[mort]

Originally Posted by Big time

Pretty much like propane gas refrigerators
Only using exhaust heat instead of propane gas as the heat source?

HowStuffWorks "Gas and Propane Refrigerators"
Absorption refrigerator - Wikipedia, the free encyclopedia

People want to be be cool even at idle. The A/C will need a few hp to work, but at idle there isn't that much heat available.
-mort