HVAC system for vehicle

1. A heating, ventilation, and air conditioning (HVAC) system for a vehicle, the HVAC system comprising:

a casing having an inlet and a plurality of outlets;

an evaporator disposed within the casing;

a heater core disposed behind the evaporator within the casing; and

an air mixing door disposed between the evaporator and the heater core,

wherein the heater core and a rear wall of the casing are spaced apart from each other by a first distance,

the evaporator and the heater core are spaced apart from each other by a second distance, and

the first distance is greater than the second distance.

2. The HVAC system according to claim 1 , wherein a ratio of the first distance and the second distance is from 1.3:1 to 1.5:1.

3. The HVAC system according to claim 1 , further comprising: a heat trap spaced apart from a rear surface of the heater core,

wherein the heat trap and the heater core are spaced apart from each other by a third distance so that a heat trap space is defined between the heat trap and the heater core.

4. The HVAC system according to claim 3 , wherein the heat trap includes a plate having a plurality of holes.

5. The HVAC system according to claim 3 , further comprising:

an upper support configured to support a top end of the heater core, and

a lower support configured to support a bottom end of the heater core,

wherein the upper support has a top sealing portion extending toward a top end of the heat trap, and the lower support has a bottom sealing portion extending toward a bottom end of the heat trap.

6. The HVAC system according to claim 5 , wherein a free end of the top sealing portion abuts on the top end of the heat trap, and

a free end of the bottom sealing portion abuts on the bottom end of the heat trap.

7. The HVAC system according to claim 5 , wherein the top sealing portion is disposed on the upper support to form a unitary one-piece structure, and

the bottom sealing portion is disposed on the lower support to form a unitary one-piece structure.

8. The HVAC system according to claim 5 , wherein the lower support has an air pocket configured to contain air, and

a top portion of the air pocket is partially opened to the heat trap.

9. The HVAC system according to claim 5 , further comprising: a first baffle having an extension portion extending from the upper support and an inclined portion extending obliquely downward from an end of the extension portion.

10. The HVAC system according to claim 9 , further comprising: a second baffle located below the first baffle,

wherein the second baffle has an extension portion extending from the heat trap, a downward inclined portion extending obliquely downward from an end of the extension portion of the second baffle, and an upward inclined portion extending obliquely upward from the downward inclined portion.

11. The HVAC system according to claim 1 , further comprising: an upper bypass passage and a lower bypass passage, which are divided by the heater core located in a downstream of the evaporator.

12. The HVAC system according to claim 11 , wherein the air mixing door comprises:

an upper air mixing door movably mounted between the upper bypass passage and an upper portion of the heater core and configured to control an air flow passing through the upper bypass passage; and

a lower air mixing door movably mounted between the lower bypass passage and a lower portion of the heater core and configured to control an air flow passing through the lower bypass passage.

13. The HVAC system according to claim 11 , further comprising:

an upper support configured to support a top end of the heater core; and

a first baffle having a first portion horizontally extended from the upper support and a second portion extended from the first portion toward a bottom wall of the casing,

wherein the first baffle is configured to inhibit a cooled air from flowing from the upper bypass passage toward a heat trap disposed in a rear side of the heater core.