device according to claim 7, characterized in that between the two perforated side plates (16) a third perforated side plate (17) is arranged through which air is supplied. 9. Device according to one of claims 6 to 8, characterized in that a side plate (23) of the device (10) is movable or has a movable portion and forms a defining wall of a space (24) in the device (10), the space being intended for accommodating electrical cables, telephone cables or the like, which are taken up from the cavity (3) under the floor. 10. Device according to one of claims 6 to 9, wherein the holes (15) or slots in the side plate or the side plates (16; 17) are arranged in vertical rows, characterized in that, pointing slightly outwardly from each such row of holes or slots, there is arranged a vertically extending plate (18) having end portions bent inwardly towards the side plates in a manner to redirect the outgoing supply air stream and create swirling flows or turbulence therein. 11. Device according to one of claims 6 to 10, characterized in that the main part of the device can be moved to different height positions with respect to the connection base (12) and is removably fixed in the positions.