We currently have a basic gas boiler providing domestic hot water but no central heating. We recently fitted new windows but the walls will remain badly insulated (30-40 mm of PU foam sprayed on external face of internal masonry leaf). However the winter is relatively short and warm here (with lows and highs of 6º to 15º Dec to Feb).

We're thinking to exchange the gas boiler for a hot water cylinder with integrated air source heat pump (e.g Dimplex Edel, Energie Aquapura Monobloc etc. that can vent directly through the external wall) and fit a few electric infrared or convection panel heaters. (there is EU funding available here up to €2500 to fit new heat pumps, solar thermal, PV etc.)

But if we're going to the trouble of fitting such a unit and we really want to lower our heating bills then would we be better to fit a heat pump that can also provide central heating?

Problem is I can't find hot water cylinders with integrated heat pumps that can provide this level of output.

We're on the first floor of a 4 storey block of flats and while it might be feasible to fit something on the roof I'd rather avoid that option if we can. First we'd need to get permission, then we need to find a route, it would need to be close enough, and then we'd need to be sure we're not create a noise nuisance for the top floor (the building performs very badly acoustically).

Are there any integrated units on the market that can provide central heating?

Posted By: ShevekProblem is I can't find hot water cylinders with integrated heat pumps that can provide this level of output

That may be your problem. There are integrated systems, but from what I've seen they seem to be targeted at highly insulated apartments with low heating requirements, ideally with underfloor central heating. As the heating demand goes up, the fan speed, airflow and noise all increase.

You may be better asking for permission to put one on the roof. Better still, see what grants & other support are available to install a communal system, which may work out cheaper and would benefit your neighbours too.