EP0667946B1

EP0667946B1 - An arrangement in connection with an air conditioning unit for large spaces

Info

Publication number: EP0667946B1
Application number: EP93924635A
Authority: EP
Inventors: Heikki Peltola
Original assignee: FLAEKT Oy; ABB Flaekt Oy
Current assignee: Flaekt Woods Oy
Priority date: 1992-11-10
Filing date: 1993-11-10
Publication date: 2000-04-26
Anticipated expiration: 2013-11-10
Also published as: FI925105A; PT667946E; EP0667946A1; FI925105A0; FI97166B; DE69328491D1; ATE192227T1; DE69328491T2; FI97166C; WO1994011678A1; AU5422894A

Abstract

The invention relates to an arrangement in connection with an air conditioning unit, comprising at least one fan (4) fitted within a casing structure, means for conveying untreated outdoor and indoor air into the casing structure, and distributor means (9) for distributing air into the interior space of the building to be air conditioned. To improve the overall economy of the air conditioning unit, the arrangement is constructed as a wall-mounted unit and the distributor means (9, 19) for distributing air into the interior space are integrated in the same unit with the other components of the arrangement.

Description

The present invention relates to an arrangement in connection with an air conditioning unit for large spaces, comprising at least one fan fitted within a casing structure, means for conveying untreated outdoor and indoor air into the casing structure, and distributor means for distributing air into the interior space of the building to be air conditioned.
Arrangements of this kind are well known in connection with heavy industry, for example, the wood processing industry. Nowadays ventilation of industrial premises is most often implemented by means of what are called roof-top units. Roof-top units are installations in which fans are fitted in a unit placed on the roof of a building, wherefrom air is conveyed through ducts into the building. Several units of this kind may be provided on the roof of the building.
The drawback of the above previously known solutions is their weight, i.e. the fact that heavy units installed on rooftop require a very robust method of construction. In the Nordic countries, a heavy method of construction has been traditionally used, which has enabled installation of roof-top units. In Central Europe, however, a lighter method of construction based e.g. on steel structures is used, and thus roof-top installations are not possible without considerable reinforcement of the structures. The above lighter method of construction has gradually become more common also in the Nordic countries. Further drawbacks of the prior art include maintenance and control, which must be performed out of doors. In addition, accessibility problems presented for instance by snow must be taken into account in the structures. The cost for the ductwork can be high, its placing in the building difficult and, in consequence, air distribution impractical.
On the other hand, air conditioning of small spaces, such as clean rooms, ADP rooms, hospital and office rooms etc. is typically realized by means of small-sized room air-conditioning machines and jet and fan convectors which are usually designed to stand freely in the space to be air conditioned and to recycle the air within the room. At the same time, the air is treated in some manner, for instance cooled and/or filtered. Also outdoor air may be taken in, but since the air intake is usually low on account of the small size and structural reasons, outdoor air must be taken in through ducts, in order that no dust, gases or other impurities from the earth level may enter into the inlet which is located too low. Such machines are known for example from Finnish Patent 30 076 and Finnish application 860635, Figure 3 in the latter publication showing also conventional arrangements for outdoor ducting.
These units are normally small in size, wherefore several of such may be required for the air conditioning of even a small space, as is seen from Figures 2, 3 and 4 in Finnish application 860635. A normal-size unit fits under a window, for example, as is seen from Figure 1 in Finnish Patent 30 076. The ventilation of large industrial halls would require as many as hundreds of such units, and for this reason alone they are not used in industry.
Another, possibly more serious reason is that typically with such machines air is blown into the room space from the upper part of the machine upwardly, as in Figure 1 in Finnish Patent 30 076, or at least from the upper part of the machine, which produces an inclined upward free flow. If the machine is small and located in a relatively low space, either the flow is self-directed or at least the ceiling deflects it to the breathing zone, which will provide satisfactory ventilation performance. On the other hand, high industrial halls need large air flows. Blowing upward would entrain the flow to the ceiling to a height of several metres, i.e. away from the breathing zone, as a result of the mass effect. Since for several reasons exhaust air devices are usually installed high, the air would arrive directly at the exhaust and a short-circuit flow would be produced. Further, blowing from above requires mixing air distribution, which owing to the large air flows required would render a large area in the vicinity of the machine useless.
A further prior art that is of interest is DE-A-1 753 831 that is concerned with an air treatment unit constructed so as to act as a substitute for a part of an outside wall of a building. Its main purpose is to extract moisture from air extracted from a room and then to return dried air back to the room preferably at a temperature slightly higher than the room air temperature. This prior art teaches that the unit shall have outdoor air plates that may be opened whereby a small amount of outdoor air can be mixed with some of the air that has been dried.
The unit comprises an upper horizontally extending cylindrical type fan that draws air from the room into the unit through a vertically extending mesh screen. The unit also comprises a lower horizontally extending cylindrical type fan there being an upwardly and rearwardly extending plate in the unit curling at its upper end around the rear of the upper cylindrical type fan, and extending at its lower end over the front of the lower cylindrical type fan.
The upper cylindrical type fan causes air from the room to pass through said mesh screen and to flow downwardly over said upwardly and rearwardly extending plate such that said air passes through an evaporator by means of which moisture is condensed from the air and falls into a gutter for removal. Some of the dried air is then guided back into the room in a horizontal direction via a vertically extending lower air distributor extending along the lower edge of said mesh screen. The remainder of the dried air is drawn by the lower cylindrical type fan under the lower edge of said upwardly and rearwardly extending plate and causes dried air to flow upwardly behind said upwardly and rearwardly extending plate past adjustable flaps permitting fresh air from the outside to enter via louvres mounted at the lower outer face of the unit. The resulting mixed air then flows back into the room in a horizontal direction via a flow channel positioned above said upper cylindrical type fan and via a vertically extending upper air distributor extending along the upper edge of said mesh screen.
A draw-back of this prior art is that since it is relatively small in height compared with the height of the room in which it is installed and since the dried air is directed in a horizontal direction into said room the whole of the air in said room cannot be effectively treated. The reason for this is that air passing horizontally into the room via said upper and lower air distributors does so in close proximity to the flow of air out of the room towards said mesh screen and thus the air returned into the room tends to mix immediately with the air being drawn towards said mesh screen. In this manner the bulk of the air in the room is not circulated through the unit. A further draw-back of this prior art unit is that it is not capable of producing large air flows as is necessary if large spaces, for instance industrial halls, are to be air treated.
It is an object of the present invention to avoid the draw-backs of the prior art.

The invention

The present invention is as defined in the accompanying claims.
In its widest aspect the present invention comprises an arrangement in connection with an air treatment unit for large spaces, for instance industrial halls, comprising more than one fan fitted within a casing structure, means for conveying untreated outdoor and indoor air into the casing structure, and distributor means for distributing air into the interior space of the building to be air treated;
said arrangement being constructed as a wall mounting unit by constructing the arrangement to act as a substitute for a part of a wall of the building to be air treated and/or by constructing the arrangement to fit in the unused space between two or more load bearing vertical columns of the building to be air conditioned in order to utilize said unused space;
said air distributor means being integrated into said unit and comprising an air distribution surface at its lower end that is disposed in an inclined position such that at its bottom end the horizontal internal cross-sectional area of the casing structure is less than the horizontal internal cross-sectional area of the casing structure at the upper end of said distribution surface.
Thus the present invention as described in Claim 1 differs firstly from the state of the art DE-A-1 753 831 in that it embraces air treatment units that are sufficiently great in size as to fit in unused space between two or more load bearing vertical columns of a building to be air treated. With this distinguishing feature a single air treatment unit can be created that is sufficiently great in its vertical cross-section in the plane of the wall in which it is mounted as to be capable of carrying out air treatment for large spaces such as industrial halls.
Further, the present invention differs from the state of the art DE-A-1 753 831 in that it has an air distribution surface at its lower end that is disposed in an inclined position such that at its bottom end the horizontal internal cross-sectional area of the casing structure is less than the horizontal internal cross-sectional area of casing structure at the upper end of the air distribution surface. Such an arrangement and location of the air distribution surface assists in ensuring an improved handling of the air volume in a room to be air treated.
The advantages of the invention also include the fact that all maintenance points are located indoors. It is a further advantage that one avoids using special elements in roof structures, and the piping, electrical, control and cabling works are moved from the roof to indoors, and the number of inlets through the roof is substantially diminished from that used in the prior art solutions. Still another advantage is the fact that stresses on the roof structures are diminished from those encountered with the prior art solutions. Owing to these facts, the total economy of the arrangement of the invention will be advantageous in view of the investment, running and maintenance costs. All maintenance points are located in the lower part of the machine, thus enabling maintenance to be carried out from the floor. Also, it is possible to arrange the maintenance to be carried out from the space that the unit or arrangement serves, as set out hereinabove, or through a wall from outside the building. Further advantages of the invention include the fact that the arrangement is well suitable for renovation, and the fact that problems presented by condensed water in the prior art solutions are eliminated. Air distribution can be advantageously arranged, also as a combination of various methods of air distribution, and it can utilize the other components of the unit, such as the fans and filters. A collecting or distributing throw pattern can be simply produced with fan impellers rotating in different directions. The combination of various methods of air distribution can be achieved for example in such a manner that carrier jets are induced by a slot or nozzle, and these jets shape the throw pattern. The inclined front wall of the air distributor means is advantageous when displacing air distribution is employed. The filter may advantageously be integrated with the air distributor means, in which its pressure losses are utilized to equalize the speed distribution of the air flow. When the air distributor means is used as a pressure chamber for the impellers, complete mixing of the air flow and a uniform temperature distribution is achieved also in cases where no heating is employed. A further advantage of the invention is that the air distributor means can also be equipped with a 'UNO' blowing surface. The arrangement enables the use of heat having a low temperature value, e.g. waste heat of various industrial processes, for heating or cooling. When direct blowers are used, the operating point of the impeller is optimized for instance by altering the blade angle or the diameter of the impeller. By this means, the power losses encountered in a belt drive are completely eliminated. By air flow measurement integrated in the fan, rapid and efficient control is achieved. The arrangement can be sewered in an advantageous manner so that condensed water does not present any problems, as has been stated in the above. For example, the support structures for the battery and the suction box for the fan can simultaneously serve as water-collecting drains. Thus it is possible to use the arrangement also for drying, whereby water is evacuated from the intake air. Given the absence of ducting, the constructions of the arrangement enable all parts of the system to be washed, since water does not present any problems. Furthermore, water condensed on the batteries or other parts of the arrangement can be used for cleaning the batteries. Also, the overall construction is advantageous, since the piping, control equipment, electrical equipment, ductwork, air distribution, air intake and air treatment are combined in the same construction.
In the following the invention will be set forth in greater detail by means of the preferred embodiments of the invention presented in the accompanying drawing, wherein
Figure 1 is a schematic perspective view of a first embodiment of the invention,
Figure 2 is a schematic front view of another embodiment of the invention, and
Figure 3 is a schematic sectional side view of the embodiment of Figure 2.
Figure 1 is a schematic representation of a preferred embodiment of the invention. Reference numeral 1 denotes a load bearing vertical column of the building, reference numeral 2 a wall of the building and reference 3 the floor. Reference numeral 4 in Figure 1 denotes fans, three of which are provided in this embodiment. Reference numerals 5 and 6 denote registers and reference numerals 7 and 8 heating or cooling batteries. Reference numeral 9 denotes generally the distributor means for distributing air into the interior space. In the embodiment of Figure 1, the distributor means comprise a slot nozzle 9a and an apertured plate 9b. The passage of air is shown by arrows in Figure 1.
In operation of the arrangement shown in Figure 1, air is drawn in by means of fans 4 either from outside or from inside or both into the casing structure in which said air flows are mixed. The mixed air is blown further by means of distributor means 9 into the interior space. The air quantities are controlled with registers 5, 6. The air temperature can be raised or lowered according to need with batteries 7, 8.
The units in accordance with the prior art solutions, such as those disclosed in Finnish Patent 30 076 and Finnish application 860635, are mainly intended to recycle air within the room they are installed in. It is generally not possible to take in untreated cold outdoor air; cf. page 1, paragraph 2 in Finnish Patent 30 076 and page 6, paragraph 3 in Finnish Patent Application 860635. The units disclosed in these publications are not suitable for intake of cold outdoor air, since upon the encounter of cold outdoor air and warm, humid indoor air, condensed water and ice are formed. Convectors are designed to operate dry or so that water is only found on the heat exchanger surfaces of the cooling battery. In the design/operating conditions of the invention, strong formation of condensed water and ice takes place in the mixing chamber upon the encounter of two air masses having a different state. Also, some of the surfaces within the apparatus are so cold that ice is formed on them. It has been a basis for the present design that water and snow formed within the apparatus do not hinder its operation. Mechanical operations are arranged in the less moist sections, and proper sewerage and sealing has been attended to.
In accordance with the essential idea of the invention, the arrangement is constructed as a wall-mounted unit and the distributor means 9 for distributing air into the interior space are integrated in the same unit with the other components of the system below them in the lower part of the unit. The term wall-mounted unit denotes an arrangement mounted to the wall of a building. The mounting site may be for instance the space between the load bearing columns 1 of the building, as shown in Figure 1. It is to be noted that Figure 1 shows only one column 1. Another column is in fact located on the left-hand side of Figure 1, but has not been illustrated. The arrangement may even be constructed to form part of the wall of the building to be air conditioned. In that case, the arrangement can also be advantageously formed such that it is installed in place from outside the building. However, the installation of the arrangement can naturally also be carried out from inside, even in a case where it forms part of the wall of the building. The distributor means 9 are arranged in the same unit, i.e. in the same aggregate with the other parts of the arrangement. The arrangement has, among other things, the advantage that lengthy and costly ducting, which was previously often required, is eliminated. The distribution of the air which is divided on a broad wall surface directly into the occupied zone is realized as displacing air distribution by means of a simple apertured plate, which can be made inclinable as shown in Figure 1. This feature is advantageous for the air distribution and, furthermore, leaves the floor free. The uniformity of the air distribution can be improved by arraying filters immediately in front of the air distribution surface, i.e. the apertured plate 9b. This arraying is also advantageous in view of space consumption. If the unit is located on the floor, air can be conveyed from its lower portion also into the floor beneath, as shown by an arrow in Figure 1. Furthermore, several methods of air distribution can be incorporated in the combined construction, such as the slot nozzle 9a shown in Figure 1 wherewith air is retained in the occupied zone also when heating is employed, in which event the air would otherwise rise towards the roof. The nozzle 9a can be provided with a shutting device, and thus the air distribution is as advantageous as possible also when cooling is employed.
Figures 2 and 3 show another advantageous embodiment of the invention. In the embodiment of Figures 2 and 3, fans are indicated at reference numeral 14. Registers are indicated at 15 and 16 and heating or cooling batteries at 17 and 18. Distributor means for distributing air into the interior space are denoted generally by reference numeral 19. In Figure 3, the passage of air is denoted by arrows.
The embodiment of Figures 2 and 3 corresponds in its operating principle and manner of installation to the embodiment of Figure 1, that is, the apparatus according to Figures 2 and 3 can be installed between the load bearing vertical columns of the building in the way shown in Figure 1, etc.
This embodiment is particularly preferred, because the air jet issuing from the unit can be expanded or reduced by making the fans 4 to rotate either in the same direction or in different directions. This can also be achieved, or the fan effect enhanced, with slot nozzles or rows of nozzles mounted on both sides or on one side of the plate 9b.
Maintenance operations for the embodiments set out above can be performed in the space that the arrangement primarily serves. The apparatus and components to be serviced are encased and can be serviced while standing on the floor. The batteries and possibly the electric motors can be serviced through separate service doors. The installation location of the arrangement can be the space between the load bearing columns of the building, which otherwise has no concrete use. The dimensions of the casing structure for the arrangement may be in the order of up to 5.4 m in breadth and 1.25 m in depth respectively, the distance between the columns being 6 m, and several metres in height. The arrangement can be installed in a steel-frame building or in a concrete-frame building. The arrangement can be supported to the wall, to the columns or to the root.
The above-presented exemplary embodiments are in no way intended to restrict the invention, which can be modified with complete freedom within the purview of the claims. It will be appreciated that the arrangement according to the invention or its details need not necessarily be precisely those shown in the figures, but other kinds of solutions, too, are possible. The number, effect and type of the fans have in no way been restricted, but these features can naturally be selected with complete freedom according to a given situation. This also applies to the air distributor means, which are constructed in accordance with the specific situation and the desired result. Furthermore, heating or cooling batteries are not indispensable in the arrangement, but the arrangement can also be realized without batteries. The arrangement can be constructed as a unitary component or formed as a modular construction which is transported in parts and assembled at site.

Claims

An arrangement in connection with an air treatment unit for large spaces, for instance industrial halls, comprising more than one fan (4, 14) fitted within a casing structure, means for conveying untreated outdoor and indoor air into the casing structure, and distributor means (9, 19) for distributing air into the interior space of the building to be air treated;

said arrangement being constructed as a wall mounting unit by constructing the arrangement to act as a substitute for a part of a wall (2) of the building to be air treated and/or by constructing the arrangement to fit in the unused space between two or more load bearing vertical columns (1) of the building to be air conditioned in order to utilize said unused space;

said air distributor means (9, 19) being integrated into said unit and comprising an air distribution surface at its lower end that is disposed in an inclined position such that at its bottom end the horizontal internal cross-sectional area of the casing structure is less than the horizontal internal cross-sectional area of the casing structure at the upper end of said distribution surface.
An arrangement as defined in Claim 1 and wherein its lower part is arranged to be in flow connection with the next floor thereunder of the building for conveying air also to said floor.
An arrangement as defined in Claim 1 or Claim 2 and wherein the air flow through said distributor means is arranged to be equalized by means of filters disposed in connection with said air distributor means (9, 19).
An arrangement as defined in any one of Claims 1 to 3 and wherein the air distribution surface is an apertured plate (9b).
An arrangement as defined in Claim 4 and wherein said air distribution surface also comprises a slot nozzle (9a).
An arrangement as defined in any one of Claims 1 to 5 and wherein the fans (4, 14) are adapted to serve as air flow directing means.