Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Why does the heater core transfer heat from the coolant, not the exhaust?

Bicycle Bob · 10-12-2008, 02:02 AM

[QUOTE=extragoode;66678]

Example: If you don't like toxic fumes and smells being transferred to the cabin along with the heat, use another medium as a buffer. Water/antifreeze responds to convection currents just like air does. Put heat exchanger from water mix to exhaust plumb to the coolant to air exchanger in the cabin. Bingo, best of both worlds! <snip>

Having a double - wall heat exchanger with fluid between them would bring a lot of the kind of safety we get with things like double-bottom tankers. However, the cost would go up a lot, and eventually, somebody would still let it fail.

There is plenty of heat conveniently available from the cooling system on most cars. When I see a motor so small that the rad is the same size as the heater core, I'll think about a valve to direct the coolant where it is needed. My metro warms up quite rapidly, because it works hard for its size.

The rule of thumb is that 25% of the heat in gasoline goes out the shaft, 25% out the rad, and 50% out the exhaust, so it is a rich source. I concur that it is most interesting as a way to feed an absorption cooler, or perhaps run the electrical generation.

10-12-2008, 02:02 AM	#15 (permalink)
Bicycle Bob EcoModding Apprentice Join Date: May 2008 Location: N. Saskatchewan, CA Posts: 1,805 Appliance White - '93 Geo Metro 4-Dr. Auto Last 3: 42.35 mpg (US) Stealth RV - '91 Chevy Sprint Base Thanks: 91 Thanked 460 Times in 328 Posts	[QUOTE=extragoode;66678] Example: If you don't like toxic fumes and smells being transferred to the cabin along with the heat, use another medium as a buffer. Water/antifreeze responds to convection currents just like air does. Put heat exchanger from water mix to exhaust plumb to the coolant to air exchanger in the cabin. Bingo, best of both worlds! <snip> Having a double - wall heat exchanger with fluid between them would bring a lot of the kind of safety we get with things like double-bottom tankers. However, the cost would go up a lot, and eventually, somebody would still let it fail. There is plenty of heat conveniently available from the cooling system on most cars. When I see a motor so small that the rad is the same size as the heater core, I'll think about a valve to direct the coolant where it is needed. My metro warms up quite rapidly, because it works hard for its size. The rule of thumb is that 25% of the heat in gasoline goes out the shaft, 25% out the rad, and 50% out the exhaust, so it is a rich source. I concur that it is most interesting as a way to feed an absorption cooler, or perhaps run the electrical generation. __________________ There is no excuse for a land vehicle to weigh more than its average payload.