Rough cost of air source heat pump plus radiators, plumbing, etc?

sw_mina

Dear all

We need a bit of advice on the ballpark cost of installing an air source heat pump into a detached house.

We are looking to buy a 3 bed 1930s dormer bungalow that has a scary EPC due to being on night storage heaters and an electric emersion for hot water. The energy costs per year are around £2000. So we're looking at what we can replace the night storage heaters with, given there is no mains gas an air source heat pump seems the obvious choice.

I've read that the units start at around £5000 but can't seem to get an idea on what it will cost to install it along with all the necessary radiators and plumbing. We have zero DIY skills to do much of the work ourselves...

I've also read that underfloor heating systems are more efficient but am guessing that is only realistic for new builds?

Thanks! I know it is a "newbie" type question but we are pretty new to this and need to factor in the costs in our offer for the house.

Smiley_Dan

While making change to your heating system sounds like an interesting project it might also be worth looking at reducing your energy loss.

What does your scary EPC say about insulation? Does draught proofing need doing?

By reducing your energy loss you benefit _whatever_ heating system you have, plus some heating systems that work with lower grade heat (heat pumps are an example) require relatively good levels of insulation to work efficiently (or at all).

While you are doing this work it's worth measuring how much you use and working how much much heat you really need. It's probably worth giving yourself a year or so of experience in the house. You don't want to make any expensive mistakes.

[Deleted User]

Hi,


We are also a detached bungalow from c1906.


LPG used to be the main heat source ~£200pm + electricity.


Now paying Eon £94pm, overpaying, for all heating/hot water/lighting etc after installation of an ASHP + 4kw solar pv.


We did insulate, draft proof etc but if claiming RHI you don't really have a choice as we were inspected twice that we had complied where possible...


TBH telling you what we paid will not help as each system will have to be tailored to your house and needs e.g. we spent over £4k on designer rads. I would suggest that you may need to double the £5k.


We also have a couple of new log burners which are great but in no way can they compete with the ASHP for running costs, convenience and speed of getting the house up to temp.


Cheers

sw_mina

Thanks for the advice.

As it's a dormer, I guess there is no possibility of loft insulation. The EPC says "roof rooms, ceiling insulated" - not sure if that means there is insulation between the ceiling and the roof or if the rooms are insulated by the ceiling itself!

The EPC recommends floor insulation. It doesn't mention draft proofing. The house is uPVC double glazed throughout and has cavity wall insulation already, so hopefully not too many drafts to be had, except perhaps through the floors.

The other thing the EPC recommends is new, fan assisted storage heaters (but I think we'd rather change completely if possible) and a dual immersion cylinder.

I think we want to sort out the heating before we move in, as there's a bit of decorating (and a new bathroom) needed and I'm guessing installing central heating is messy.

Oh, also, it's in Cornwall. We rarely get below zero here... hoping that means the lower temperature output will matter less than if it was somewhere cooler...

lovesgshp

You need to first of all get the thermal requirements of the house, as it is and then find what you need to improve them.
Underfloor heating will be fairly expensive to install, so if you decide to go the ASHP way, then look at fan coils for the rooms and compare the costs of those to UFH and the installation cost of each system.
Yes, a ASHP can cost a few thousand to much more. Get a good recommended unit and not a cheap Chinese import. In the UK the Ecodan seems to be the choice of many on here, so follow their advice.

Robwiz

Whilst it's tempting to get the heating installed before you move in I wouldn't do that. You need to know far more about the thermal properties of your bungalow and how you use the home.

From personal experience I wouldn't have much confidence in an installer getting the heat loss calculations right. With ASHP that's critical – undersizing leads to horrendous electricity bills and oversizing results in inefficient running.

My advice is to live with what you have for 12 months and work out how much your home costs to heat. The EPC figures can be very inaccurate. It's far better to understand how much heat you need to put into the bungalow through the year. For example, in March and April we haven't needed any heating at all on days when the outside temperature was only 12º or 13º because it has been sunny and solar gain has given us all the heat we needed and the insulation kept it in the house so that it was still warm the next morning. It's a different story when it's 11º and raining though so a few logs on the woodburner in the evening have been enough. Much cheaper than running the central heating.

I would also recommend you get a thermal scan when night time temperatures are low – that's the best way of identifying where you are losing heat from your home and enables you to identify where you will benefit from increased insulation.

An electric immersion heater shouldn't be costly provided it's on a timer switch that is set to be on for 30 minutes twice a day. I would be inclined to specify an ASHP that provided heating only with domestic water heating completely separate. All the horror stories I've read are about systems on which the ASHP water heating settings are wrong. It's better to keep things simple, and work on the basis that if it can go wrong then it will go wrong!

Smiley_Dan

Robwiz have you had a thermal imaging survey done? Any tips for that?

Robwiz

Yes I have. It's very worthwhile.

Look out for a local transition town group – they often run schemes for volunteers to be trained and scan their own homes. Also check with local authority for an officer responsible for carbon reduction or energy efficiency because they often run schemes. Where I live they have an Energy Champions scheme and one called Carbon Conversations.

I have seen independent consultants who charge around £200 for a thermal survey. I'd say mine would be well worth that for what we learned and have been able to fix. It shows up leaks around windows and doors, where CWI has been missed, thermal bridging.

Alycidon

Look at the Nottingham Energy Partnership website, they have an energy costs comparison site that also compares CO2 outputs.

A