Storing engine heat

[JohnAh]

A rough calculation told me that even if I have a quite big house in Sweden where winters may be cold I still spend about two or three times more money on fuel for my car than heating the house. Knowing that my car wastes 2/3 of the fuel as heat feels rather annoying this time of the year.

My experiences from many years with under-motorized cars says that weight reduction is not always beneficial. The average travel time have not differed notably between the number of passengers for example. A high weight may even be better when driving through a landscape with many smaller hills and slopes. A higher weight may act as a flywheel smoothing out the speed once it has been reached.

So, how about installing at heat accumulator to store some of the lossy heat from the engine and use this "free" energy for household heating? I know there are some saline solutions that can store way more energy than plain water but they may be expensive? Plain water is cheap and not the slightest harmful to the enviroment. I don´t remember how I got the numbers but I once calculated that an ordinary oil barrel of 200 liters should be able to store the heat generated from some 10´s of kilometers of driving.

[chrisgerman1983]

You could run your exhaust through a block of cement? and run a duct through the same block. when you get home you could hook up the duct to your house and blow the heat stored in the thermal mass into your house? Or the exhaust could run through a tank of water that you could pump into a radiant heat system?

[Ryland]

Tractor hydraulic quick connect hoses can handle large amounts of liquid without letting air in, people have used these common connections on trucks and tractors to move engine coolant in a ground loop or in an on demand hot water heater to preheat an engine, connecting it after the engine is warm would pull the heat out of the engine as well.
By "plugging" your car in to your house, you could preheat your engine, saving gas and when you return you could put that expensive heat back in to your house, where it will be enjoyed by you instead of slowly lost from your car.

[radioranger]

well on boats they water cool the exhaust and use a water to water exchanger instead of water to air like a car does., suppose all the present radiator flow went into a barrel and returned, then if you got too much heat an extra coolant loop with a small radiator could be switched on , or just use a water cooled exhaust only then if temps go too high vent the steam

[euromodder]

Originally Posted by radioranger

well on boats they water cool the exhaust and use a water to water exchanger instead of water to air like a car does.,

It's more efficient that way, and the water is available.

suppose all the present radiator flow went into a barrel and returned, then if you got too much heat an extra coolant loop with a small radiator could be switched on , or just use a water cooled exhaust only then if temps go too high vent the steam

You'd have to constantly drive around with all the extra equipment taking up volume and its weight - while serious weight reduction is key to high MPG.

By "plugging" your car in to your house, you could preheat your engine, saving gas and when you return you could put that expensive heat back in to your house, where it will be enjoyed by you instead of slowly lost from your car.

Not everyone lives in a home with an attached garage where they can hook up their car - one of the more serious issues with electric vehicles.

[radioranger]

All true , thinking out of the box here of course, none of this is very practical , except in extreme circumstances, wondered sometime though about a small steam turbine driven off wasted exhaust heat to make electricity

[arcosine]

Only 10 km to work, you could ride a bicycle.