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What combination of technologies to install?

greencardiff | Posted in General Questions on

EDIT: I’m from the UK and have just realised this is a US forum. I realise advice, terminology, technologies and prices may vary from country to country! Still, any thoughts welcome. 

We’re planning a move into a fairly standard 1950s, 4-bedroom semi-detached house, and thinking about how we might improve its energy efficiency straight away. It currently has double glazing (recent) and modern radiators, plus a fairly old looking combi boiler. I’m not yet sure about the insulation situation – there is a loft extension which looks recent so probably has a decent amount of insulation in the ceiling, but I don’t know if there is cavity wall insulation.

We’re prepared to spend up to around £20k to go beyond the normal measures, and I’m looking at the following:

– New more efficient combi boiler, possibly combined with solar thermal water heating

– Electric car charging port (type 2) – to charge our existing car

– Solar PV, with an installation that would allow car charging with ‘spare’ electricity, while feeding into the grid when the car is charged

– Air source heat pump (but the house has brand new, expensive looking radiators and I don’t fancy replacing them with new ones – I understand heat pumps work best with either underfloor heating or larger than conventional wall radiators)

The house’s back roof is south facing.

Any advice/thoughts on what we might plan doing would be much appreciated. We’d be getting professional installation, so that would be a factor in all cost considerations.

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  1. walta100 | | #1

    The first thing is to keep the conditioned air inside your house by fixing the hundreds of leaks. It is most important to fix the highest and lowest leak first as the pressure differential will make more air flow at the top and bottom.

    See if you can find someone with a “blower door” to test your home find and fix the leaks and test again so they can measure the improvement.

    Then insulate the wall to slow the flow of heat thru them. None of what I am recommending is anything one can show off and brag about it is hard and dirty work that no one will notice.

    Replacing operational heating equipment almost never pays off from a financial point of view unless the fuel costs are 5 time lower for the new fuel. Most people in the US move on to a different house before the seventh year.

    Solar thermal water heating is all but dead in the US because PV solar has gotten inexpensive enough that it cost less to add PV and an electric water heater giving you better comfort with fewer points of failure.

    When I think of England blue skies and sun shine are noy my first thoughts. I have a hard time imagining how one could recover the cost of a PV install if it is as cloudy is I am thinking it is.

    When your current heating system had failed to the point replacement would be required consider an air-to-air heat pump. The air to water heat pumps has greater losses because they must make the water 20° hotter than the air they are trying to warm.


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