Does anyone install indoor Air Source Heat Pumps (to heat central heating water & hot water tank) indoors? Most of the units I can find are external and I've nowhere to put one - mostly because I've no back garden and they tend not to be pretty and as I'm in a quiet rural kind of terrace, any perceptible noise at a couple of meters wouldn't be tolerated. Putting one in the loft with the hot water tank etc, would solve the visual issues and would surely allow for sound proofing. Obviousl