HampshireHedgehog

Sadly this will never be a very low energy house, so the linked options are interesting examples of what can be done but wouldn't work for me. Since the oil boiler died, we're currently "heating" it by moving 2 x 2KW fan heaters and a 1.5KW electric radiator about and it takes a few hours in the morning for them to raise the temperature to tolerable. There's plenty of insulation work that can be done: secondary glazing, loft insulation (currently just plaster and lath ceilings with a fully boarded loft above) but there's a limit to what's practical in a Victorian house. (~10mx10m footprint - ground floor 4m ceilings - upstairs 3.5 m high, South aspect has single glazed sash windows, North is sheltered and double glazed, neighbours houses attached to east and west. At least the walls are thick and we've thick curtains)

Thanks - I guess a duct bigger than a dustbin might raise some eyebrows and fail to get aesthetic approval from the other freeholders - I could hide it on one side of the roof but to separate them you'd probably want one vent each side. Sounds like oil is my option then until a GSHP gets less expensive.

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. Obviously I'd need to duct the incoming and outgoing air with large diameter pipes. We can't get gas and I don't want another oil boiler, I think bore hole ground source is likely to be too expensive. Googling for "Indoor air-to-water heat pumps" and "Internal Air Source Heat Pump" I can only find a discontinued commercial unit requiring 3 phase and a German system that seems not to be sold anywhere. Does no-one sell proper built in heat pumps? Is the issue that people tend to either have gas or enough space to hide an external unit? Another forum expressed the concern that if the ducts were smaller than the external unit's fans then you'd need a higher air speed which might be noisier but I've seen things suggesting a centrifugal fan can be quieter than an axial (proppeter type) fan, and don't mind big ducts. There was also concern about the loft getting hot - but ours is an aircraft hangar sized loft and could easily be vented.