FI101826B - Equipment for distributing supply air to air-conditioned rooms - Google Patents

Description

101826

Equipment for distributing supply air to air-conditioned rooms

The invention relates to an apparatus for distributing supply air, in particular to large and / or medium-height ventilated rooms, which apparatus comprises a plurality of elongate air distribution devices mounted in a substantially parallel and substantially horizontal position.

In large and / or tall buildings, it is known to use powerful air jets to bring the supply air into the room and / or to control the air flows in the room. Such air distribution systems are described, for example, in FI 66484, FI 773852, DE 2919793, FI 962774 and EP 085428.

15 The advantages of the above systems include the low need for air conditioning ducts, which leads to low investment costs. The powerful air jet extends far as it is in the free space, so there is no need to transport air in the ducts close to the object to be ventilated.

Particularly preferred is a system in which air jets are used, for example, to transport the main air flow brought to the other side of a large factory hall to the entire area of the hall and to distribute it to the living area. A powerful air jet pulls the so-called. by means of the induction phenomenon, the ambient air, according to him, is considerably greater than the air flow of the jet itself as it leaves the nozzle. By placing the horizontally blowing nozzles in succession at suitable distances below the roof, even a large supply air flow can be transported with a relatively small air flow to tens, even hundreds of meters, and distributed to the living area with vertically blown air jets. The ratio of the main supply air flow to the air flow of the jets can be, for example, 5: 1. The cost of the air transport system will be reduced accordingly.

In addition, air-jet systems are the only way to provide satisfactory ventilation in rooms where large ducts cannot be located, for example due to crane tracks, or in individual workstations where ducts cannot be brought close due to the work process or other reasons.

5 A special advantage / application is the equalization of temperature differences in tall buildings. The warm air rises upwards, creating a so-called the temperature deposition, which can easily be 5-7 ° C, even higher depending on the heat sources, i.e. the air temperature in the upper 10 parts of the room is 5-7 ° C higher than at the floor level where people still live. Downward-facing showers placed on the ceiling edge draw warm air with them down to the living area and thus even out temperature differences. Since a reduction in temperature to 1 ° C generally corresponds to a reduction in heating energy consumption of about 5%, it is easy to see that large energy savings can be achieved by compensating for temperature differences.

However, current nozzle systems have serious weaknesses. In order for the air to be induced, i.e. drawn in, a large number of nozzles with a high air velocity have to be installed. This results, firstly, in high ducting and installation costs, in particular because each nozzle usually has to be oriented afterwards, once the location of the people in the air-conditioned area 25 has been determined, so that the air jet does not create a harmful draft for the living area. Second, high jet speed inevitably results in high pressure drop in the nozzle and further high power consumption in the nozzle system in the air supply fan, expensive fan and electric motor, wiring, connection charge, etc. High nozzle speed also inevitably leads to high noise levels , i.e. non-industrial premises.

A further serious weakness is that much of the power consumed is used instead of compensating for temperature differences 101826 3 for inadvertent air recirculation in a ventilated space. This is because when air is blown at a high speed from a relatively large nozzle (e.g. 50-150 mm in diameter), the speed in the jet is still high at a distance of 5 to many meters from the starting point. In this case, in addition to the roof boundary, the shower also induces air from the middle and lower parts of the room, where the air is cooler, and only a part of the total air flow participates in compensating for temperature differences.

The simplest way to reduce the disadvantages of a high jet output speed is to reduce the jet speed. In this case, however, the air flow must be increased in order to achieve the same induction effect, i.e. the mixing of the ambient air with the shower and the same length of the shower. In this case, the channelization costs increase and the placement of the channels 15 becomes more difficult, the number of nozzles increases and / or they increase, etc., i.e. a substantial part of the advantages of the system is lost.

FI patent application 962774 discloses a method by which most of the induction air is obtained in the vicinity of the hall roof 20 and on the other hand the air speed in the shower can be reduced and thus the power consumption and the sound level can be reduced. The method is based on combining several jets so that the central carrying jet is surrounded by several smaller, substantially free-forming jets.

25 The above-mentioned nozzle systems are useful when the height of the building is relatively high, usually more than 6 meters. If the height is lower than this, the diameter of the nozzle and / or the outlet speed of the shower must be reduced in order to avoid too much disturbing draft in the living area. 30 due to high air speed. Both measures lead to an increase in the number of nozzles. In addition, both degrade the induction, so the airflow must be increased, which further increases the number of nozzles. The result is such a sharp increase in duct and installation costs that nozzle systems 35 are generally not competitive in buildings less than 6 meters high, despite many good features.

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However, the most serious weakness is that nozzle systems perform poorly when the building needs cooling. In summer, it would be advantageous to allow the heat to rise and form a deposit from which air could be removed at 5 superheat. The nozzle system blows the superheated air down and thus increases the heat load at the residence level. Even a temperature layer of up to 4 ° C would reduce the cooling capacity required by the building, usually by 20-40%, depending on the internal loads.

10 For premises requiring cooling, a so-called active exclusion. The air distribution is spread over a large surface. Air flows into the room from small nozzles at high speed and mobilizes a large mass of air. When the air jet from the small nozzle is small, no sound-15 disadvantages occur despite the high speed. The speed of the air in a small shower decreases quickly, so traction does not occur easily. When a large air mass is in motion, the disturbances affect the flow only locally, so the ventilation throughout the room is even. Thanks to the large 20 mixing ratio of the supply and room air, the temperature differences are evened out, so that even cold supply air can be brought into the living area without the flow "falling". There is no floor tension with a temperature difference of 15 degrees yet.

The airflow can be adjusted over a wide range. Active-25 displacement is therefore very well suited for cooling. This method of air distribution is described in FI patent publications 79608, 73513, 72800 and 71417.

However, if the supply air is considerably warmer than the room air, even a small temperature difference after strong mixing will cause the air to rise out of the living area. Active displacement is thus ill-suited to heating. There have been many attempts to eliminate this disadvantage. For example, FI patent publication 90466 discloses an apparatus in which supply air is led in heating and cooling situations through different flow paths to nozzles, from which it is blown in different directions so that a different flow field is formed in summer than in winter. In this way, good properties are maintained in a cooling situation, such as high cooling capacity, draft-free air distribution, formation of a temperature layer, etc. The device also operates in a heating situation with reasonably superheated air.

However, the hardware has some weaknesses. First, the temperature deposition is not eliminated in winter, leading to a significant increase in energy consumption compared to the nozzle-10 blowing system. The cost of the hardware is also high, due to the fact that the replacement damper and its actuator as well as the partition are relatively expensive. In addition, the winter and summer flow paths both have to be dimensioned for full airflow, which increases the diameter of the inlet pipes. Of course, the costs increase and, in addition, placing a large-diameter inlet pipe in a room is often difficult.

The object of the invention is to provide an apparatus by means of which the disadvantages of the prior art can be eliminated. This is achieved by means of the apparatus according to the invention, which is characterized in that the apparatus alternately comprises a nozzle blowing device or devices and a displaceable air distributor or displacement air distribution devices.

The basic idea of the invention is to combine nozzle blowing and active displacement as equipment 25 while maintaining the advantages of both. The apparatus consists of a plurality of elongate substantially parallel, substantially horizontally mounted air distribution devices. The equipment alternates between nozzle blowing devices and displacing air distribution devices-30 as noted above. Both the displacement air diffusers and the nozzle blowers have their own separate distribution duct system, which can be completely or partially closed and through which the air flow can be adjusted if necessary. Air treated in different ways can flow in the distribution ducts.

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With the apparatus according to the invention, it is possible to bring 15 ° C under-temperature and 15 ° C over-temperature air into the room. It is therefore even suitable for air heating systems. Temperature deposition can be maintained in summer and removed for winter, resulting in lower thermal energy consumption than in any known equipment. Thermal energy here means heating and cooling. The airflows are adjustable over a wide range, which reduces the consumption of both thermal energy and electrical-10 energy. The air distribution is draft-free and its noise level is very low, considerably lower than, for example, in the nozzle blowing system described above. The pressure drop of the equipment is low. The equipment is suitable for even low spaces up to a room height of about 3 meters. Almost 15 complete units can be used both in summer and winter, which means that the investment costs are lower than, for example, in the publication of FI publication 90466. The cost is further reduced by the fact that the equipment does not have a replacement damper. Hardware fabrication can be automated and 20 installation as well as flow field adjustment is fast, further reducing costs. The pressure drop of the equipment and, as a result, the consumption of electrical power and the sound level are significantly lower than in known nozzle blowing devices.

In the apparatus according to the invention, the nozzle blowing 25 takes place from a large number of small nozzles arranged in a row, which effectively remove the temperature layer in winter and from which the outgoing jets converge at a short distance, generally less than one meter, from the nozzles. In this case, a strip-like, basically the entire width of the room is formed; 30 combined showers with a throwing length of up to 15 meters if required. The jets from the small nozzles very effectively induce the surrounding air right from the top of the hall, but when the jets combine into a strip-like main jet, the induction is substantially reduced and the jet extends far.

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Both displacing air distributors and nozzle control devices are known to operate over a very wide airflow range, so the total airflow of the equipment as well as the partial airflow-5 to both air distributor groups can be adjusted over a wide range and adapt the equipment to the optimum operating situation and save energy.

In both types of air distribution, air flows into the room from a large number of small openings where the power level of the generated sound is low. In addition, the sound from a small opening is effectively attenuated by the so-called thanks to end attenuation, so the equipment also effectively attenuates the sound of the air conditioning plant fan.

15 In winter, the system operates by supplying supply air to both air distributors with a temperature higher than room temperature. As is known, superheated air tends to rise from the displacing air distributor up to the ceiling boundary and form a strong thermal layer. However, the strip-like shower coming from the jet blower forces most of the upwardly flowing air into the living area and the part that enters the top of the space is induced to enter the shower at its initial end. In this way, the displacing air supply also works in the heating situation and the temperature layer is removed in winter. The apparatus also operates in very shallow spaces when it is realized that the air jet does not need to be directed straight down, but takes the upward air from the displacing supply air device more effectively down if the displacing air distributor and the jet blower; The 30 devices are horizontally at a suitable distance from each other and the jets are directed obliquely downwards, the more horizontally the lower the space and / or the stronger the jet needed to bring the upward warm air to the living level.

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In summer, the blasting system is completely or partially closed and the system operates only on the principle of displacement, in which case a temperature layer is formed in the room. The jet blowing equipment can be kept running in such parts of the room where, due to the lack of heat sources, disturbance flows, moving machines, etc., no temperature deposition is formed. As stated above, the airflow of the blasting equipment is small, generally less than 20% of the total airflow. As a result, a considerably smaller part of the overall equipment is out of use than, for example, in the solution of FI-90466.

Both air distribution devices are in principle able to automate the production of small nozzles in direct ducts, so that the manufacturing costs remain reasonable. Installation costs are also reasonable due to the large airflow / air distribution unit. Overall, the cost / m3 of supply air is fully competitive with the air distribution equipment on the market.

Instead, the performance is unique. According to the measurements, the apparatus is capable of introducing a cooling power of more than 150 W / m2 and a heating power of more than 100 W / m2 to the air-conditioned space without draft, maintaining or removing the temperature layer and independently controlling both the jet airflow and the displacement airflow. No known system can come close to this.

The invention will be explained in more detail by means of the exemplary solutions described in the accompanying drawing, in which Fig. 1 shows a schematic side view of an example of a known solution, Fig. 2 shows a schematic end view of the solution according to Fig. 1, Figs. 3A and 3B schematically show an example of a known solution Fig. 4 shows a schematic end view of a first embodiment of the apparatus according to the invention, Fig. 5 shows a schematic side view of a first embodiment of the apparatus according to the invention, Fig. 6 shows a schematic top view of a first embodiment of the apparatus according to the invention, Fig. 7 shows a schematic side view Fig. 8 schematically shows a third embodiment of the apparatus according to the invention, Fig. 9 shows schematically Fig. 10 is a schematic view of a fifth embodiment of an apparatus according to the invention, and Fig. 11 is a schematic view of a sixth embodiment of an apparatus according to the invention.

The prior art apparatus illustrated in Figures 1 to 3B shows a displaceable air distributor. In Fig. 20 1 the damper 7 is in a position corresponding to summer use, whereby the supply air flows through the duct 4 to small (3-8 mm) nozzles 8, from which it discharges into the air-conditioned space as small jets with a relatively high flow rate, thus inducing a large amount of ambient air. whereby the flow velocity slows down in a very short distance below the tensile limit of 0.2 m / s (300 - 600 mm). Since the supply air temperature is lower than the room air temperature, the flow turns downwards and a flow field according to Fig. 3A is formed, which is very stable and draft-free.

In winter, the damper 7 is in the position indicated by broken lines in Fig. 1, and the supply air flows through the duct 5 and the nozzles 9, whereby a flow field according to Fig. 3B is formed in the space to be ventilated. However, the air cannot be very superheated, up to 4 - 5 ° C, otherwise it will rise 35 up from the living zone. In the cooling situation, a very useful 101026 10 excellent induction slows down the supply air flow rate also in the heating situation, whereby the supply air, which is warmer than the room air, rises upwards away from the living zone. Em. The temperature difference of 4-5 ° C compared to room air-5 na covers the control range required for very demanding ventilation, but is completely insufficient for air heating. Nor does it remove the temperature layer, and it has the other disadvantages outlined above.

Figures 4 to 6 show a first embodiment of the apparatus according to the invention, in which air flows through the damper 8, the filter 9, the heat recovery device 10 and the heating coil 11 in a conventional manner to a fan 12 which blows it through the damper 13 to the air duct 14 and in winter via 15 jet blowers to 2 distribution ducts 6.

Supply air warmer than room air flows from the displacing supply air device 1 as shown by the arrows in Fig. 4 and starts to flow upwards. The part rises below the roof 4. The air jets leaving the nozzles 20 of the nozzle or jet blowing devices 2 at high speed draw the warm air accumulated at the roof boundary by induction to the living zone. The showers also turn most of the supply air leaving the distributor 1 downwards, so that all the supply air can be brought to the residence area and the temperature deposition can be removed.

The nozzles 3 are small in size, for example 8-25 mm in diameter and are mounted in a row in an elongate distributor 2 as shown in Fig. 5. As is known, the induction of a small jet takes place in a very short distance, i.e. the jets take the warmest air from the ceiling very efficiently, much more efficiently with a nozzle diameter of generally 35 to 150 mm.

The speed of the small shower decreases with a short distance-35 Sat. However, the air jets are known to expand as the distance 101826 11 from the nozzle increases, with the jets close to each other merging at a certain distance from the nozzles. If the diameters and the mutual distance of the nozzles 3 are chosen appropriately, the jets are made to coalesce before the speed in them 5 has decreased too much. In this case, a strip-shaped combined jet of the entire width of the nozzle-blowing device is formed, the induction of which is substantially smaller than the induction of a single circular jet, and in this case the jet extends far. The combined jet behaves in principle like a jet leaving a slot nozzle, which is known to achieve the maximum possible throw length.

The induction of the apparatus according to the invention is substantially more efficient in the vicinity of the roof and the throw length is longer than with known nozzle blowing devices. Both mats are known to be directly proportional to air velocity. Conversely, a certain induction and throw length can be achieved with the apparatus according to the invention at a lower nozzle speed than with previously known devices. In this case, the pressure drop and the power consumption directly proportional to it are smaller and the sound level is lower than in previously known devices. For example, the above-mentioned fact allows the use of a nozzle-blowing system in rooms with a relatively strict sound level requirement, for example in meeting rooms, offices, etc., which has not been possible with the prior art.

As can be seen from Figure 4, the air does not flow straight down from the nozzles 3, but diagonally downwards. This makes it possible to apply the equipment to rooms of different heights. By changing the blowing angles of the nozzles, the air speed 30 in the nozzles and the mutual distance of the air distribution devices 1, 2 horizontally and especially vertically, the equipment consisting of the same components can be easily converted to very different heights and / or different airflows / floor-m2.

35 The equipment is suitable for rooms up to 3 m high, although 12 ΊΠΊΠΟ / Τ iU ίΟΖϋ, although its benefits are limited. The nozzles 3 then blow almost horizontally and the height difference of the distribution devices 1, 2 is small. At the other extreme, in buildings over 20 m high, the height difference is large and the nozzles 3 5 blow almost or completely vertically down.

The body of the air distribution devices 1, 2 can be a conventional threaded air conditioning duct, which according to the prior art can be manufactured at a very low cost in a conventional threaded sealing machine. The small-sized nozzles 10 in the dispensers 1, 2 can be drawn with a press tool either into a finished pipe or preferably into a raw material used sheet strip by connecting the nozzles pulling the press tool to a thread strip machine pre-treatment step, whereby the nozzles are provided

It is, of course, possible to make loose nozzles or groups of nozzles in series, which, for example, are fastened with a forcing tool to a duct made from a perforated plate strip or to a pre-perforated duct. It is possible to automate work steps.

The above descriptions of manufacturing methods are only examples intended to demonstrate low manufacturing costs. All methods of preparation known per se are, of course, within the scope of the invention.

The low installation cost is mainly due to the large number of nozzles included in the units to be installed. For example, a conventional unit length of 6 meters has an air flow of 30 m3 / s per supply air unit of the displacing air distribution. One alignment operation can also be used to orient several nozzles as described later.

It has been found that the orientation of the nozzles in this apparatus is not as important as in a conventional nozzle management system. Moreover, in this system it can be replaced by air flow control or by changing the height difference of the air devices, which requires easily adjustable suspension devices, which are known per se, mainly for the nozzle blowing devices 2.

Instead, the regulation of the air flows independently to each of the 5 distribution ducts 1, 2 is very important, especially in air heating. Compared to the prior art, the consumption of both electrical and thermal energy can be substantially reduced if the supply air temperature is kept constant as the heat demand decreases and 10 supply air flows are adjusted instead of the temperature. Thermal energy consumption decreases mainly * due to an increase in the efficiency of the heat recovery device 11, but the electricity consumption of the fan decreases considerably more.

The adjustment can take place according to Fig. 6 on the control dampers 13, 14. However, this adjustment has the weakness that the electricity consumption decreases only approximately directly in proportion to the air flow. As the air flow decreases, the pressure drop of the displacement air devices 1 would also decrease in proportion to the second power of the air flow, so from this, i.e. more than 80%, the power consumption could be reduced in proportion to the third power of the air flow, i.e. heat consumption. When the peak heat consumption occurs in less than 20 hours, the heating period is 5000 to 6000 hours, and the average consumption is less than 50% of the peak, the power consumption of the fan 25 could be reduced to less than 30% by providing fan 12 with speed control and dampers 13, 14 only. , 2 to keep the pressure levels correct.

However, this is not the case, since the air flow of the nozzle blower devices 30 cannot be said to be reduced, since the jet must extend into the living area. A slightly weaker shower is sufficient to reverse the reduced airflow of the manifolds 1, but the change is quite small. The fan must thus maintain an almost constant pressure level, from which the excess 35 is "killed" by the damper 14.

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However, if a small auxiliary fan 17 is placed in the distribution duct 7 according to Fig. 7, the pressure of the fan 12 can be reduced to the level required by the displacement devices 1 and the additional pressure required by the nozzle blowing devices 2 can be developed by the fan 17. The annual power consumption of the equipment decreases to less than one third.

Even lower power consumption and lower costs are achieved in that the nozzle blower parts 2, 6, 17 of the apparatus are not connected to the air handling unit 8-12, but function as an independent subassembly which can take the air it needs from the air-conditioned space. The air treatment apparatus 8-12 decreases correspondingly to the air flow of the nozzle blowing apparatus 1, 6, 17, and the pressure loss caused by the apparatus 8-11 is eliminated from this air-15 flow section.

The figures show that the entire air flow is taken through the heat recovery device 10, i.e. from the outside. It is of course clear that a solution known per se, in which only the air flow required to maintain air quality is taken through the heat recovery device 20 and the additional air flow required for heating is taken as circulating air flow from the air-conditioned space, for example between the heat recovery 10 and the heating coil 11, is within the scope of the invention. and system solutions.

As the outside air temperature rises and the heating demand changes to the cooling demand, the nozzle blowers 2 are switched off by closing the damper 14 in Fig. 6 or 30 by stopping the fan 17 in Fig. 7. In rooms with strong temperature deposition, the living area temperature can drop adversely, but is usually re-established. It must be remembered that in a properly designed plant, the exhaust air temperature also rises due to temperature deposition.

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In rooms where no temperature build-up occurs in summer or only part of the air-conditioned room is formed, the nozzle blowing equipment can be left running. Such an embodiment is shown in Fig. 8, in which the nozzle blowing devices 5 are excluded by means of the damper 15 from the area B delimited only by dashed lines. A typical example of a state in which the temperature deposit is formed only in winter is a radiator-heated state without other heat sources.

If the nozzle blowing devices 2 are not in use during the cooling period, it is advantageous to place the cooling coil 16 in the displacement air distribution duct 7 according to Fig. 9. Accordingly, part of the heating power can be supplied according to Fig. 9 only by the nozzle blowing device distribution duct 15 but 6 when this is necessary. the distribution duct 6 is not connected to the air conditioning equipment 8 to 12, but is separate and equipped with its own fan. The radiator 16 can, of course, be placed in the usual way between the heating radiator 11 and the fan 12 20.

It has been stated above that the orientation of the air jets of the nozzles 3 is generally not necessary. It can be replaced by height adjustment or, for example, by equipping the nozzle blowing devices 2 with single-adjustment dampers. It is also possible to use directional nozzles known per se, or to use one or, according to Fig. 10, two nozzle blowing devices 2 with only one row of nozzles. The orientation takes place simply by turning the distributor 2.

The invention has been described above in its most preferred form of Tote-30, in which the air distribution devices 1, 2 at the same time form ** an air transport channel. Of course, the basic idea can also be realized according to Fig. 11 by connecting separate displacement supply air devices 20 arranged in a row in separate air supply ducts 7. Correspondingly, the nozzle-35 blower can be replaced by a separate air duct and 101826 16

The application examples presented above are in no way intended to limit the invention, but the invention 5 can be modified completely freely within the scope of the claims. Thus, it is clear that the apparatus according to the invention or its details necessarily have to be exactly as shown in the figures, but other solutions are also possible. The invention is described in 10 examples, for example only connected to a certain type of air conditioning equipment 8-12. However, it is clear that the invention can be applied in connection with all device and system solutions known per se, for example in connection with an integrated system according to FI publication 92867.

Claims (13)

101826 π Apparatus for distributing supply air, in particular to large and / or medium-height air-conditioned rooms, comprising a plurality of elongate air distribution devices mounted in a substantially parallel and substantially horizontal position, characterized in that the device comprises an alternating nozzle blowing device or devices (2) air distributor or 10 displacement air distributors (1). Apparatus according to Claim 1, characterized in that the nozzle blowing devices (2) are arranged above the height-displacing air distribution devices (1). Apparatus according to Claim 1 or 2, characterized in that the air is arranged to be supplied to the displacement air distribution devices (1) via one distribution duct (7) or distribution duct group and to the nozzle blowing devices (2) via another distribution duct (6) or distribution duct group. Apparatus according to one of the preceding claims 1 to 3, characterized in that the outflow openings (3) of the nozzle blowing device (2) are arranged to form one or more longitudinal rows. Apparatus according to one of the preceding claims 1 to 4, characterized in that the outflow openings (3) of the nozzle blowing device (2) are small-sized nozzles or groups of nozzles. Apparatus according to one of the preceding claims 1 to 5, characterized in that the outflow openings (3) of the nozzle blowing device (2) are directed so that the flow leaving them is directed in the vicinity of the displacing air distributor (1). Apparatus according to one of the preceding claims 1 to 6, characterized in that the distribution channel (6) of the nozzle blowing devices (2) has a closing device or closing devices (14, 15) adapted to partially close the nozzle blowing devices (2). or completely disabled. Apparatus according to one of the preceding claims 1 to 7, characterized in that a booster fan (17) is arranged at the beginning of the distribution channel (6) of the nozzle blowing devices (2). Apparatus according to Claim 8, characterized in that the distribution ducts (6, 7) or duct groups of the nozzle blowing device (2) and the displacing air distribution (1) are separate parts of one another. Apparatus according to one of the preceding claims 1 to 9, characterized in that a heating coil (18) is arranged at the beginning of the distribution duct (6) of the nozzle blowing device (2). Apparatus according to one of the preceding claims 1 to 10, characterized in that a cooling coil (16) is arranged at the beginning of the distribution duct (7) of the displacing air distribution (1). Apparatus according to one of the preceding claims 1 to 11, characterized in that the displacing air distribution device (1) is formed by an air transport duct (7) to which a plurality of separate air distribution devices (20) mounted in a row are connected. Apparatus according to one of the preceding claims 1 to 12, characterized in that the nozzle blowing device (2) is formed by an air transport duct (6) to which a plurality of separate air distribution devices mounted in a row are connected. 101826