GB2381855A

GB2381855A - Self contained air conditioning unit

Info

Publication number: GB2381855A
Application number: GB0220503A
Authority: GB
Inventors: Callum Grant
Original assignee: KOOLTECH Ltd
Current assignee: KOOLTECH Ltd
Priority date: 2001-09-11
Filing date: 2002-09-04
Publication date: 2003-05-14
Also published as: GB0220503D0; GB0121895D0

Abstract

A self contained air conditioning unit 10 comprises a casing 18 having a condenser section 24 and an evaporator section 26 divided by a thermally insulated partition wall 28. The condenser section 24 comprises a condenser heat exchanger 30 having a fan disposed behind for drawing in cool outside air through an inlet 42 to an outlet 44 adjacent a compressor 32 so that the air passes over the compressor to help keep it cool and is exhausted outside as warm air, and an electronic circuit board connected to an infrared sensor 38 and a reversing valve 40. The evaporator section 26 comprises an evaporator heat exchanger 34 having a fan 36 disposed behind for drawing in warm air from a room through an inlet 46 and an outlet 48 located alongside the inlet 46 and behind the condenser heat exchanger 30 for exhausting cool dehumidified air into the room. The inlets and outlet may have louvred openings (22, fig 1) and the unit may have filters to remove particulates. The infrared sensor 38 is used to remotely control the operating cycle of the unit 10. The unit 10 may be a heating unit by reversing the flow of refrigerant or being provided with an electrical heating element.

Description

AIR CONDITIONING UNIT The present invention relates to air conditioning apparatus. In particular, the invention relates to air conditioning apparatus which is of relatively compact dimensions, and may be accommodated in areas of restricted extent.

Rising levels of affluence and generally warmer summers, together with an increase in traffic noise discouraging householders to open windows, have led to an increase in demand for domestic air conditioning in the United Kingdom and other countries. Some of these factors have also led to an increase in the prevalence of conservatories and similar constructions in domestic dwellings. These structures, made as they are with extensive areas of glass, are intended to trap heat from sunlight. This makes such constructions particularly prone to overheating in direct sunlight when outside temperatures rise above typical levels. Many conservatories would thus benefit from installation of domestic air conditioning units.

However, conventional air conditioning units present a number of problems for installation generally, and in conservatory structures in particular. Generally, air conditioning units consist of an evaporator unit, through which warm air from a room is drawn, and in which a refrigerant fluid is caused to evaporate and thereby cool

the air, the cooled air being returned to the room; and a condenser unit, which warms environmental air by transferring heat from compressed refrigerant fluid. The evaporator and condenser units are connected by a refrigerant fluid circuit incorporating a compressor, so causing heat to be transferred from the room to the external environment.

Typical air conditioning units comprise separate evaporator and condenser subunits, which for efficient and reliable operation must be installed, connected, and charged with refrigerant by specialist engineers. This requirement therefore increases the cost, time, and complexity of installing air conditioning, which may discourage domestic users from installing such a system.

Self-contained air conditioning units are known; however, these are typically relatively large and bulky, and so may be both visually and physically intrusive within a room, protruding some distance either in to or out of the room.

Conservatories also impose particular restrictions on the type of air conditioning units which may be installed therein: the large window area of a conservatory tends to restrict the available wall area through which an air conditioning unit may be fitted. Modern conservatories are generally built (in the United Kingdom at least) with "dwarf" walls of eight standard bricks in height, or around

600 mm. The depth of a conventional conservatory wall is also restricted, being around 265 mm, such that typical self-contained air conditioning units will protrude some distance into the room, or out from the room, which can be aesthetically displeasing as well as physically intrusive.

It is among the objects of embodiments of the present invention to obviate or alleviate these and other disadvantages of conventional air conditioning units. It is further among the objects of embodiments of the present invention to provide an air conditioning unit of restricted dimensions, suitable for installation in restricted areas.

According to the present invention, there is provided a substantially self-contained air conditioning unit comprising : a casing having a length, height, and depth, the length being greater than the height; evaporator and condenser sections located within the casing, each section comprising a heat exchanger, an air inlet and air outlet, and means for drawing air over the heat exchanger, the sections being substantially isolated to prevent airflow therebetween; and compressor means for compressing and circulating refrigerant fluid between the evaporator and condenser sections; wherein the evaporator and condenser heat exchangers are spaced lengthwise from one another along the length of

the casing.

For clarity,"lengthwise"as used herein refers to "along the length axis", while analogously"depthwise" refers to"along the depth axis". The depth axis is that axis extending perpendicular to, and through, a wall in which the air conditioning unit is to be installed. All "through the wall"air conditioning units will therefore have a well-defined depth axis. The length and height axes of the air conditioning unit run parallel to a wall in which the unit is to be installed; it will be apparent to the skilled person that the direction of the length and height axes may be interchanged without departing from the scope of the invention, so allowing the air conditioning unit of the present invention to be installed in a variety of restricted areas.

This arrangement allows the heat exchangers to be nonoverlapping depthwise along the casing, which thus allows the casing to have less depth than conventional air conditioning units. The air conditioning unit of the present invention can therefore be installed in a restricted depth, such as the depth of a brick cavity wall, which may form a conservatory wall, without protruding excessively therefrom. The elongate form of the air conditioning unit is particularly suited to installation in a conservatory wall beneath a window. An air conditioning unit according to the present invention may be constructed

with a cooling capacity of over 4 kW while nonetheless fitting comfortably within a volume of 1000 mm (1) x 450 mm (h) x 300 mm (d), which dimensions allow the unit to be installed substantially within a conservatory wall having a height of 600 mm and a depth of 265 mm.

Further, the self-contained nature of the apparatus allows the apparatus to be supplied ready-charged with refrigerant fluid, such that installation of the apparatus requires only electrical connection, or even merely plugging the apparatus into a mains electricity socket. The air conditioning unit thus does not require the presence of skilled personnel for installation, so leading to reductions in the cost and time for installation.

Preferably the apparatus comprises a partition dividing the evaporator and condenser sections. Preferably the partition is thermally insulated, to prevent unwanted heat transfer between the evaporator and condenser sections.

Preferably either or both of the sections provide the air inlet substantially lengthwise adjacent to the air outlet; this construction will tend to make full use of the available length of the air conditioning unit while not increasing the depth or height. The arrangement also allows the heat exchanger served by the air inlet to occupy a larger surface area of the casing than would be the case if the inlet and outlet were not lengthwise adjacent, so

providing greater efficiency of heat exchange.

Preferably the air outlet of one or both of the sections is spaced depthwise from, and overlapping lengthwise with, the heat exchanger of the other section. That is, the air outlet is located at the same length along the casing as the heat exchanger of the other section, although at a different depth within the casing. With conventional air conditioning units, there may be some "wasted space" located depthwise of the heat exchangers, since the heat exchangers need not fill the whole depth of the casing. The arrangement of the present invention thus allows the outlet of one of the sections to occupy this "wasted"depth by locating the outlet at the same length along the unit as the heat exchanger of the other section.

Thus, the air conditioning unit may be made more compact depthwise than conventional units.

Preferably the air drawing means comprises one or more fans, or the like.

Preferably one or more of the air inlets and/or one or more of the air outlets are covered with louvres or the like.

Preferably the unit further comprises one or more air filters disposed within the casing, to filter particulates and other contaminants from air passed through the unit.

Preferably the unit further comprises control means for controlling the operation of the unit; for example, an

electronic processor may be used to regulate the cycles of operation of the compressor and air drawing means.

Preferably the control means is programmable, to selectively operate two or more different cycles of operation. The control means may be user-programmable, or may be pre-programmed with two or more cycles of operation by the manufacturer or supplier. Preferably the control means is remotely operable by a user; for example, the control means may be provided with an infra-red or other signal receiver, which may be operated with a suitable remote control.

Preferably the unit further comprises means for selectively reversing the flow of refrigerant fluid through the evaporator and condenser sections. This allows the unit to be operated in reverse, to heat a conservatory in the winter, for example, if desired. The unit may instead or in addition comprise heating means, such as an electrical heating element, for heating air to be passed through one or both of the air outlets.

These and other aspects of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure 1 shows an external view of an air conditioning unit in accordance with an embodiment of the present invention, fitted into a conservatory wall; and Figure 2 shows an internal view of the air

conditioning unit of Figure 1.

Referring to the Figures, these show a self-contained air conditioning unit 10 in accordance with one embodiment of the present invention. Figure 1 shows the unit 10 embedded in a wall 12 of a conservatory. The wall 12 itself is of conventional construction, and is thus eight bricks or 600 mm in height, above which a window sill and frame 14 and a window 16 are located. The wall 12 is of double wall cavity construction, with two layers of brickwork, and is 260 mm deep.

The air conditioning unit 10 comprises a metal casing 18, which is 1000 mm in length, 450 mm in height, and 300 mm in depth. The height of the casing 18 is slightly less than that of six bricks of the wall 12, so allowing the unit 10 to be fitted snugly into a hole formed in the wall 12 without requiring bricks to be cut lengthwise, and with a layer of sealant 20 located between the casing 18 and the adjacent brick runs. Both the inner and outer faces of the casing 18 are provided with a louvred opening 22, which opens into an air inlet and outlet from the interior of the air conditioning unit 10.

The unit 10 may either be retrofitted to an existing wall, or may be incorporated into a wall during construction. The dimensions of the unit 10 allow a wall to be constructed with a suitable-sized gap left therein without complex cutting of bricks. In certain embodiments

of the invention, the wall may be constructed with a metal liner section incorporated therein of appropriate dimensions, and the air conditioning unit 10 may subsequently be simply inserted and secured into this liner section once construction is complete. A similar liner arrangement may of course also be used where the unit 10 is retrofitted to an existing wall.

The interior of the air conditioning unit 10 is shown in Figure 2. Within the casing 18 are provided a condenser section 24 and an evaporator section 26, divided by an insulated partition wall 28. The condenser section 24 includes a condenser heat exchanger 30, with a fan assembly located behind the heat exchanger 30. A refrigerant compressor 32 is located within the condenser section 24.

An air inlet 42 is located adjacent the heat exchanger 30, with a corresponding air outlet 44 located adjacent the compressor 32. Connected to the compressor 32 are an infrared control sensor 38 and a reversing valve 40, with an electronic control circuit board connected to these.

The evaporator section 26 includes an evaporator heat exchanger 34, and a fan assembly 36 located behind the heat exchanger 34. An air inlet 46 is located adjacent the heat exchanger 34, with a corresponding air outlet 48 located lengthwise alongside the inlet, at the same lengthwise location as the condenser heat exchanger 30, and spaced depthwise of the condenser heat exchanger.

The louvred openings 22 of the unit are located adjacent the air inlet 42,46 and outlet 44,48 of each section.

In use, the unit operates as follows. The refrigerant compressor 32 compresses refrigerant, so causing the compressed refrigerant to warm up, and pumps the refrigerant through the condenser heat exchanger 30. The fan of the condenser section 24 operates to draw cool air from the external environment in through the louvred openings 22 and inlet 42 of the condenser section 24, through the condenser heat exchanger 30, where the air gains heat from the refrigerant fluid, and out through the outlet 44 and louvred openings lengthwise alongside the condenser heat exchanger 30. The air passes over the compressor 32 before passing through the outlet 44, thereby serving to cool the compressor 32 and reduce the risk of overheating. The cooled refrigerant fluid is expanded, causing the fluid to cool and partially vaporise, before being circulated through the evaporator heat exchanger 34, as warm air from the conservatory is drawn in through the louvres and inlet 46 through the heat exchanger 34 where heat is transferred from the air to the refrigerant fluid, so cooling and dehumidifying the air and warming the refrigerant. The cooled dehumidified air is then passed out of the unit 10 via the outlet 48 into the conservatory to cool and condition the conservatory, while the warmed

refrigerant fluid is returned to the compressor 32.

The infra-red sensor 38 is arranged to detect signals transmitted thereto by an infra-red remote controller, and can instruct the electronic controller to alter the operating cycles of the air conditioning unit. Similarly, the reversing valve 40 may be actuated in response to signals from the remote controller, and the flow of refrigerant fluid around the unit reversed, so as to reverse the direction of heat transfer, should the user wish to heat the conservatory rather than cool it. A further variant is arranged to maintain the conservatory at a constant temperature, by reversing the flow of refrigerant fluid when necessary to balance the heat transfer between the conservatory and the environment.

Thus, it can be seen that the particular arrangement of the heat exchangers and air inlet and outlet vents of the present invention allow a self-contained air conditioning unit to be produced with substantially restricted height and depth, while retaining sufficient operating power to serve as a domestic air conditioning unit.

The air conditioning unit described herein may also be installed in a cavity wall with the length axis running vertically if desired, while retaining the capacity to be installed in a restricted area.

The skilled person will appreciate that various

modifications and variations may be made to the apparatus described herein without departing from the scope of the invention.

Claims

1. A substantially self-contained air conditioning unit comprising: a casing having a length, height, and depth, the length being greater than the height; evaporator and condenser sections located within the casing, each section comprising a heat exchanger, an air inlet and air outlet, and means for drawing air over the heat exchanger, the sections being substantially isolated to prevent airflow therebetween; and compressor means for compressing and circulating refrigerant fluid between the evaporator and condenser sections; wherein the evaporator and condenser heat exchangers are spaced lengthwise from one another along the length of the casing.

2. The air conditioning unit of claim 1, comprising a partition dividing the evaporator and condenser sections.

3. The air conditioning unit of claim 2, wherein the partition is thermally insulated to prevent unwanted heat transfer between the evaporator and condenser sections.

4. The air conditioning unit of any preceding claim,

wherein either or both of the evaporator and condenser sections provide the air inlet substantially lengthwise adjacent to the air outlet.

5. The air conditioning unit of any preceding claim, wherein the air outlet of either or both of the evaporator and condenser sections is spaced depthwise from, and overlapping lengthwise with, the heat exchanger of the other section.

6. The air conditioning unit of any preceding claim, wherein the air drawing means comprises one or more fans, or the like.

7. The air conditioning unit of any preceding claim, wherein one or more of the air inlets and/or one or more of the air outlets are covered with louvres or the like.

8. The air conditioning unit of any preceding claim, further comprising one or more air filters disposed within the casing, to filter particulates and other contaminants from air passed through the unit.

9. The air conditioning unit of any preceding claim, further comprising control means for controlling the operation of the unit.

10. The air conditioning unit of claim 9, wherein the control means is programmable, to selectively operate two or more different cycles of operation.

11. The air conditioning unit of claim 9 or 10, wherein the control means is remotely operable by a user.

12. The air conditioning unit of any preceding claim, further comprising means for selectively reversing the flow of refrigerant fluid through the evaporator and condenser sections.

13. The air conditioning unit of any preceding claim, further comprising heating means for heating air to be passed through one or both of the air outlets.

14. An air conditioning unit as described herein, and as illustrated in the Figures.