Heat Pump question

uk1

Hi all,

In considering a heat pump is a viable option to retain an existing oil fired system and keep existing radiators and pipework and simply have the heat pump work in tandem?  I currently use logs and oil and wouldn’t want to change from this but simply see the heat pump as an add on.

Thanks. 

Coastalwatch

Hi @uk1 by adopting an Air2Air heat pump(Air coniditioning unit) you can do precisely as you suggest as it is totally independent of the systems you have in place and well worth implementing in my experience. Unfortunately this isn't the same with an Air to Water heat pump which would need to replace that already in place and at higher cost.

uk1

Thanks for your time.

So …. air to water couldn’t use my existing radiator and pipes alongside my oil boiler? 

Martyn1981

uk1 said:

Thanks for your time.

So …. air to water couldn’t use my existing radiator and pipes alongside my oil boiler? 

It might, but if you are simply looking for an add on, as you say, then it would be simpler and cheaper to add a couple of A2A units (air con units).

Coastalwatch did that and was able to remove the GCH. I've done a smaller version, and cut gas consumption, with some of the leccy coming from PV.

I also assume that a full ASHP install will not attract any subsidy if you are colocating with the oil boiler, so that adds £5k to the price.

shinytop

uk1 said:

Thanks for your time.

So …. air to water couldn’t use my existing radiator and pipes alongside my oil boiler? 

uk1 said:

Hi all,

In considering a heat pump is a viable option to retain an existing oil fired system and keep existing radiators and pipework and simply have the heat pump work in tandem?  I currently use logs and oil and wouldn’t want to change from this but simply see the heat pump as an add on.

Thanks. 

In theory, yes.  A hybrid system uses fossil fuel and a heat pump. When it's relatively mild (say 5 degrees and above) the ASHP does the work.  When it's colder the ASHP stops and the ff boiler takes over.  Google 'hybrid heat pumps' for lots more info.  BTW they don't work in tandem; it's one or the other at a time but the switching is automatic.

One issue might be if your radiators are sized for an oil system heating the rads to 70 degrees, they might not heat your house at optimum ASHP flows, say 40 degrees.  And if you're going to change all your radiators, some would say you may as well go full ASHP plus logs and ditch the oil.    

Reed_Richards

I think my ASHP has controls that allow it to be integrated with a second heat source like an oil boiler and you can certainly buy hybrid systems; Grant tried to sell me one when I was first looking at heat pumps.  But if you keep your existing radiators then you'll end up using the heat pump only when it's mild outside so you only need a fraction of the normal radiator output.  That's probably not worthwhile, particularly at the moment when oil is relatively cheap compared to other forms of heating.

Unless your existing radiators are an integral part of your décor, it's a mistake to think you want to keep them.  You may well be able to replace them with radiators with more internal fins to achieve a higher output without the new radiators needing to take up more wall space.   

uk1

Thanks for all the feedback.  Not for me and the feedback and advice was extremely helpful. 

mrmmhf

We have hybrid oil boiler system working alongside our air source heat pump. We discuss how we set it up here and that should answer some of the questions you have:

https://youtu.be/yP-hsA5nmy8

The big decision is choosing a heat pump that’ll happily work alongside your boiler.

PaulbytheRidgeway

uk1 said:

Hi all,

In considering a heat pump is a viable option to retain an existing oil fired system and keep existing radiators and pipework and simply have the heat pump work in tandem?  I currently use logs and oil and wouldn’t want to change from this but simply see the heat pump as an add on.

Thanks. 

Hi. We are the same with oil burner and logs.  Good news is log burner can stay! But if you want to benefit from the £7,500 Boiler Upgrade Scheme then your oil fired boiler has to be removed (by installer, not an ebay buyer) as its a condition of getting the support.   We have just had a quote from Good Energy for 4 bed bungalow and it includes new rads in all rooms, as they are too small for the lower temp heating (c50 degrees) and full of crud (incl under-house double garage) and option of using existing recent cylinder or a new heat pump one (+£2k difference).    With the BUS we are looking at £9,200 and without it it would be almost £17k.   So, not cheap by any means and there's a bit of thinking to do.  If we do go ahead I can't see us doing this without the BUS.   Like choices about electric cars and solar PV (we have both), it isn't about saving money as all this costs ££s but does combine lower maintenance and running costs with some reduction in CO2 footprint. I don't know how running costs stack up - but we can't escape when oil/diesel and electricity all head skywards :-(

QrizB

PaulbytheRidgeway said:

We have just had a quote from Good Energy for 4 bed bungalow and it includes new rads in all rooms, as they are too small for the lower temp heating (c50 degrees) and full of crud (incl under-house double garage) and option of using existing recent cylinder or a new heat pump one (+£2k difference).    With the BUS we are looking at £9,200 and without it it would be almost £17k.

Have you had a comparison quote from Octopus? They've been giving good prices (I declined, not ready to switch from gas yet).

https://octopus.energy/get-a-heat-pump/

An occasional forum poster, Matt Drummer had an Octopus install. He was very happy with the workmanship but had some reservations over the specification (he thinks they've fitted an oversized heat pump).

Reed_Richards

I have not been following oil prices closely but last time I looked, a reasonably efficient oil boiler would be cheaper to run that a heat pump.  Or cheaper than a gas boiler on the SVT, for that matter.