[Christ]

My father, instead of insulating the attic, insulated the attic's floor with R60 worth of insulation, then topped it w/ a rubber/foil "blanket".

The sun on the roof keeps it warm enough up there in the winter to go up and mess with something for awhile, but the house doesn't lose nearly as much heat, and it's less area to heat up before the rest of the house gets heated.

Living in trailer parks, more recently, I've come across people who get things free all the time from those who don't know what they are...

One of my friends came across a "Carrier" central air unit, in working condition... it was one of the original units, that used a box with a radiator coil in it.. (kind of like the radiator in a car, water to air unit).

He was interested in finding a way to use it to heat/cool his home, without actually using it the way the manufacturer intended (park officials said no to putting concrete in the yard to mount the unit on.

We ended up putting a fan behind it, and running cold water through it. It was more than enough to cool the house, so we put a thermostat on the fan and the water valve. (Water is free in the park, it has a self-recycled water system.) Later he was interested in getting heat the same way, so we changed the position of it to replace the oil furnace he no longer wanted to use, and made the radiator blow into the duct work of the home. By adding hot water to it, (electric to heat the water from a "heat as required" water system) with a thermostat, again, to control the fan and the water flow, it was more than enough to heat the 30X72 modular.

This was one of the most interesting things I've ever done with garbage.

OP- I look forward to seeing more results on the heat pump idea... I'm contemplating an in-ground water circulation pump for my house when I build it.