I've got an 11kw Daikin LT running in a 150sqm detached 3-bedroom bungalow with decent loft insulation, cavity wall insulation (of doubtful quality), double galzing ( installed in1999) and a suspended ventilated wooden floor with a polypie overlay u/f system on top, we should have had it insulated but we didn't. We live out in the Cambridgeshire Fens where its quite windy and very exposed.

I've got it set up to run with temp compensation so the average system temperature seems to be about 35dgrees, increasing to 42 when its down to 0 degrees or lower. We keep the hot water temp about 42 degrees (200l Daikin tank) and all of the bungalow is continuously heated to 17 degrees with uplift to 19-20 degrees in the mornings and evenings in the bathroom, bedroom and kitchen, the lounge and and middle bedroom are heated all day to 19-20 degrees. We are quite comfortable but do realise (after getting caught out the first year we had the system) that it takes a long time for the house temp to recover if it's turned down too low)

This is our third winter with the system. Last year our total electricity consumption was just over 8000kw (heating, hot water, lighting, washing, drying etc) We are noticing a higher consumption in this prolonged cold winter and gues it's going to be about 500kw higher this winter - In December & January this year we've used just under 3000kw which is 500kw higher than the same period last year - I read the meter every week so I know what's being used ( I cant separate the H/P consumption from the wholes house consumption).

As far as I'm concerened our power consumption is well within what I was expecting, significantly less than we would be paying with LPG or Oil, but my preference would stll be mains gas if it was available.