FORM 2
The Patents Act 1970
(39 of 1970)
AND
THE PATENTS RULES, 2005
COMPLETE SPECIFICATION (See Section 10; Rule 13)
TITLE OF THE INVENTION
“SINGLE ZONE HVAC UNIT OF VEHICLE CONVERSION TO DUAL ZONE HVAC UNIT AND METHOD THEREOF”
APPILICANT(S)
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 particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
[0001] The present disclosure relates to vehicular air-conditioning system, and more particularly related to a single zone HVAC unit conversion to a dual zone HVAC unit and method thereof.
BACKGROUND OF THE INVENTION
[0002] FIG. 1 illustrates a single zone HVAC unit of a vehicle, according to prior art. The conventional design of the single zone HVAC unit includes a plurality of ducts (1-4) in which a first and second ducts (1, 2) are provided at an upper portion (e.g., dashboard) of the vehicle, and a third and fourth ducts (3, 4) are provided at a lower portion (e.g., leg side) of the vehicle, wherein the first and third ducts (1, 3) are configured to provide a volume of the air in the rear-seat compartment of the vehicle through rear vents, and the second and fourth ducts (2, 4) are configured to provide a volume of the air through dashboard vents and in the leg room of first row. The volume of the air is flowed through rear-seat compartment of the vehicle through a rear duct (5).
[0003] The conventional design of the single zone HVAC unit does not provide an option to front and rear-seat passengers to set the temperature of the front-seat compartment and the rear-seat compartment separately. Due to difference in solar ray’s intensity from front and side glasses of the vehicle, the front and rear-seat passengers generally do not have agreement on common temperature setting for both the front-seat compartment and the rear-seat compartment. Hence single zone HVAC unit does not provide any provision to set different temperature as per requirement of the front-seat and the rear-seat passengers.

[0004] Alternately, conventional high end vehicles provides quad zone configuration to cater the need of having different temperature as per requirement of the front-seat and the rear-seat passengers. The quad zone configuration allows the temperature to be controlled independently by the front-seat and the rear-seat passengers. However such quad zone configuration uses additional HVAC unit in console which increases the overall cost of the air-conditioning system in the vehicle.
[0005] Hence there remains a need of an efficient design of the single zone HVAC unit to provide air flow in both the front-seat compartment and the rear-seat compartment independently.
OBJECT OF THE INVENTION
[0006] The principal object of the embodiment herein is to provide a single zone HVAC unit conversion to a dual zone HVAC unit and method thereof. A single HVAC unit is proposed for providing hot/cold air for both front and rear passengers as per passenger requirements (i.e. a design of a single HVAC unit is modified to convert it in a dual zone HVAC unit).
[0007] Another object of the embodiment herein is to provide a unique ducting arrangement in existing single zone HVAC unit to create front and rear compartment air flow. An upper right duct and a lower right duct (leg side) is configured to provide cold air and hot air respectively to a front-seat compartment through the side vents and central vents in the front compartments. A special routing is provided to upper left duct and lower left duct (leg side) to provide cold air and hot air respectively to a rear-side compartment.
[0008] Another object of the embodiment herein is to provide a create a front and rear dual zone (i.e. left and right side compartment) in a single zone

HVAC unit by proving a partition wall. The air mixing flaps in each left and right side compartments by splitting temperature mixing flaps for left and right side portion by means of partition wall. This provides uniform air mixing in each of the rear-seat compartment and the front-seat compartment.
SUMMARY OF THE INVENTION
[0009] In one aspect the object is satisfied by providing a Heating, Ventilation, and Air Conditioning (HVAC) unit for a vehicle including a passenger compartment having a front-seat compartment and a rear-seat part. The HVAC unit includes a plurality of ducts in which a first and second ducts of the plurality of ducts are provided at an upper portion of the vehicle, and a third and fourth ducts of the plurality of ducts are provided at a lower portion of the vehicle. The first and third ducts are configured to provide a volume of the air in the rear-seat compartment of the vehicle, and the second and fourth ducts are configured to provide a volume of the air in the front-seat compartment of the vehicle. Further, The HVAC unit includes temperature mixing flap/s to provide uniform air mixing in the front and rear-seat compartment of the vehicle. A partition wall is provided to split the temperature mixing flap into separate temperature mixing flaps for front and rear compartment.
[0010] In an embodiment, the first and third ducts are configured to provide the volume of the air in the rear-seat compartment of the vehicle through a rear duct (5).
[0011] In an embodiment, the second and fourth ducts are configured to provide the volume of the air in the front-seat compartment of the vehicle through a dashboard vent and a central vent of the vehicle.

[0012] In an embodiment, the rear duct is provided at the rear-seat compartment of the vehicle.
[0013] In an embodiment, the first duct is provided at a left side of the upper portion of the vehicle and the third duct is provided at the left side of the lower portion of the vehicle.
[0014] In an embodiment, the second duct is provided at a right side of the upper portion of the vehicle and the fourth duct is provided at the right side of the lower portion of the vehicle.
[0015] In an embodiment, the HVAC unit includes a front HVAC controller to control the volume and temperature of the air in the front-seat compartment through the second duct and the fourth duct, and a rear HVAC controller to control the volume and temperature of the air in the rear-seat compartment through the first duct and the third duct. The rear HVAC controller is controlled independent of the front HVAC controller.
[0016] In an embodiment, the rear HVAC controller is provided at a particular location in the rear-seat compartment of the vehicle.
[0017] In an embodiment, the HVAC unit comprises a blower disposed to induce the volume of the air into the front-seat compartment through the second duct and the fourth duct, and the volume of the air into the rear-seat compartment through the first duct and the third duct.
[0018] In another aspect the object is satisfied by providing a method for converting a single zone HVAC unit of a vehicle to a dual zone. The method includes providing a plurality of ducts in which a first and second ducts of the plurality of ducts are provided at an upper portion of the vehicle, and a

third and fourth ducts of the plurality of ducts are provided at a lower portion of the vehicle. Further, the method includes configuring the first and third ducts to provide a volume of the air in the rear-seat compartment of the vehicle, configuring the second and fourth ducts are configured to provide a volume of the air in the front-seat compartment of the vehicle, providing a temperature mixing flap to provide uniform air mixing in the front-seat compartment and the rear-seat compartment of the vehicle, splitting the temperature mixing flap by deploying a partition wall. The first temperature mixing flap chamber is configured to provide a volume of the air in the front-seat compartment of the vehicle. Similarly, the second temperature mixing flap chamber is configured to provide a volume of the air in the rear-seat compartment of the vehicle.
[0019] In an embodiment, the method includes controlling the volume of the air in the front-seat compartment using a front HVAC controller, and controlling the volume of the air in the rear-seat compartment using a rear HVAC controller. The rear HVAC controller is controlled independent of the front HVAC controller.
[0020] In an embodiment, the method includes providing the rear HVAC controller at a particular location in the rear-seat compartment of the vehicle.
[0021] In an embodiment, the method includes providing a blower disposed to induce the volume of the air into the front-seat compartment through the second duct and the fourth duct (4), and the volume of the air into the rear-seat compartment through the first duct and the third duct (3).
[0022] These and other aspects of the embodiment herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiment and

numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiment herein without departing from the spirit thereof, and the embodiment herein include all such modifications.
BRIEF DESCRIPTION OF DRAWINGS
[0023] The proposed HVAC unit is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiment herein will be better understood from the following description with reference to the drawings, in which:
[0024] FIG. 1 illustrates a single zone HVAC unit, according to prior art;
[0025] FIG. 2 illustrates a single zone HVAC unit converted to a dual zone HVAC unit, according to embodiment as disclosed herein;
[0026] FIG. 3 illustrates an anterior view of the dual zone HVAC unit, according to embodiment as disclosed herein; and
[0027] FIG. 4 illustrates a method for converting a single zone HVAC unit to a dual zone HVAC unit, according to embodiment as disclosed herein.
DETAILED DESCRIPTION
[0028] The embodiment herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiment that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiment herein. Also, the various embodiment described herein are not necessarily mutually exclusive, as some embodiment can be combined with one or more other embodiment to form new embodiment. The term “or” as used herein, refers to a non-exclusive or, unless otherwise indicated. The examples

used herein are intended merely to facilitate an understanding of ways in which the embodiment herein can be practiced and to further enable those skilled in the art to practice the embodiment herein. Accordingly, the examples should not be construed as limiting the scope of the embodiment herein.
[0029] The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiment presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another.
[0030] Referring now to the drawings, and more particularly to FIGS. 2-4, there are shown preferred embodiment.
[0031] FIG. 2 illustrates a single zone HVAC unit converted to a dual zone HVAC unit, according to embodiment as disclosed herein. The HVAC unit includes a plurality of ducts (1-4) in which a first and second ducts (1, 2) of the plurality of ducts (1-4) are provided at an upper portion of the vehicle, and a third and fourth ducts (3, 4) of the plurality of ducts (1-4) are provided at a lower portion of the vehicle, wherein the first and third ducts (1, 3) are configured to provide a volume of the air in the Rear-seat compartment of the vehicle, and the second and fourth ducts (2, 4) are configured to provide a volume of the air in the Front-seat compartment of the vehicle. The first duct (1) is provided at a right side (10) of the upper portion of the vehicle and the third duct (3) is provided at the right side (10) of the upper portion of the vehicle. The second duct (2) is

provided at a left side (9) of the upper portion of the vehicle and the fourth duct (4) is provided at the left side (9) of the upper portion of the vehicle.
[0032] The first and third ducts (1, 3) are configured to provide the volume of the air in the Rear-seat compartment of the vehicle through the vents in center of the driver and co-driver seats of the vehicle through a rear duct (5) facing towards rear seat.
[0033] The second and fourth ducts (2, 4) are configured to provide the volume of the air in the Front-seat compartment where (2) provides air to dashboard vents and (4) provides the air to the leg of front passenger/s.
[0034] FIG. 3 illustrates an anterior view of the dual zone HVAC unit, according to embodiment as disclosed herein. The HVAC unit includes an temperature mixing flaps (6) and (7) to provide required temperature of air to front-seat compartment and rear-seat compartment of the vehicle.
[0035] A partition wall (8) is provided to split the temperature mixing flap/s (6) and (7).
[0036] Further, the HVAC unit includes a front controller and a rear controller so as the passengers in front and rear seat can control the temperatures independently.
[0037] In an embodiment, the front HVAC controller is provided at dashboard for easily controlling of temperature by front-seat passengers in the front-seat compartment of the vehicle.
[0038] In an embodiment, the rear HVAC controller is provided at a particular location in the rear-seat compartment of the vehicle for easily

controlling of the temperature by rear-seat passengers For example, a separate control panel can be provided for rear-seat passengers to control the temperature settings.
[0039] Further, the HVAC unit includes a single blower disposed to induce the volume of the air into the Rear-seat compartment through the first duct (1) and the third duct (3), and the volume of the air into the Front-seat compartment through the first duct (2) and the third duct (4). It is to be noted that in the proposed HVAC unit, temperatures in the front-seat compartment and the rear-seat compartment can be controlled independently using a single HVAC unit and a single blower without providing additional HVAC unit but by providing partition in the front HVAC unit. As only one pair of heat exchanger (evaporator and heater) and single blower is used in the proposed invention, the cost of the proposed design of the air conditioning system is low and also does not affect the overall performance of the vehicle.
[0040] FIG. 4 illustrates a method for converting a single zone HVAC unit to a dual zone HVAC unit, according to embodiment as disclosed herein.
[0041] At step S1, the method includes providing a plurality of ducts (1-4) in which a first and second ducts (1, 2) of the plurality of ducts (1-4) are provided at an upper portion of the vehicle, and a third and fourth ducts (3, 4) of the plurality of ducts (1-4) are provided at a lower portion of the vehicle.
[0042] In an embodiment, the first duct (1) is provided at a left side (10) of the upper portion of the vehicle and the third duct (3) is provided at the left side (10) of the lower portion of the vehicle. The second duct (2) is provided at a right side (9) of the upper portion of the vehicle and the fourth duct (4) is provided at the right side (9) of the lower portion of the vehicle.

[0043] Unlike the conventional HVAC unit, a unique ducting arrangement in existing single zone HVAC unit to create front and rear compartment air flow. For example, an upper right duct and a lower right duct (leg side) is configured to provide cold air and hot air respectively to a front-seat compartment through the side vents and central vents in the front compartments. A special routing is provided to upper left duct and lower left duct (leg side) to provide cold air and hot air respectively to a rear-side compartment.
[0044] In an embodiment, a blower disposed to induce the volume of the air into the rear-seat compartment through the first duct (1) and the third duct (3), and the volume of the air into the front-seat compartment through the first duct (2) and the third duct (4).
[0045] At step S2, the method includes configuring the first and third ducts (1, 3) to provide a volume of the air in the rear-seat compartment of the vehicle. The first and third ducts (2, 4) are configured to provide the volume of the air in the front-seat compartment of the vehicle through a dashboard vent and a central vent of the vehicle.
[0046] At step S3, the method includes configuring the second and fourth ducts (2, 4) are configured to provide a volume of the air in the front-seat compartment of the vehicle. The second and fourth ducts (1, 3) are configured to provide the volume of the air in the rear-seat compartment of the vehicle through a rear duct (5).
[0047] At step S4, the method includes splitting temperature mixing flap/s to provide different air temperature in front and rear compartment of the vehicle.
[0048] At step S5, the method includes providing air to rear seat passengers through the left side of the temperature mixing zones.

[0049] At step S6, the method includes providing air to front seat passengers through the right side of the temperature mixing zones.
[0050] At step S7 the method includes controlling the volume and temperature of the air in the front-seat compartment using a front HVAC controller ; and
[0051] At step S8, the method includes controlling the volume of the air in the rear-seat compartment using a rear HVAC controller. The rear HVAC controller controls temperature of air independent of the front HVAC controller by the rear and front seat passengers as per the requirement. In an embodiment, the method comprising providing the rear HVAC controller at a particular location in the rear-seat compartment of the vehicle.
[0052] Thus the proposed invention provides a single zone HVAC unit conversion to a dual zone HVAC unit and method thereof. A single HVAC unit is proposed for providing hot/cold air for both front and rear passengers as per passenger requirements (i.e. a design of a single HVAC unit is modified to convert it in a dual zone HVAC unit).
[0053] The foregoing description of the specific embodiment will so fully reveal the general nature of the embodiment herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiment without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiment. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiment herein have been described in terms of preferred embodiment, those skilled in

the art will recognize that the embodiment herein can be practiced with modification within the spirit and scope of the embodiment as described herein.
[0054] List to reference numerals:

Sr. No. Description
1 First duct
2 Second duct
3 Third duct
4 Fourth duct
5 Rear duct
6 Temperature mixing flap
7 Temperature mixing flap
8 Partition wall
9 left side
10 right side
11 front HVAC controller
12 rear HVAC controller

We Claim:
1. A Heating, Ventilation, and Air Conditioning (HVAC) unit for a vehicle
comprising a passenger compartment having a front-seat compartment and
a rear-seat part, wherein the HVAC unit comprises:
a plurality of ducts (1-4) in which a first and second ducts (1, 2) of the plurality of ducts (1-4) are provided at an upper portion of the vehicle, and a third and fourth ducts (3, 4) of the plurality of ducts (1-4) are provided at a lower portion of the vehicle, wherein the first and third ducts (1, 3) are configured to provide a volume of the air in the Rear-seat compartment of the vehicle, and the second and fourth ducts (2, 4) are configured to provide a volume of the air in the Front-seat compartment of the vehicle; and
a partition wall (8) splitting the temperature mixing flap/s.
2. The HVAC unit as claimed in claim 1, wherein the first and third ducts (1, 3) are configured to provide the volume of the air in the rear-seat compartment of the vehicle through a rear duct (5).
3. The HVAC unit as claimed in claim 1, wherein the second and fourth ducts (2, 4) are configured to provide the volume of the air in the Front-seat compartment of the vehicle through dashboard vents and a central vent of the vehicle.
4. The HVAC unit as claimed in claim 3, wherein the rear duct (5) is provided at the rear-seat compartment of the vehicle.
5. The HVAC unit as claimed in claim 1, wherein the first duct (1) and the third duct (3) is provided at a left side of the vehicle.

6. The HVAC unit as claimed in claim 1, wherein the second duct (2) and the fourth duct (4) is provided at a left side of the vehicle.
7. The HVAC unit as claimed in claim 1, wherein the HVAC unit comprises:
a front HVAC controller to control the volume of the air in the front-seat compartment through the second duct (2) and the fourth duct (4); and
a rear HVAC controller to control the volume of the air in the rear-seat compartment through the first duct (1) and the third duct (3), wherein the rear HVAC controller is controlled independent of the front HVAC controller.
8. The HVAC unit as claimed in claim 7, wherein the rear HVAC controller is provided at a particular location in the rear-seat compartment of the vehicle.
9. The HVAC unit as claimed in claim 1, wherein the HVAC unit comprises a blower disposed to induce the volume of the air into the front-seat compartment through the second duct (2) and the fourth duct (4), and the volume of the air into the rear-seat compartment through the first duct (1) and the third duct (3).
10. A method for converting a single zone Heating, Ventilation, and Air
Conditioning (HVAC) unit of a vehicle to a dual zone, wherein the
method comprises:
providing a plurality of ducts (1-4) in which a first and second ducts (1, 2) of the plurality of ducts (1-4) are provided at an upper portion of the vehicle, and a third and fourth ducts (3, 4) of the plurality of ducts (1-4) are provided at a lower portion of the vehicle;
configuring the first and third ducts (1, 3) to provide a volume of the air in the rear-seat compartment of the vehicle;
configuring the second and fourth ducts (2, 4) are configured to provide a volume of the air in the front-seat compartment of the vehicle;

splitting the temperature mixing flap/s to allow creating two separate temperature mixing zones, left side of the temperature mixing zone to provide air to rear seat passengers and right side of the temperature mixing zone to provide air to front seat passengers.
11. The method as claimed in claim 10, wherein the first and third ducts (1, 3) are configured to provide the volume of the air in the rear-seat compartment of the vehicle through a rear duct (5).
12. The method as claimed in claim 10, wherein the second and fourth ducts (2, 4) are configured to provide the volume of the air in the front-seat compartment of the vehicle through a dashboard vent and a central vent of the vehicle.
13. The method as claimed in claim 12, wherein the rear duct (5) is provided at the rear-seat compartment of the vehicle.
14. The method as claimed in claim 10, wherein the first duct (1) is provided at a left side (10) of the upper portion of the vehicle and the third duct (3) is provided at the left side (10) of the lower portion of the vehicle.
15. The method as claimed in claim 10, wherein the second duct (2) is provided at a right side (9) of the upper portion of the vehicle and the fourth duct (4) is provided at the right side (9) of the lower portion of the vehicle.
16. The method as claimed in claim 10, wherein the method comprises:
controlling the volume of the air in the front-seat compartment using a front HVAC controller; and
controlling the volume of the air in the rear-seat compartment using a rear HVAC controller, wherein the rear HVAC controller is controlled independent of the front HVAC controller.

17. The method as claimed in claim 16, wherein the method comprising: providing the rear HVAC controller at a particular location in the rear-seat compartment of the vehicle.
18. The method as claimed in claim 10, the method comprising:
providing a blower disposed to induce the volume of the air into the front-seat compartment through the second duct (2) and the fourth duct (4), and the volume of the air into the rear-seat compartment through the first duct (1) and the third duct (3).