Worth investigating ASHP for extension?

[Tin Soldier]

HI there,

 

I have an extension planned for march next year.

 

130m2 sips constructed, vaulted ceiling, single storey. circa 160-170mm kingspan ceiling and wall insulation, 100mm insulation under the slab. I realise this is nowhere near the standards most on here insulated to, but it is what it is.

 

UFH throughout the extension, circa 30m2 triple glazed windows.

The existing property is insulated (not to any great level) oil fired combi boiler. no thermal store/cylinder.

 

I'm exploring ideas around heating as efficiently as I can

 

does anyone see any value in investigating a self installed ASHP to heat the ufh of the extension?

We're in a pretty cold/windy part of Scotland, so not sure if it would cope

 

any thoughts?

 

 

[ProDave]

Try and get more insulation under the UFH otherwise some of your heat just heats up the ground under your extension.

 

Do you need a SAP assesment for an extension? if so that should tell you the heating demand. Without that it's hard so size a system.  That's a big extension, bigger than some people's entire house.

 

I am going to be using an air source heat pump, probably a colder but less windy location to you.  Search around for a bargain and you will buy the heat pump quite cheap, then it's just plumbing and some wiring.  If it's only running the low temperature UFH then it should work very well.  I would suggest fitting a buffer tank to avoid the heat pump short cycling.

[Tin Soldier]

no sap assessment required, I believe its based on ration of floorspace to glazing, could be wrong.

 

I am toying with the idea of increasing the 100mm insulation, especially if I can get a good price on insulation - the 100mm was put in for building warrant etc.

any recommendations on thickness?

 

happy to install buffer tanks etc to assist,

 

Just wondering is ASHP could be a goer

 

[MikeSharp01]

Given other experience here I would say yes, getting the control system right is  bit of challenge but the basic idea, running at a great COP (Coefficient Of Performance) , makes sense and will probably pay for itself, in saved oil costs, in a reasonable period.