AU2017100215A4

AU2017100215A4 - Improved air conditioning system

Info

Publication number: AU2017100215A4
Application number: AU2017100215A
Authority: AU
Inventors: Bruce HENSHALL; David Henshall; Andrew KARAS
Original assignee: Dometic Sweden AB
Current assignee: Dometic Sweden AB
Priority date: 2014-03-06
Filing date: 2017-02-23
Publication date: 2017-03-23
Anticipated expiration: 2023-03-06
Also published as: AU2016101949B4; EP3113965A1; AU2016101949A4; AU2015226832A1; CN106470856A; EP3113965A4; DE202015009786U1; WO2015131235A1; AU2015226832B2

Description

-1 - 2017100215 23 Feb 2017

IMPROVED AIR CONDITIONING SYSTEM FIELD OF THE INVENTION

[0001] The present invention relates generally to air conditioning systems and in particular to air conditioning systems that are located in a compact slim line housing that is suitable for use in a confined area.

BACKGROUND TO THE INVENTION

[0002] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

[0003] Air conditioning systems are commonly used in order to make an environment more pleasing to occupants. This is particularly relevant when they’re our options in a confined space, such as a caravan, mobile home or other recreational vehicle.

[0004] As used herein, the term ’’recreational vehicles” refers to motor homes, recreational vans, and other similar vehicles. Each of these has relatively confined spaces for the occupants to reside in and, as due to the nature of their use it is often that such vehicles are often used with a number of people, such as couples or families.

[0005] These recreational vehicles are built to suit a particular purpose so that there is a need to keep the weight of the vehicle to a minimum so that driving or towing them does not create too much of an impact on overall efficiency of the vehicle itself.

[0006] Conventional recreational vehicles have air conditioning systems that are built into the vehicle in some manner. For example, the air conditioning unit can be installed into the floor or roof and direct air around the interior cabin of the vehicles so that conditioned air is then provided to a particular area for the occupants.

[0007] Conventional air conditioning systems used in recreational vehicles are generally not as powerful as those that are used in domestic static dwellings due to the need to keep the weight and overall size of the air conditioning in the recreational vehicle as low as possible. If an air conditioner unit has a simple conventional outlet, that is with a short path between the cooling chamber and the outlet, this results in a very small zone immediately -2- 2017100215 23 Feb 2017 adjacent to the outlet to which the conditioned air is supplied. For example, when an air conditioner is set to cool, the cooling zone around the outlet is relatively small and the efficiency of cooling, that is how large the cooling zone extends is proportional to the power of the air conditioner and so the effect reduces with respect to distance from the outlet.

[0008] Such a conventional system though may be appropriate in mild conditions when the variations of weather are minor, however it is during the hot summer months that such conventional air conditioning units fail to act to cool the interior cabin section of the recreational vehicle and so are inadequate.

[0009] Others had meet this shortcoming by making use of a ducting system in order to better deliver conditioned air to the occupants in a very targeted manner.

[0010] For example, as shown the figure 1, the air conditioning system 1 includes a number of ducts 2a and 2b that distribute the conditioned air around to various predefined outlets inside the interior of the vehicle. The length and size of the ducting can be varied to a certain degree to suit installation however the ducts must be of a minimum size to ensure that they are able to deliver a suitable volume of air to any one particular outlet so that the conditioned air can have some effect on the occupants.

[0011] The problem with such systems is that the ducts need to be quite large with respect to the area that they are being installed in taking into consideration that the walls of a recreational vehicle are relatively thin compared to a domestic wall. This then limits the size of the ducting that can be placed within the wall space or roof space of the recreational vehicle, and in many cases results in undersized ducting being used which reduces the air flow and air conditioner capacity.

[0012] To compensate for the use of ducts presently used in many installations, some manufacturers have increased the roof space in the recreational vehicle however this results in either a slight lowering of the interior ceiling, which is not aesthetically pleasing or alternatively it can result in an increase in the outer roof height, which is the overall height of the recreational vehicle. Again, this is not desirable due to the need to keep the overall height of the recreational vehicle as low as possible to ensure that it is able to meet certain standards.

[0013] It is an object of the present invention to overcome, or at least substantially ameliorate, the disadvantages and shortcomings of the prior art. -3- 2017100215 23 Feb 2017 [0014] It is an object of the present invention, in at least one preferred form, to provide an air conditioning system for use in a recreational vehicle that provides a greater distribution of air without the need for ducting.

[0015] Further advantages of the present invention will become apparent from the following description, taking in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.

SUMMARY OF THE INVENTION

[0016] According to one aspect, the present invention provides an air conditioning system for a vehicle having a roof, the air conditioning system having at least one air conditioning unit, including at least one centrifugal fan, at least one return air entry port, at least one outlet port, at least one heat exchange coil operatively connected to a compression refrigeration system, a first chamber formed by the at least one heat exchange coil substantially surrounding the at least one centrifugal fan, the at least one centrifugal fan operable to draw in indoor air via the return air entry port and tangentially eject the indoor air in a substantially horizontal plane, a second chamber forming a conditioned air flow plenum, said plenum having a conditioned air flow path to direct the indoor air flow through the least one heat exchange coil, and out through at least one outlet port, wherein said at least one outlet port is configured to direct the air flow path in a substantially horizontal plane adjacent to the roof.

[0017] According to one aspect, the present invention comprises an air conditioning system for a vehicle having a roof, the air conditioning system having at least one air conditioning unit, including at least one centrifugal fan, at least one return air entry port, at least one outlet port, at least one heat exchange coil operatively connected to a compression refrigeration system, a first chamber formed by the at least one heat exchange coil substantially surrounding the at least one centrifugal fan, the at least one centrifugal fan operable to draw in indoor air via the return air entry port and tangentially eject the indoor air in a substantially horizontal plane, a second chamber forming a conditioned air flow plenum, said plenum having a conditioned air flow path to direct the indoor air flow through the at least one heat exchange coil, and out through an at least one outlet port, wherein said at -4- 2017100215 23 Feb 2017 least one outlet port is configured to direct the air flow path in a substantially horizontal plane adjacent to the roof.

[0018] In preference, the fan is located directly above the return air port.

[0019] In preference, the at least one outlet port is configured to direct the air flow path in a substantially horizontal plane adjacent to the roof by at least one louver.

[0020] In preference, the at least one louver is pivotable.

[0021] In preference, the at least one louver is pivotable between an open position and a closed position.

[0022] In preference, at least one directional vane is positioned in the first chamber adjacent to the at least one centrifugal fan.

[0023] In preference, the second chamber redirects the air flow path from the first chamber in a downward direction and towards the at least one return air entry port and then redirecting the airflow path by way of air flow guides outwards and away from the at least one return air entry port.

[0024] Preferably, the air flow path is “S”-shaped.

[0025] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] By way of example, an embodiment of the invention is described more fully hereinafter with reference to the accompanying drawings, in which: [0027] Figure 1 is an example of a prior art air conditioning system, [0028] Figure 2 is a perspective view of an air conditioner constructed in accordance with the present invention, - 5- 2017100215 23 Feb 2017 [0029] Figure 3 is a horizontal cross sectional perspective view of figure of an air conditioner constructed in accordance with the present invention, [0030] Figure 4 is side cross sectional view of the present invention, [0031 ] Figure 5 is an exploded view of the lower plenum assembly, [0032] Figure 6 is a plan view of the present invention showing the return air entry port and the air out let ports, [0033] Figure 7 is a cross sectional view of Figure 6 along A-A; [0034] Figure 8 is the cross section view of Figure 6 along B-B showing the path of the air entering into the return air entry port, [0035] Figure 9 is a cross section view of the present invention showing the air paths through the interior of the present invention.

DETAILED DESCRIPTION

[0036] With reference to figure 2, the roof top air conditioner 5 of the present invention is located on a rooftop 7 of a vehicle (not shown), which may be a caravan, motor home, trailer or similar. As used herein, the term vehicle is intended to encompass all such motorised and non-motorised vehicles.

[0037] The air conditioner 5 has an outer cover 10 having and openings 12 and 13 to allow for the entry and exit of outside air into the heat exchange area of the air conditioner.

[0038] Figure 3 shows a view of the air conditioner 5 with a portion of the outer cover 10 removed showing the fan 15 that draws outside air into the heat exchange area and then forces it out through openings 13. The compressor 18 can be of any commercially acceptable type and is preferably mounted in a horizontal position as shown. Operatively connected to the compressor 18 is a condenser 20 that substantially surrounds the fan 15. Air drawn in from the outside is then forced through the condenser 20 and through the condenser to cool the refrigerant. This cooled refrigerant then passes through an expansion valve and into the evaporator 25 to absorb heat from indoor air that passes over it. The refrigerant then returns back to the condenser 20 to once again be cooled then the condenser 20 and the evaporator 25 acts in unison as a heat pump. - 6- 2017100215 23 Feb 2017 [0039] The evaporator 25 is substantially surrounded by an evaporator cover 28 (top removed in figure 3), which can be made from any suitable material, such as polystyrene material for increased insulation effects. The enclosure or chamber formed by the evaporator cover 28 and the base 42 forms a plenum or chamber that acts to guide air being drawn in through the return air inlet port 32 by a fan 34 having an impeller rotated by a fan motor 36. So as to straighten out the airflow as it passes through the return air inlet port 32 a flow straightener 38 is located between the return air inlet port 32 and the fan 34. A filter 50 provides filtration of the return air path.

[0040] The fan 34 then ejects or forces the indoor air tangentially in a substantially horizontal manner so that it then is forced into and around the evaporator 25. As mentioned, the fan generates an air flow that is horizontal. In order to achieve this flow, the fan of the present embodiment is a centrifugal fan 34 positioned upstream of the evaporator 25. However, it should be appreciated any type of fan that achieves a horizontal flow would be suitable according to the invention. As the evaporator 25 substantially surrounds the centrifugal fan 34 there is a significant increase in the cooling effect upon the indoor air that has been drawn in compared to conventional systems where the evaporator may only surround a small portion of the fan.

[0041] Once the indoor air has been cooled, or conditioned, by passing through the evaporator 25 it enters a further chamber formed by the cover 28 and the base portion 42, the conditioned air flow plenum, which directs the conditioned air along path 31 through an opening 33 that directs the air flow down and back towards the return air inlet port 32 where it is then further directed down and away from the air inlet port 32, ultimately ejecting the conditioned air through a louver 45 of the outlets 40 shaped to direct the outgoing air stream substantially horizontally, adjacent to the interior roof surface 46. The air path 31 is an “S”-shape which provides for a more compact arrangement of the openings 40 relative to the return air inlet port 32, however a more elongated “S”-shaped port may be employed although this would require a larger plenum cover 48 or alternatively a larger sized opening into which the air conditioning unit would reside.

[0042] By forcing the air path in this manner it was unexpectedly shown that the air flow so created traveled out a substantial distance away from the air outlets 40 so that it was able to cool areas well away from the air outlets 40 without requiring the need for any ducting to direct the air flow. 2017100215 23 Feb 2017 - 7- [0043] The plenum cover 48 has a number of air outlets 40 surrounding the return air inlet port 32. Each air outlet 40 has a louver, or air guide, 45 that is able to rotate about its horizontal axis so that it can move between an open and closed position. In figure 7, louver 45a is in a closed position such that no air can pass out through the opening 40a and louver 45b is in an open position. Figure 8 shows both louvers 45a and 45b in an open position. Each of the louvers 45 can be either manually or remotely adjusted.

[0044] The present invention also provides the unexpected benefit of better managing the flow of air back into the return air inlet port 32. One of the known problems with traditional vehicle air conditioning units is that conditioned air is often ejected relatively closely to the return air inlet port without having travelled far enough to cool the air space generally or the occupants. Whilst air conditioning systems that use ducts to take the conditioned air away from the return air inlet port partially address this problem, they introduce the complexity of having ducting work in the roof space of the vehicles cabin area as well as reducing the capacity of the air conditioner due to the decrease in air flow and thermal losses through the ducts.

[0045] The system of the present invention, which induces a substantial flat layer of airflow adjacent to and along the interior roof surface, allows the conditioned air to travel further away from the return air inlet port 32 and so the air being drawn into the return air inlet port 32 less likely to be recently conditioned air, which greatly enhances the effect of the conditioned air within the vehicles cabin by ensuring that the conditioned air is being used effectively to take heat out of the vehicle.

[0046] Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures can be made within the scope of the invention, which is not to be limited to the details described herein but it is to be accorded the full scope of the appended claims so as to embrace any and all equivalent devices and apparatus.

Claims

CLAIMS:

1. An air conditioning system for a vehicle having a roof, the air conditioning system having at least one air conditioning unit, including at least one centrifugal fan, at least one return air entry port, at least one outlet port, at least one heat exchange coil operatively connected to a compression refrigeration system, a first chamber formed by the at least one heat exchange coil substantially surrounding the at least one centrifugal fan, the at least one centrifugal fan operable to draw in indoor air via the return air entry port and tangentially eject the indoor air in a substantially horizontal plane, a second chamber forming a conditioned air flow plenum, said plenum having a conditioned air flow path to direct the indoor air flow through the least one heat exchange coil, and out through at least one outlet port, wherein said at least one outlet port is configured to direct the air flow path in a substantially horizontal plane adjacent to the roof.
2. The air conditioning system of claim 1, further characterized in that the fan is located directly above the return air port.
3. The air conditioning system of claim 2, further characterized in that the at least one outlet port is configured to direct the air flow path in a substantially horizontal plane adjacent to the roof by at least one louver.
4. The air conditioning system of claim 3, further characterized in that the at least one louver is pivotable.
5. The air conditioning system of claim 4, further characterized in that the at least one louver is pivotable between an open position and a closed position.
6. The air conditioning system of claim 5, further characterized in that the at least one directional vane is positioned in the first chamber adjacent to the at least one centrifugal fan.
7. The air conditioning system of any one of claims 1 -6, further characterized in that second chamber redirects the air flow path from the first chamber in a downward direction and towards the at least one return air entry port and then redirecting the airflow path by way of air flow guides outwards and away from the at least one return air entry port.
8. The air conditioning system of claim 7, further characterized in that air flow path is “S”-shaped.