FORM 2
THE PATENTS ACT 1970 (39 of 1970) & THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
An air-conditioning system for a vehicle
APPLICANTS


TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
I. Kevin, Maneesh Arora & Senthilkumar Natrajan
all Indian national of TATA MOTORS LIMITED
an Indian company having its registered office at
Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India

PREAMBLE TO THE DESCRIPTION
The following specification describes the invention and the manner in which it is to be performed.


FIELD OF INVENTION
This invention is related to improvement of air conditioning system in automobiles and more particularly to ensure proper condensate management system from the evaporator unit in all conditions.
BACKGROUND OF INVENTION
In air conditioning system the moist air flows over the evaporator coil and get cooled air which is then blown in to the cabin for human comfort. The temperature of the air is reduced and at the same time the moisture content in the air also gets condensed while the coil attains the dew point temperature of air. When this condensed water accumulates inside the air-conditioning, it creates problems like water splashing into the cabin, short circuiting in the electrical system, irritable odor, etc. So, the condensate needs to be removed from the unit completely as and when it is formed. Usually in the air conditioning system, a single drain pipe is being used to drain the water from the air condition system. In usual practice, the evaporator coil and the blower system will be mounted in the same horizontal plane in which single water draining system serves the purpose. Due to the packaging constraints it is always not possible to locate the evaporator and blower at the same level. Hence if the evaporator is located at higher level than that of the blower then there is an possibility of the non drained water accumulated in the tray, of splashing from the tray during jerk or turn of the vehicle into the path of the air sucked from the opening near the condenser into blower and in turn inside the cabin. This accumulated or splashed water in the path of air flow should be drained off and should not be allowed to be accumulate any where in the path due to possibility of splashing it in the cabin. The flow system should be efficiently managed to achieve good flow management in such circumstances.
OBJECTS OF INVENTION
The main object of the invention is an automobile air conditioning system wherein the evaporator is located at higher level than the blower.

Another object of this invention is the provision of effective condensate flow management system when the blower and evaporator coil are placed at different plane.
Yet another object of this invention is to provide a secondary drain hose system for condensate flow management from the air conditioning system.
STATEMENT OF INVENTION
Accordingly the present invention discloses an air-conditioning system comprising;
an evaporator assembly;
a blower assembly;
at least one duct connecting said evaporator assembly to the said blower assembly;
and
at least one drain pipe connected to said duct to drain water in the duct to avoid
splashing of water in the cabin.
BRIEF DESCRIPTION OF THE DRAWINGS
The original features of the system can be understood by the following diagrams. Figure 1 illustrates the actual mounting of the heating ventilation and air conditioning in the vehicle.
Figure 2 depicts the condensate flow management system.
Figure 3 depicts the cross section area of the secondary drain hose system.
DETAILED DESCRIPTION OF INVENTION
Heating Ventilation and Air conditioning (HVAC) Configuration
The designed HVAC consists of two separate assembly parts in order to overcome the
packaging constraint in the vehicle. The details of the two assemblies are the
following

1. Blower assembly - This assembly 2 is shown in the fig. 1 mounted on the floor 1 of the vehicle, consisting of blower motor 6, heater core assembly 15, chest and demist outlet 3, leg outlet ducts 4 and kinematics 5 to operate various flap arrangement. The kinematics 5 may be manually operated (cable or electric) or completely fully automatic.
2. Evaporator assembly - This assembly is shown in fig. 1 consisting of evaporator coil 13, cut for fresh air 12 and recirculation air 11. The assembly is enclosed in a casing 9 and to the front side of the casing; the primary drain pipe 10 is fitted and mounted on the firewall.
The evaporator assembly is located at higher level than the blower assembly. There exists a suction duct 8 which connects evaporator assembly casing 9 and the blower assembly 2. A secondary drain pipe 7 is fitted at the end of the suction duct to ensure proper water draining from the HVAC system.
In circumstances as shown in fig.l where the evaporator assembly is located above the plane of blower system and connected by a duct (8), there exists a probability of condensate entering in to the blower system 6 particularly in worst situation like vehicle tilt condition. In order to ensure, proper drainage of condensate from the HVAC system in all circumstances, a secondary water draining system 7 has been located in the suction duct 8. Secondary drain pipe system implemented in the HVAC system to ensure proper condensate management from the evaporator unit during vehicle tilt condition.
A two drain pipe system for a HVAC unit in the vehicle is located. The first drain outlet (primary) 10 is located at the lower side of the front portion on evaporator casing. The second drain outlet (secondary) 7 is located at the lowest point of the suction duct (8) which connects the evaporator coil and the blower system. From the outlet the drain pipe is connected and let outside the vehicle. During the vehicle tilt condition, the condensate will flow through the suction duct from the evaporator coil in to the blower system. In order to avoid the entry of condensate into the blower

assembly system this secondary drain pipe is designed right at the lowest point of the suction duct to ensure proper water drainage system.
Reference to figure 2 and 3, the flow of the condensate from the HVAC unit to outside the vehicle is explained. It clearly depicts the condensate flow management during the Air conditioner is ON condition. When the moist air flows over the evaporator coil, the condensate forms as the coil reaches air dew point temperature. During AC ON condition, the primarily the condensate water drains through the primary drain pipe. When the vehicle moves on a gradient or in an inclined condition the draining through the primary drain pipe become ineffective and the spill over of condensate will enter the suction duct which will be collected in the drain sump 14 provided at the end of the suction duct and get drained through the secondary drain pipe. Thus the water entry in to the blower system is avoided by provision of secondary drain pipe 7.
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.


WE CLAIM
1. An air-conditioning system comprising;
an evaporator assembly;
a blower assembly;
at least one duct connecting said evaporator assembly to the said blower assembly; and
at least one drain pipe connected to said duct to drain water in the duct to avoid splashing of water in the cabin.
2. The air-conditioning system as claimed in claim 1 wherein said blower assembly is located at same or lower level than that of said evaporator assembly.
3. The air-conditioning system as claimed in claim 1 wherein said drain pipe connected to a drain sump located at lowest point of said duct.
4. The air-conditioning system as claimed in claim 1 wherein said blower assembly is mounted on floor of a vehicle.
5. The air-conditioning system as claimed in claim 1; wherein said drain pipe is a secondary drain pipe in addition to a preliminary pipe mounted to the evaporator
assembly.
6. The air-conditioning system substantially as herein above described and as
illustrated in accompanying drawings.
Dated this 30th day of March 2009
TATA MOTORS LIMITED By their Agent & Attorney

Karuna Goleria of DePENNING & DePENNING