Barn conversion heating options

Tarbh

As per the title, we are about to commence on a barn conversion project in the Scottish highlands, and I'm looking into my options for heating and domestic hot water.

The barn will be stripped back to bare walls, so will have will have the latest spec insulation board installed (Kingspan etc), and we plan to use it as a holiday let, so it'll be primarily used from April until September.

Our own house has oil heating (no mains gas available) , so there is an option to use our oil tank to supply an oil combi boiler and radiators.

I've also thought about Solar thermal for DHW, and electric heaters, given that it's going to be so well insulated and mostly used in the warmer months.

Or potentially all electric with modern storage heaters.

The electrical supply to the barn is currently fed from our own house, but there is an option to get a separate supply run into the barn if required (Obviously at additional cost), but then we could take advantage of Economy 7 tariff for modern storage heaters.

My budget for this part of the project is not unlimited, so I don't want to go down the ASHP route unless I'm pushed to by building control.

Any thoughts on which way i should go.

Thanks...

lohr500

If it was me, I would go with an oil boiler for now, fed from your existing tank. (Assuming the tank is big enough to support both properties without needing to be filled up every few weeks).

I think the running costs for oil will work out cheaper than Economy 7/storage heaters/electric water heating.
Particularly in a holiday let, where clients may want lots of hot water during peak electricity time after returning from a day exploring the Highlands.

I would however look to future proof the installation to make it ASHP friendly in the future. So larger radiators to allow for a lower water flow temperature and possibly wet underfloor heating in the areas where you are putting new floors down. Doing this during the initial fit out will be a lot less costly than having to retro fit later.

QrizB

Welcome to the forum.

Insulation. Lots of insulation. More than you think you need.

For a summer-only holiday let, a multisplit air-air heat pump could cost less than storage heaters (plus will offer aircon as a bonus to your clients). @danrv has recently fitted one to replace his storage heaters; he has a thread about it here.

BUFF

Depending upon how old/type of construction you should check whether your insulation needs to be/is breathable to avoid potential issues with interstitial condensation. Historic Environment Scotland & their offshoot The Engine Shed https://www.engineshed.scot have a lot of info/advice available for updating traditional buildings.

If you do go down the oil combi route I agree about futureproofing for heat pumps by designing the system to run at low flow temps - it will also help your condensing combi run at it's most efficient now. Plus get controls that allow for load & weather compensation.

markin

Are winter holidays not just as in demand as summer or demand a premium? Or would the heating wipe out all the profit, not using it in winter will be wasting an asset that could be making income.

Tarbh

Thanks for the feedback, and the points raised about future proofing with regards to the ASHP.
I need to get some quotes now!

Tarbh

markin said:

Are winter holidays not just as in demand as summer or demand a premium? Or would the heating wipe out all the profit, not using it in winter will be wasting an asset that could be making income.

There is more demand in the summer, but once we get it up and running...we will probably have it available to let all year round.

billy2shots

I'm in the very early stages of looking to do a conversation from my steel frame barn. Need another year to go for the Permitted development Q route..

Lightly looked at heating I have no gas but mains electricity. 

Why have air source heat pumps been mentioned several times but not ground source?
Presumably ground source is more expensive? 

From a tiny amount of research, gshp with underfloor heating seems the go to method.

QrizB

billy2shots said:

Why have air source heat pumps been mentioned several times but not ground source?
Presumably ground source is more expensive?

I think the challenge is that ground source is something like twice the price to install but only slightly cheaper to run.

Reed_Richards

QrizB said:

I think the challenge is that ground source is something like twice the price to install but only slightly cheaper to run.

For ground source you either need a spare paddock where you can bury the heat "receivers" in shallow trenches - or you could use a lake if you have one.  Failing those you need boreholes, possibly more than one, which turn out to be hugely expensive to drill.  That's why the price of the installation is so high.

Underfloor heating is good because it requires a lower water temperature and that means you can run your heat pump more efficiently so your running cost are lower.  However a heat pump and suitably sized radiators is a perfectly viable option.     

Flight3287462

OP if the house was your own main dwelling then I would advise GSHP assuming you have a bot of land for the array.  GSHP is the best COP you can get.

Second would be ASHP and would be suitable for this.

To me storage heaters are a bit last century and with the rumour of economy 7 being phased out may not be a good idea.

Anything using oil has potential to get very expensive going forward.

So for me a decent log burner (people like a fire and on holiday probably even more so) and ASH would be my thoughts.