FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
WINDOW AIR CONDITIONING SYSTEM AND A METHOD THEREOF;
BLUE STAR LIMITED, A COMPANY INCORPORATED UNDER COMPANIES ACT 1956, WHOSE ADDRESS IS KASTURI BUILDINGS, MOHAN T. ADVANl CHOWK, JAMSHETJI TATA ROAD, MUMBAI- 400 020 MAHARASTRA, INDIA
THE FOLLOWING SPECIFICATION
PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF THE INVENTION
The present invention relates to a window air conditioning system and a method thereof.
BACKGROUND OF THE INVENTION
A conventional window air conditioning system (100') as shown in Figure 1 generally comprises a body having a front portion (10') known as evaporator side and a rear portion (20') known as condenser side divided with a partition. The condenser (60') side portion comprises a compressor (70'), a condenser coil (not shown), a fan (65') for passing ambient air through the condenser coil (herein after referred to as condenser fan) and an expansion device (not shown) while the evaporator (50') side portion comprises an evaporator coil and a fan (55') for passing air to be cooled over the evaporator coil (herein after referred to as evaporator fan) working on Reverse Carnot cycle to extract heat from lower temperature and rejecting the same at higher temperature. Both the fans i.e. the condenser fan (65') and the evaporator fan (55') are mounted on opposite end of a single shaft which is driven by a single motor (not shown). In condenser side, the condenser is adapted on an outlet window of the body and the fan is arranged just before the condenser to suck ambient air from the windows provided and blow through the condensers to make the air conditioner compact.

The air flow path of condenser side of the conventional window air conditioning system is shown in Figure 1. As the condenser fan is just before the condenser, the area of the condenser generally center of the condenser before the fan hub of the condenser fan receives substantially less air for heat transfer as compared to rest area of the condenser resulting in the reduced effective area of the condenser for heat transfer.
Further the energy efficiency of the window air conditioning system largely depends on the Condensing side and Evaporating side temperatures. The Energy Efficiency of the product generally denoted by the term COP (Coefficient of Performance) and/or EER (Energy Efficiency Ratio). The Energy efficiency is calculated by a unit energy consumed for heat extraction from the designated space. Higher the difference between the condensing and evaporating temperatures lower the energy efficiency of the system. Hence there is need to reduce the Temperature difference for a given capacity of the system. Presently this is done by increasing the evaporator pressure and reducing the discharge pressure in the system. However, in actual application there are constraints to maximize the efficiency such as dimensions of the heat exchangers, which cannot be increased due to the cost, and air flow cannot be increased beyond certain point due to the noise level etc.

Further, in certain application due to space constraints, the differential temperature cannot be minimized beyond a certain point. Moreover, the air drawn from ambient by condenser fan passes over the compressor which may result in further increase in the air temperature prior to passing over the condenser.
Further, current conventional window type air conditioners are difficult to manufacture with a higher Bureau of Energy Efficiency (BEE) star ratings (COP - 3 and above) due to inherent design constraints. Further, conventional window air conditioning system is noisy. Also, the ambient air from outside contains dust particles and when the air is sucked in the system the performance of the system reduces severely as the dust particles enter the machinery within the system. Further for cleaning one has to remove of air conditioner from window and dismantle of the body is required for which a person skilled in the art is required. Therefore, there is need of window air conditioning systems which reduce the energy consumption and attain comfort conditions including low noise levels.
SUMMARY OF THE INVENTION
The objective of the present invention is to overcome the above mentioned shortcomings under the background art.

Accordingly, the present invention in one aspect provides a window air conditioning system comprising a body having a front portion and a rear portion divided with a partition along with at least one air inlet and an outlet for each portion, said body includes an evaporator with a fan for heat exchange and cooling air in an enclosed space, an evaporator fan for passing air over the evaporator, a condenser for condensing a refrigerant, a condenser fan to draw ambient air from the air inlet, a compressor for compressing the refrigerant, and an expansion device for controlling pressure arranged in order wherein the condenser is adapted at the air inlet to suck ambient air through the condenser for complete utilization of heat transfer area of the condenser.
According to one embodiment of the present invention, a condenser is adapted at each air inlet of rear portion by splitting for a rear portion having more than one inlet.
According to another embodiment of the present invention, the system may comprise a condenser at the air outlet of the condenser fan.
According to further embodiment of the present invention, the blower fan and the evaporator fan are driven by separate motors.
According to furthermore embodiment of the present invention, the system comprises, a controller to control the speed of each fan depending upon the ambient and comfort conditions respectively.

In second aspect, the present invention provides a window air conditioning system comprising a body having a front portion and a rear portion divided with a partition with atleast one air inlet and an outlet for each portion, a condenser, a blower for circulating air within a predetermined enclosed space, a compressor, and an evaporator fan orderly provided in the body wherein the evaporator fan and condenser fan are driven with separate motors to use total heat transfer area of the condenser.
In third aspect, the present invention provides a method of cooling of condenser side of the window air conditioning comprising steps of sucking air through the condenser in order to use total heat transfer area of the condenser of the window air conditioning system.
DESCRIPTION OF THE DRAWINGS:
The preferred embodiment of the present invention will now be described with reference to the accompanying drawings, which are given by way of example and are not to be taken as limiting in any way. The accompanying drawings are intended to make the invention easier to understand.
Figure 1 shows a window air conditioning system of the prior art;
Figure 2 shows a perspective view of a preferred embodiment of a window air
conditioning system of the present invention; and

Figure 3 shows top schematic view of the air conditioning system of the present invention shown in the Figure 2 without connections.
DESCRIPTION OF THE INVENTION
Accordingly, the present invention in general provides a window air conditioning system comprising a body having a front portion and a rear portion divided with a partition along with at least one air inlet and an outlet for both portion wherein an evaporator with a fan is provided for cooling air in an enclosed space, a condenser for condensing a refrigerant is adapted at the air inlet to draw cold air through the condenser for complete utilization of heat transfer area oi the condenser, a condenser fan to suck ambient air through the condenser, a compressor for compressing the refrigerant and an expansion device adapted orderly in the body.
According to the present invention, the condenser is adapted at each air inlet of the rear portion by splitting.
The present invention also in general provides a window air conditioning system wherein a condenser fan and an evaporator fan are driven by separate motors and controlled based one separate control modules. This allows arranging the condenser and condenser fan within the body in such a way that heat transfer area of the condenser can be substantially used totally.

The present invention also provides a method cooling of condenser side of the window air conditioning wherein ambient air is sucked through the condenser in order to use total heat transfer area of the condenser of the window air conditioning system.
Hereinafter, the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
Referring Figures 2 and 3 show a window air conditioning system (100) having a body (90) divided into front portion (X) and a rear portion (Y) with two air lets (30A, 306) and one air outlet (40) at the rear portion (Y) and one air let (50) and one air outlet (40) at the front portion (B).
As shown in Figures 2 and 3, the air conditioner has a split type condenser configuration and airflow path according to the present invention. The evaporator (50) is adapted by a known way before the inlet (10) of the front portion (X). The condenser (60) has split into two piece system (60A, 60B) adapted at the inlets (30A, 30B) and the condenser fan (65) is adapted at the air outlet (40) of the rear portion (Y) of the body (90). The split condensers (60A, 60B) are arranged in such a way that they surround the area of the condenser fan (65) for total utilization of the heat transfer area. Since, the condenser (60) is adapted at the inlets (30), the dust particles entering from outside are avoided at the first instant only. This helps greatly in improving the system performance.

According to the present invention, the condenser fan (65) and evaporator fan (55) are driven by separate motors (70, 80). The decoupling of evaporator and blower fan allows individual control of condenser fan (65) and evaporator fan (55). The speed of condenser fan (65) can be controlled on the parameters like ambient temperature and cooling load. The speed of the evaporator fan (55) can be controlled on the basis of comfort conditions and noise levels. This allows designer to design a low power, low noise, energy efficient evaporator motor and reduced capacity, low noise condenser motor along with complete utilization of heat transfer are of the condenser. This ultimately results in high overall efficiency of the air conditioner. Alternatively, the condenser fan and the evaporator fan can be adapted on the single shaft and driven by a single motor. According to the present invention, a condenser may be adapted at the air outlet of rear portion of the system.
The ambient air passes first over the condenser (60) as the fan (65) draws air through the condenser where heat transfer takes place between the air and the condenser (60) before entering the air conditioning system thus the condenser gets the cooler air as compared to the conventional system. The air conditioning system of the present invention requires low power, produces low noise, and is energy efficient.

While the invention has been described with respect to presently preferred embodiment, it will be understood that the invention can be applied to numerous forms of applications air-conditioning systems. Accordingly, the principles of the invention are not limited to the embodiment described. The invention is capable of certain modification and change without departing from the spirit of the invention.

We Claim:
1. A window air conditioning system comprising:
a body having a front portion and a rear portion divided with a partition along with at least one air inlet and an outlet for each portion; and
an evaporator cooling air in an enclosed space;
an evaporator fan for passing air over the evaporator;
a condenser for condensing a refrigerant;
a condenser fan to draw ambient air from the air inlet;
a compressor for compressing the refrigerant; and
an expansion device for controlling pressure adapted in order within the body to provide cooling in the enclosed space
wherein the condenser is adapted at the air inlet to draw ambient air through the condenser for complete utilization of heat transfer area of the condenser
2. The air-conditioning system as claimed in claim 1 wherein the condenser is
adapted at each air inlet of rear portion by splitting for a rear portion having
more than one air inlet.

3. The air-conditioning system as claimed in claim 1 wherein the system further comprises a condenser at the air outlet of the condenser fan.
4. The air-conditioning system as claimed in claim 1 wherein the blower fan and the evaporator fan are driven by separate motors.
5. The air-conditioning system as claimed in claim 4 wherein the system comprises a controller each for controlling speed of the condenser fan and evaporator fan depending upon the ambient and comfort conditions respectively.
6. The air-conditioning system as claimed in claim 6 wherein the speed of the condenser fan can be controlled on the parameters like ambient temperature and cooling load.

7. The air-conditioning system as claimed in claim 1 wherein the blower fan and the evaporator fan are driven by single motor.
8. A window air conditioning system comprising a body having a front portion and a rear portion divided with a partition with atleast one air inlet and an

outlet for each portion, a condenser, a blower for circulating air within a predetermined enclosed space, a compressor, and an evaporator fan adapted orderly in the body wherein the evaporator fan and condenser fan are driven with separate motors to use total heat transfer area of the condenser.
9. A method of cooling of condenser side of a window air conditioning system, the air-conditioning system comprising a body having a front portion and a rear portion divided with a partition along with at least one air inlet and an outlet for each portion, an evaporator with a fan, a condenser for condensing a refrigerant, a condenser fan to draw ambient air from the air inlets, a compressor for compressing the refrigerant; and an expansion device for controlling pressure, the method comprising step of:
sucking air through the condenser by adapting condenser at the air inlet in order to use total heat transfer area of the condenser of the air conditioning system.

10. The method as claimed in claim 9 wherein the sucking of air may alternatively be achieved by driving condenser fan and evaporator fan with separate motors.