Completely new to heat pumps

minnemouse25

Hi everyone

I am completely new to all of this - but we are looking to purchase a property that already has central heating via an air source heat pump. I know absolutely nothing about how this sort of system works and how it could compare in cost to what we have now.

Currently we have multi fuel heating, with all of our heating and hot water coming from a multi fuel stove with back boiler. We run it on a mixture of anthracite and wood - the anthracite costs us about £150 per month, and we buy firewood from the forestry commission at around £200 for one year supply. Our cooking is via free standing gas bottles - with one bottle lasting around 12 months at a cost of £100. Our hot water is either heated from the stove or from an electric immersion heater.

Our electricity bills are around £160 per month (we have a hot tub which we would like to take with us which means our electric is a bit higher than you would expect, but also we are a family of 4 with hundreds of devices plugged in and charging all the time, plus I work from home so have a laptop, and various other things plugged in being used constantly)

My concern (other than not having a clue what an air source heat pump actually is), is whether this could work out to be a lot more costly to run. As I work from home, I need the house to be warm during the day. One of the reasons we are looking to move is to reduce our mortgage costs, but I don't want a situation where any money we save on the mortgage is then wiped out by the additional costs of running this heating system - in which case I would rather stay where we are!

The pump itself is an Eco-dan Air Source Heat Pump and according to the home report is "newly installed". The radiators are absolutely massive in the house - I have never seen anything like these before, but they are all new, as is the pipework. It is a house dating back to the 1900s so I don't know how well insulated it is.

Any thoughts would be most welcome, thank you in advance!

subjecttocontract

The vendors are legally required to provide an Energy Performance Certificate (an EPC). Ask to see it, it should answer many of the questions you have on insulation/ performance.

Ask also to see receipts/ guarantees for insulation/ building works associated with the heat pump installation.

Reed_Richards

For all we know you could be moving from a mansion to a shack, so it's impossible to say how your new heating costs will compare to what you pay at present.  For rough guidance, a heat pump should cost much the same as a gas boiler to run.  If you are looking to economise, leave that hot tub behind when you move.

minnemouse25

Looking at the EPC, estimated costs are the same as what we pay now. Sqm is roughly the same, the reduction in mortgage comes from the fact we are moving from an extremely overpriced, expensive area to one that is not. We are in a new build now, and the house we are interested in doesn't appear to be insulated according to the home report - recommendations were made for this.

I am also a little concerned about reports that this form of heating is not particularly effective?

Netexporter

If it is a new-build the insulation should be to the current Building Regulation standards.

As for running the system, remember the mantra "low and slow" and you won't go too far wrong. The reason the radiators are so large is because heat pumps work most efficiently at lower flow temperatures, therefor you need larger emitters to provide the same rate of heat transfer. You will need the heating to come on earlier than for a "traditional" boiler. It is also good practice to limit the difference in day to night-time temperatures to about 3 degrees. Effectively, this means the heat pump will be running almost continuously, but at a "tick-over", where it will achieve the higher COP (coefficient of performance), so for every kWh of electricity consumed you may get 4 kWh of useful heat.

Netexporter

Oh, and You and Yours (Radio 4) is discussing heat pumps today, which may (or may not) be useful. 

minnemouse25

Thanks Netexporter - but it is our current house that is the new build, the house we are looking at moving to dates from the early 1940s but doesn't appear to have any insulation, hence my concern

Netexporter

Sorry, speed-reading!

There is no reason why the heat pump will not be adequate, provided the system has been correctly designed. It costs a lot to heat a poorly insulated home whatever fuel you use.

You will probably find that you will use a lot of electricity at the start of the heating season as the fabric of the building "fills up" with heat. Once it has reached equilibrium, then the energy demand will reduce. Again, the low and slow approach is you friend.

Obviously, any draught-proofing or other heat conservation measures you can apply will help to keep costs down but, again, that applies to all houses.

Gerry1

Ask to see all the energy bills since the heat pump was installed.  You may find it's the reason they're moving out ! 🫢

matt_drummer

Gerry1 said:

Ask to see all the energy bills since the heat pump was installed.  You may find it's the reason they're moving out ! 🫢

`Always with the negative waves Moriarty'

MultiFuelBurner

minnemouse25 said:

Looking at the EPC, estimated costs are the same as what we pay now. Sqm is roughly the same, the reduction in mortgage comes from the fact we are moving from an extremely overpriced, expensive area to one that is not. We are in a new build now, and the house we are interested in doesn't appear to be insulated according to the home report - recommendations were made for this.

I am also a little concerned about reports that this form of heating is not particularly effective?

It's a learning curve for sure it's not like you can fire up the heat pump to max temp and not expect it to cost a fortune as they work at lower flow temps.

The good news is with you working from home you can go low and slow 24/7 and with a smart meter open up very cheap tariffs for your electricity.

The people we bought our house off had been running the heat pump since the house was new. They didn't do much research and burned approx 9000kwh a year and they were working from home like we do.

Our current consumption is 6250kwh a year and it's 21oC or higher in every room over winter.

There is a lot of misinformation about heat pumps like there is with smart meters. Hence the people that pop up on smart meter and heat pump threads from time to time with their one liners, you just have to ignore them and eventually they will get the message.