Casing for a heat exchange system

1. A casing for a heat exchange system comprising:

a top surface ( 12 ) and a bottom surface ( 14 );

a peripheral wall ( 16 ) extending between said surfaces ( 12 , 14 ) and about a periphery of said surfaces ( 12 , 14 ) with said peripheral wall ( 16 ) defining a cylindrical blower compartment ( 18 ), an evaporator compartment ( 20 ), and a diffuser ( 22 ) extending between said compartments ( 18 , 20 ) for facilitating air flow from said blower compartment ( 18 ) to said evaporator compartment ( 20 );

said diffuser ( 22 ) defining an entry area in a cutoff plane ( 30 ) at an entry to said diffuser ( 22 ) from said cylindrical blower compartment ( 18 ) with said cutoff plane ( 30 ) being transverse to said diffuser ( 22 ) and an exit ( 28 ) for establishing a direction of air flow into said evaporator compartment ( 20 ), and said peripheral wall ( 16 ) further extending from said exit ( 28 ) to define a vane wall ( 38 ) of said evaporator compartment ( 20 );

said vane wall ( 38 ) curving inwardly from said exit ( 28 ) of said diffuser ( 22 ) into said evaporator compartment ( 20 ) for redirecting air flow exiting said diffuser ( 22 );

a plurality of parallel vanes ( 46 , 48 , 50 , 52 ) disposed in spaced relationship along and substantially transverse to the direction of said vane wall ( 38 ) with said plurality of vanes ( 46 , 48 , 50 , 52 ) including a first vane ( 46 ) proximal said diffuser ( 22 ) and a second vane ( 48 ) spaced from said first vane ( 46 ) on the opposite side thereof downstream from said exit ( 28 ) of said diffuser ( 22 ) for redirecting the airflow across said evaporator compartment ( 20 ); and

said first vane being positioned from said cutoff plane ( 30 ) at a distance (L 1 ) of not greater than 1.9 times the square root of said entry area divided by the value of pi.

2. A casing as set forth in claim 1 wherein said first vane ( 46 ) has a height (H 1 ) of not greater than six percent of the square root of said entry area divided by the value of pi.

3. A casing as set forth in claim 2 wherein said peripheral wall ( 16 ) defines an outer wall ( 24 ) and an inner wall ( 26 ) of said diffuser ( 22 ).

4. A casing as set forth in claim 3 further including a first side wall ( 34 ) of said evaporator compartment ( 20 ) defined by a portion of said peripheral wall ( 16 ) extending transversely to said inner wall ( 26 ) of said diffuser ( 22 ) and including a second side wall ( 36 ) of said evaporator compartment ( 20 ) defined by a portion of said peripheral wall ( 16 ) extending transversely to outer wall ( 24 ) of said diffuser ( 22 ) and spaced from said first side wall ( 34 ).

5. A casing as set forth in claim 4 wherein said peripheral wall ( 16 ) and said top surface ( 12 ) define a vent therebetween, opposite said vane wall ( 38 ) and between said first ( 34 ) and said second ( 36 ) side walls, said vent is divided by a support ( 72 ) extending between said first ( 34 ) and said second ( 36 ) side walls to define a first vent ( 42 ) and a second vent ( 44 ).

6. A casing as set forth in claim 5 wherein said top surface ( 12 ) of said evaporator compartment ( 20 ) defines a concave portion ( 76 ) extending between said first ( 34 ) and said second ( 36 ) side walls and a radial baffle ( 74 ) extending between said first ( 34 ) and said second ( 36 ) side walls and disposed between said first vent ( 42 ) and said concave portion ( 76 ) of said top surface ( 12 ).

7. A casing as set forth in claim 6 including a door ( 80 ) rotatably hinged adjacent said support ( 72 ) and extending between said first ( 34 ) and said second ( 36 ) side walls, said radial baffle ( 74 ) defining a curved side ( 82 ) adjacent said first vent ( 42 ) complementary to a curved path mapped by said door ( 80 ) as said door ( 80 ) rotates.

8. A casing as set forth in claim 7 further including a heater flange ( 84 ) extending from said bottom surface ( 14 ) of said evaporator compartment ( 20 ) between said first ( 34 ) and said second ( 36 ) side walls, said heater flange ( 84 ) defining a top edge ( 86 ) for communicating with said door ( 80 ) such that said airflow flows exclusively through said first vent ( 42 ) when said door ( 80 ) is in contact with said heater flange ( 84 ), said door ( 80 ) controlling airflow by rotating between said vent flange ( 74 ) and said heater flange ( 84 ).

9. A casing as set forth in claim 8 further including a heater ( 90 ) situated between said support ( 72 ) and said bottom surface ( 14 ) of said evaporator compartment ( 20 ) and spanning between said first ( 34 ) and said second ( 36 ) side walls such that air passing through said heater ( 90 ) exits said casing ( 10 ) through said second vent ( 44 ).

10. A casing as set forth in claim 1 wherein said casing ( 10 ) is comprised of a top piece ( 92 ) and a bottom piece ( 94 ).

11. A casing as set forth in claim 10 wherein said vanes ( 46 , 48 , 50 , 52 ) are disposed on only one of said top ( 92 ) and bottom ( 94 ) pieces of said casing ( 10 ).

12. A casing as set forth in claim 10 wherein said vanes ( 46 , 48 , 50 , 52 ) are disposed on both of said top ( 92 ) and bottom ( 94 ) pieces of said casing ( 10 ).

13. A casing as set forth in claim 10 wherein said top piece ( 92 ) includes an upper portion ( 96 ) of said peripheral wall ( 16 ) surrounding said top surface ( 12 ) and extending downwardly toward said bottom piece ( 94 ).

14. A casing as set forth in claim 13 wherein said bottom piece ( 94 ) includes a lower portion ( 98 ) of said peripheral wall ( 16 ) complementary to said upper portion ( 96 ) of said peripheral wall ( 16 ) of said top piece ( 92 ).

15. A casing as set forth in claim 14 further including a plurality of complementary tabs ( 100 ) disposed along the periphery of both the upper ( 96 ) and lower ( 98 ) portions of said peripheral wall ( 16 ) for securing said top piece ( 92 ) to said bottom piece ( 94 ).