Electric Heatpumps.

For most folk with £ 5k to spare, looking very hard at reducing the heat lost from the building will be a more useful exercise. ‘negawatts’ - power off the bill are a true saving.

 Round here there has been a spate of solid wall  ex council houses developing 100mm of celotex style insulation and then an outer brick skin - making it into a thick-fill cavity wall with the old wall as a rather heavy inner leaf. Apart from  drilling to screw in wall ties and really deep window cills with creative brickwork shapes near doors that open out and so on,  the disruption to the folk living indoors while the work is being done seems to be pretty minimal, compared to taking all the floors up to plumb in a new heating system.

I only know one person who had it done well enough to ask them , but the result is apparently ‘toasty warm’, and if my estimating likely U values of perhaps 2 watts/degree.m2 for the old wall and maybe 15% of that afterwards are anything like it, I can well believe that. 

 I suspect that sort of investment to be a better bet and to be delivering savings long after any heat-pumps being  installed right now have reached end of life.

Mike

For most folk with £ 5k to spare, looking very hard at reducing the heat lost from the building will be a more useful exercise. ‘negawatts’ - power off the bill are a true saving.

 Round here there has been a spate of solid wall  ex council houses developing 100mm of celotex style insulation and then an outer brick skin - making it into a thick-fill cavity wall with the old wall as a rather heavy inner leaf. Apart from  drilling to screw in wall ties and really deep window cills with creative brickwork shapes near doors that open out and so on,  the disruption to the folk living indoors while the work is being done seems to be pretty minimal, compared to taking all the floors up to plumb in a new heating system.

I only know one person who had it done well enough to ask them , but the result is apparently ‘toasty warm’, and if my estimating likely U values of perhaps 2 watts/degree.m2 for the old wall and maybe 15% of that afterwards are anything like it, I can well believe that. 

 I suspect that sort of investment to be a better bet and to be delivering savings long after any heat-pumps being  installed right now have reached end of life.

Mike