> Does anyone attempt to recover waste heat from a ... engine used on a ve= hicle ? You've already mentioned one prominent instance - Turbosupercharging. A pet scheme of mine is a refrigeration unit run by waste heat. Someone's already done it & I don't know about it, probably. Jack --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .