Heat Pump Questions

Telegraph_Sam

I don't know / am trying to find out if this is THE thread for heat pump correspondence. And if it is the place to look for BASIC advice on the pros and cons and economics of switching to heat pumps for my energy needs. I get the impression that most of the correspondence in this thread is rather "advanced" and that the contributors know what they are talking about, in contrast to myself.
At present I must count myself lucky for being on favourable fixed tariffs for both gas and electricity. Whilst my gas combi rates as "old", the advice I have received is that it would be madness to change at this point in time. [If it ain't broke ..] I would like to explore the economics for myself but how and where to get informed and unbiased advice? I don't run an EV  and my consumption is moderate.

QrizB

Telegraph_Sam said:

I don't know / am trying to find out if this is THE thread for heat pump correspondence. And if it is the place to look for BASIC advice on the pros and cons and economics of switching to heat pumps for my energy needs.

Most heat pump chat is in the "other fuels" forum:

https://forums.moneysavingexpert.com/categories/lpg-heating-oil-solid-other-fuels

Some is in "green & ethical":
https://forums.moneysavingexpert.com/categories/green-ethical-moneysaving

The main "energy" forum, where you are now, is definitely third ranked in that list.

Verdigris

Telegraph_Sam said:

I don't know / am trying to find out if this is THE thread for heat pump correspondence. And if it is the place to look for BASIC advice on the pros and cons and economics of switching to heat pumps for my energy needs. I get the impression that most of the correspondence in this thread is rather "advanced" and that the contributors know what they are talking about, in contrast to myself.
At present I must count myself lucky for being on favourable fixed tariffs for both gas and electricity. Whilst my gas combi rates as "old", the advice I have received is that it would be madness to change at this point in time. [If it ain't broke ..] I would like to explore the economics for myself but how and where to get informed and unbiased advice? I don't run an EV  and my consumption is moderate.

Heat Pumps for the Home, by John Cantor is an excellent primer. Written at various levels to suit almost any level of scientific competency.

Telegraph_Sam

QrizB said:

Most heat pump chat is in the "other fuels" forum:

https://forums.moneysavingexpert.com/categories/lpg-heating-oil-solid-other-fuels

Some is in "green & ethical":
https://forums.moneysavingexpert.com/categories/green-ethical-moneysaving

The main "energy" forum, where you are now, is definitely third ranked in that list.

Thanks. Within the first there would seem to be quite a number of sub-forums or more correctly threads to choose from.

Reed_Richards

Telegraph_Sam said:
Thanks. Within the first there would seem to be quite a number of sub-forums or more correctly threads to choose from.

With a heat pump, properly installed, you might use about 1/3 of the energy you would otherwise use to heat your house.  So if you just care about the economics then in your case a heat pump will only become economically viable on running costs when the price of gas per kWh is more than 1/3 of the cost of electricity per kWh.  That is not the situation now and will not happen soon unless the government increases taxes on gas. 

Telegraph_Sam

That is a useful rule of thumb / yardstick.  My gas costs me 3.05 p/kWh. The average of my peak and off-peak electricity tariffs works out at 10.58 p/kWh (in both cases excl VAT). So at current rates there is not a lot in it, considering that actual gas usage must be less efficient than electricity.  On the other hand one would have to bring to the equation everything that would come within the term "conversion costs" which would need to be amortized by any savings. Gut feeling makes me think that on my consumption reaching break even could take a long time.

brewerdave

Reed_Richards said:

Telegraph_Sam said:
Thanks. Within the first there would seem to be quite a number of sub-forums or more correctly threads to choose from.

With a heat pump, properly installed, you might use about 1/3 of the energy you would otherwise use to heat your house.  So if you just care about the economics then in your case a heat pump will only become economically viable on running costs when the price of gas per kWh is more than 1/3 of the cost of electricity per kWh.  That is not the situation now and will not happen soon unless the government increases taxes on gas. 

@Telegraph_Sam -also remember that a heat pump circulates water at lower temps. so it is essential that you minimise all heat losses from your dwelling which can mean uprating insulation ,windows, doors etc - can mean a lot more costs than "just" a heat pump and new radiators.

Telegraph_Sam

Yes I'd  heard  that argument before even if I don't fully understand the mechanics. Reinforces the arguments in favour of sitting tight.

Reed_Richards

brewerdave said:
@Telegraph_Sam -also remember that a heat pump circulates water at lower temps. so it is essential that you minimise all heat losses from your dwelling which can mean uprating insulation ,windows, doors etc - can mean a lot more costs than "just" a heat pump and new radiators.

This is oft repeated but it is not actually true, there is no connection between heating water temperature and the need for insulation; why should there be?  Yes, you will need new radiators and if you want a government subsidy you need an EPC that does not recommend additional loft or cavity wall insulation.  But that is a rare instance of the government being sensible and not wanting to subsidise the heating for a house that could be better insulated.  The thing that is really important is that you have radiators that will give you the heat output you need at the lower water temperature.  If the output capacity of the radiators is too small then you'll never get the house warm enough in cold weather and you'll force the heat pump to work too hard so it's not as economical as it should be..      

Telegraph_Sam

This was one of the aspects that puzzled me. If the house is too cold you turn up the heating. But the  implication seems to be that the heat pump has an optimum (lower) heat setting and if that is too low then they lose their efficiency.  How getting different radiators compensates for this comes over at first sight as snake oil. If there is only a set amount of heat generated in the first place how can different radiators magically increase this? And what about taking showers in winter? Or having water sufficiently hot for washing up?  Despite my cynicism I am prepared to believe that there is an answer to these anomalies