FI80517B - Method and arrangement for room air conditioning - Google Patents

Description

1 80517

METHOD AND APPARATUS FOR ROOM AIR CONDITIONING

The invention relates mainly to an air-conditioning method for office premises and light industrial premises and to an associated room-specific air handling unit.

Air conditioning in rooms requires that the necessary amount of ventilation air is supplied to and removed from them and that they are either cooled or heated as necessary. It is desirable that both ventilation and indoor temperature can be adjusted for each room or workplace.

Air conditioning methods are described, for example, in the Technology Manual, 8th edition, part 5, HVAC technology. Cooling power is usually brought into the rooms using either air or water. When using air, an amount of cool low-temperature air corresponding to the power demand is introduced into the room. The control is usually based on a variable amount of air and the method is called an air volume controlled method.

The maximum airflow to a room is determined by the power demand and undertemperature and is often greater than the need for room ventilation.

In this case, for energy economic reasons, the aim is usually to return part of the air back to the so-called as return. This can cause hygienic disadvantages and reduce indoor air quality, especially when exhaust air is used for all or a significant part of the building.

Room heating is usually carried out in an air-controlled method with separate heaters, either hot water or electric. Heating can also be treated with air with the help of cooling. but in that case there must be only a need for heating or cooling in the rooms covered by the method at the same time, and such a situation is rare.

The problem can be solved, for example, by drawing both cool and warm air ducts in each room and mixing cool and 2,80517 warm air in room-specific devices in the proportion required by the power demand. Such two-channel methods are often expensive and space consuming due to the high need for channels. They also easily waste energy when mixing different temperatures.

Another way to handle simultaneous cooling and heating is to post-heat the air going to the rooms where there is a heating need. Also in this case, energy is wasted when the air is first cooled and then heated.

Air conduction into the room can be implemented either in the so-called. mixing or displacing air distribution principle. In the mixing mode, the air is usually led from the wall or ceiling surface at a relatively high speed, aiming to mix as much room air as possible with the air to be blown in.

The air can then be introduced inside at very low temperatures without the risk of draft, whereby the air flow is correspondingly reduced in air-controlled methods. On the other hand, the efficiency of ventilation tends to be lower than in a displacing air distribution mode that seeks a piston effect.

In it, the air is led into the room usually from below at a low speed with only a little undertemperature. It spreads to the bottom of the room and rises as it heats up, pushing the polluted air to the top of the room from where it is removed. A prerequisite for displacing air distribution is low-temperature supply air. If the air is warm, it immediately rises upwards without being distributed throughout the room.

Because the undertemperature must be kept low due to the risk of traction, higher airflows are generally required for the same cooling capacity than in mixed air distribution. However, this is compensated by the stratification of the temperature in the room. Flow stability also requires relatively large airflows.

The characteristic features of the invention appear from the claims. Figure 1 shows an overview of the air conditioner.

Figure 2 shows the air conditioner in detail.

3 80517

The aim of the air-conditioning method according to the invention has been to eliminate the disadvantages of the air volume-controlled method described above and to utilize efficient displacement ventilation as well as to provide an easily modifiable solution that allows individual control. The method will be described below with reference to the accompanying figure, FIG.

Cooled air conditioning air (3) filtered and cooled in a local air conditioning unit (2) serving a limited area is led to an intermediate space or duct system (1) under a raised floor or formed in structures. It consists of a mixture of ventilation air (4) and local return air (5) supplied to the instrument in a ducted manner. The return air can also be ducted if desired.

The pressure in the intermediate space (1) is kept approximately constant and only slightly overpressured in relation to the room space, e.g. by adjusting the speed of the fans of the air conditioner. This does not place great demands on the tightness of the raised floor.

The temperature of the air conditioning air supplied to the intermediate space is always kept below the room temperature and at a temperature at which the cooling demand of the most heavily loaded room can be met. However, due to the relatively high airflows, the temperature is so high that the intermediate space usually does not need to be insulated.

The amount of ventilation air (4) introduced into the appliance through the duct is controlled by the according to the ventilation needs of the area. This can be done either manually or automatically, e.g. depending on the carbon dioxide content of the exhaust air. A corresponding amount of exhaust air (6) is discharged.

The room-specific air handling units (7) with fans in the rooms take in the amount of cool air conditioning air required for cooling from the intermediate space. The operation and structure of the devices are described in more detail below. The numbers refer to Fig.2.

In addition to the cool air conditioning air (3), the room-specific air handling units take the recirculated air (9) of the same 4 80517 room air through the filters (8) of the unit without mixing them, whereby the supply air (11) to the room room through the flow equalizer (10) (12) and the warmer upper zone (13).

This separation is effected by dividing the device into separate parts (14) and (15) by a partition (20). Mixing between the zones is low due to the low blowing speed and the lower zone always remains above room temperature. This has created the conditions for the implementation of displacing air distribution.

The device has the possibility to control the flow of cool air conditioning air taken from the intermediate space with a control device (16) and thus to control the cooling capacity and ventilation. In addition, the supply air flow can be adjusted by means of a fan (17), e.g. by controlling the speed of the motor (18).

As the need for cooling decreases, room-specific air handling units take less and less cool air conditioning air from the intermediate space until a space corresponding to the minimum ventilation requirement set for each room or workplace is reached.

If the cooling demand decreases even after this, the electric heater (19), for example, is switched on. It only heats the recirculated air (9) and thus it is possible to heat the room at the same time as cool supply air is introduced into the sub-zone, thus maintaining the operating conditions of the displacement ventilation even in the heating situation.

During the standstill, the air conditioning unit (2, Fig. 1) is not in operation and the connection of the room-specific air handling units to the intermediate space is closed by the control device (16). The air handling units now operate solely on recirculated air, heating the room as needed.

If there is no need for heating, the fans of the appliances will stop and the heaters will switch off.

The method of the invention and the associated room-specific air handling unit achieve significant advantages over current methods. They are described below.

Il 5 80517

Even today, office and other buildings often need cooling even in winter. The method then operates with air volume control, utilizing the principle of efficient displacement ventilation. It is essential that the air distribution in accordance with the displacement principle can be maintained even in the event of a heating demand.

The use of return air is limited to the area of the local air conditioner, which avoids the hygienic disadvantages of large-scale use of return air, eg for the entire building.

Workplace or room-specific recirculated air is cleaned in a filter, which can be very effective. When recirculated air is used in addition to ventilation and not on the farm, the cleanliness of the indoor air is improved.

The duct systems do not grow but decrease, because the supply air duct of the air volume-controlled part is the intermediate space of the raised floor or the cavities integrated in the intermediate floor, which are usually large enough for other reasons.

The need for ducts is further reduced if the narrow area exhaust air can be led to the air conditioner without ducting as shown in Fig. 1. Efficient displacement ventilation reduces the amount of air exchange air and thus also the air supply and exhaust ductwork.

Room-specific Air handling units can be freely placed where they are needed and controlled for each workplace or room. In addition to the temperature, the amount of ventilation can be controlled individually. Individual placement, orientation and adjustment options also reduce the risk of traction. The indoor climate is therefore perfectly controlled.

The entire method can be equipped with "intelligent" automation, which takes care of both ventilation and heating and cooling, ie the entire air conditioning according to individual wishes.

Changes to space arrangements are easy to implement. With regard to air conditioning, they are usually resolved by changing the location and quantity of the 6 80517 room appliances as required. When the loads change substantially, the change is coped with by replacing the air conditioner to correspond to the new situation. Ventilation can be handled centrally or decentrally, e.g. per floor.

Energy consumption is low e.g. because the ventilation volumes are small when using displacement ventilation, the ventilation can be controlled as needed and the free heat can be utilized efficiently. In rooms and workplaces where there is no supply, ventilation can be switched off completely while the heating is still operating. Air conditioners can operate either with centralized water circulation cooling or with their own compressors. Various heat pump applications are also possible.

To make the room unit work silently, select the fan correctly and, if necessary, silence the unit internally. The damping can advantageously be combined with a supply air flow equalizer. Noise transmitted through the recirculation opening is attenuated by the filter. Pu control also does not need to be used at full power other than during peak loads, where noise is better accepted.

The air conditioning method has been described above, which is based on the intake of cool air from an intermediate space or ductwork under a raised floor or formed in structures, and on the room-specific treatment of air in floor air handling units.

However, the method can be turned upside down and the air can be taken from the space or ductwork above the lowered roof, for example. The room devices are then located on the ceiling and the cool air, supported by a zone of warm air, spreads to the top of the room and then descends, causing a displacing air distribution similar to the piston effect.

; The air conditioner can be located either on the ceiling or further on the floor, in which case the intermediate space in the ceiling as well as the ventilation and exhaust ductwork is connected to it via connecting ducts.

This method also achieves piston-like displacement ventilation and achieves the same advantages as described above. Method 7 80517 and the room device are not separately described because, except for the operation of the zones and the upside-down location, the method and the room device are the same as above.

Claims (6)

1. A method for air conditioning of room spaces, in which a space such as 1 floor installer is located under an elevated floor and in the ceiling installation above a lowered ceiling or tiles or channels (1) formed in structures are supplied in a local unit assembly (2 ) treated, cool conditioning air (3) at a temperature lower than the room temperature, characterized in that separate air-conditioning appliances (7) provided with fans (17) provided for each room take in addition to the cool air (3) needed for ventilation and cooling of the room space in the filter (8) of the apparatus purified and, when required in the heater (19), heated circulating air (9) from the room in question without however mixing them, the conditioning air (3) forming a cool zone ( 12) and circulating air (9) a hot zone (13) in the supply air (11) which is supplied to the room at a constant speed, so that in the floor installation room the cool air in the lower part of the room spreads. and then rises upwards as it is heated and in the ceiling installation the cool air carried by the zone of warm air spreads in the upper part of the room and then sinks downwards and causes in the installations both a piston action similar to a pressing air distribution. Apparatus (7) for air conditioning of room spaces which serves as a separate air conditioning apparatus for each room in the method according to claim 1 and which, when arranged in the floor plan, takes cool conditioning air (3) at a temperature lower than the room temperature by a a motor (18) driven fan (17) from a space below the floor and, when arranged in the ceiling, from a space above the lowered ceiling, or from hollows or ducts (1) formed in structures and circulating air (9) which is purified in the filter (8) and, if necessary, heated in the heater (19), characterized in that the preferably cylindrical apparatus has a separate contouring chamber (14) separated by a partition wall (20) and a separate circulation air chamber (15). through which air flows are conducted by one and the same, the chambers by means of an intermediate disc (21) in two parts dividing into fan (17) without, however, mixing air flows through a flow low-speed air conditioner (10) Into the room space, the conditioning air (3) fr The unit arranged on the 1 floor plane forms a cool lower zone (12) 1 to the air (11) and the circulation air (9) to a warm upper zone ( 13) ensuring that the cool air of the lower zone blows into the lower part of the room and then heats up and produces, through the upper zone's involvement, a piston action similar to the expected narrowing air distribution and whereby the conditioning air (3) from the air supply to the ceiling air 11) a cooler upper zone (12) and circulation air (9) a warm lower zone (13) so that the lower zone's cool air spreads in the lower part of the room and then rises heated up and Astadkonuner through the upper zone's involvement a piston action similar upwardly directed narrowing air distribution and wherein the conditioning air (3) from the apparatus arranged in the ceiling plane forms in the supply air (11) a cool upper zone (12) and the circulation air (9) a warm lower zone (13) such that the upper zone's cool air spreads carried by the below-mentioned zone of hot air in the upper part of the room and drops down and Astadkonuner a piston action similar to directed narrowing air distribution. Apparatus according to claim 2, characterized in that the partition (20) and the intermediate disc (21) are placed so that a suitable relationship between the conditioning air (3) and the circulation air (9) in the supply air (11) is achieved. 4. Apparatus according to claim 2, characterized in that the apparatus is provided with a manual or automatically actuable control means (16) for the air flow, whereby the conditioning air flow (3) through the apparatus can be controlled. 5. Apparatus according to claim 2, characterized in that the air flow through the apparatus is controlled by either stepwise or steplessly changing the speed of the fan (17). 6. Apparatus according to claim 2, characterized in that the effect of the heater (19) is controlled either stepwise or steplessly.