Runaround loops, also known as coil energy recovery loops, use a coil placed in each air stream and connected by pipes filled with a heat transfer fluid, generally a glycol solution. A pump transfers heat from the exhaust air stream to the incoming ventilation air. This type of system is for sensible heat transfer only. Because the two air streams are separate units, there is no threat of exhaust contamination.
Hot water tank heated by wood burning stove. From Teach Nollaig, Tiny house in Ireland. Could be improved by adding a small sterling engine to power a circulation pump, allowing the hot water tank to be up higher [improving pressure]. Also INSULATION!
the woodstove. we did not have the oven option, but used our top surface to warm things. Yes, you had to think to 1 hour in advance but no microwave is a good thing. Now, no woodstove and we manage just fine. Want my woodstove back though