Air Source Heat Pump in barn conversion

hellogboy

Hello everybody ,
I have a 2 storey barn conversion totalling about 110 m2( 2 bed both en suite); going to put a Mitsu Ecodan with a 210litre kingspan cylinder and UFH on both levels; just hoping it is going to be warm enough bearing in mind i live in a cold windy northern place ( I also have an evoco 10 kw wind turbine in the pipeline but thats maybe for another thread on another day !!) I was initially attracted to the subsidy (RHI) being a farmer of course !!
It will be insulated well ( to current building regs) ; but just worried it wont have enough hot water /heat etc as it may be holiday cottage thanks:D

Cardew

Details of the RHI are due by the end of the year.

Will your barn qualify as a domestic property? Commercial properties are not included initially I understand.

hellogboy

Well it is an old granary on the farm that I have full residential planning for; so may be worth 'moving in ' at first;) The devil may be in the detail, but I will definitely look at that; thanks! Though it does seem a good alternative to Kerosene which is my only other option really

Mankysteve

I would over insulation don't just do it to current regs go over board you cant have too much insulation.

Look up passive house designs, heat exchangers ect to truly heat house for cheap best to reduce your heat leakage to absolute minimum.

Then you can worry about green heat sources.

zeupater

hellogboy wrote: »

Hello everybody ,
I have a 2 storey barn conversion totalling about 110 m2( 2 bed both en suite); going to put a Mitsu Ecodan with a 210litre kingspan cylinder and UFH on both levels; just hoping it is going to be warm enough bearing in mind i live in a cold windy northern place ( I also have an evoco 10 kw wind turbine in the pipeline but thats maybe for another thread on another day !!) I was initially attracted to the subsidy (RHI) being a farmer of course !!
It will be insulated well ( to current building regs) ; but just worried it wont have enough hot water /heat etc as it may be holiday cottage thanks:D

Hi

Okay, you've described string, now how long is it ??

What are your calculated heat losses at 22C difference between internal and ambient ??

What size ASHP are you looking at ?

Where are you (calculation of av winter temperatures etc) ?

Are you considering daytime or nighttime ASHP usage (EconomyX ?) ?

I agree with mankysteve ..... insulate well over building regs ...... if there is a loft, shove at least 500mm of insulation in it and get an overall U value of around 0.09W/m2/DegC (or better) ...... fill every possible unnecessary gap to keep the cold air out & warm air in ..... address the wall insulation as best as possible, and if it's a total restoration dig out the floors and lay as much underfloor insulation as you can fit in without the foundations collapsing ..... you can then start thinking about the windows & when that's done you'll have an idea how much heat you'll need and then what the source could be.

There is no chance that you will get a barn conversion to passivehaus standards but if you can get below 4x passivehaus on heating requirements (target around 60kWh/m2/yr or below) then you'll be doing very well ....

HTH

hellogboy

Well I can answer some of those; it is a 8.5 kw ecodan that we are proposing. Not sure about the heat loss calculation but Insulation wise we are putting on the walls 25mm air gap then 75mm x 50mm stud wall fixed back to wall then 75mm kingspan between studs, finished off with a 52.5 mm kingspan kooltherm insulated dry lining board
At the moment we are going to put in 100mm kingspan in the floor and 300 mm rockwool on the roof space but I guess it would take more there !
Location near Tow Law , County Durham. Electric wise we are hoping to get the turbine up fairly soon

zeupater

hellogboy wrote: »

Well I can answer some of those; it is a 8.5 kw ecodan that we are proposing. Not sure about the heat loss calculation but Insulation wise we are putting on the walls 25mm air gap then 75mm x 50mm stud wall fixed back to wall then 75mm kingspan between studs, finished off with a 52.5 mm kingspan kooltherm insulated dry lining board
At the moment we are going to put in 100mm kingspan in the floor and 300 mm rockwool on the roof space but I guess it would take more there !
Location near Tow Law , County Durham. Electric wise we are hoping to get the turbine up fairly soon

Hi

Not the warmest part of the country then !! .... I used to travel to that area quite regularly at this time of year, that's if the A66 was clear .

I'd suggest that you do get some heat loss calculations done, even if they're quite rough ..... 8.5kW isn't a lot, it'll probably be enough to cope with heatloss when the property is up to a decent temperature, but I'd guess that you'll need something else to initially warm the thermal mass of the building and cope with extreme conditions (like now) ..... log burner planned ????

Remember also that the efficiency of an ASHP will fall substantially as the outside temperature falls away, whereas a GSHP will maintain a more stable efficiency .... weighing the cost of ASHP energy against the cost of a GSHP ground loop over a period of time it could possibly work out cheaper to install the ground loop if you have the room/funds available, this should be looked into and considered ....

HTH

hellogboy

Log burner is part of the plan ; ground source could only be done with borehole as building is actually on the edge of my land; and yes I must admit cost is a factor because by the time you add in the UFH on to the ASHP it would easily exceed a 'traditional' oil and rads system. Thats why I am keen on the RHI payback. I think it is an easier choice when you go from scratch as well
Also most builders / installers are fairly new to this and there are stories of them being ripped out etc where they havent worked as planned. I will hopefully see one installed before I take the plunge: although nobody has rushed forward to show me one in this weather yet ! though I did ask my chosen installer the other day to sort one out to look at
.:beer:

Catbells

Hi - Have just posted a query about ASHP and thought to share with you the information I was given yesterday by an installation company (can't remember name but if you want it I will dig it out). I was informed that the Government are bringing in new incentives in June next year and will reimburse the cost of the pumps over an 18 year period. This is after a cessation of all grants last year. The order and installation can be (I was told) begun now and the incentive will still be available.

hellogboy

Update!
; heat loss est. 50kwh/m2per year
Just seen a bigger Ecodan with solar panels and full UFH in a new build very impressive . Still warm during the recent cold snap and averaging £2 a day electric use from the ASHP.

daytona600_2

big recalls on mitsibishi ecodans this year
especially in recent cold temp

d

hellogboy wrote: »

Update!
; heat loss est. 50kwh/m2per year
Just seen a bigger Ecodan with solar panels and full UFH in a new build very impressive . Still warm during the recent cold snap and averaging £2 a day electric use from the ASHP.