Geothermal/UFH questions

mrsloftus

Hi there, our new build is under construction. It’s a bungalow, approx 2800 sq ft. We are pumping the 4” cavity with ecobead insulation and dry lining the external walls with 50ml insulation attached to 12ml plasterboard. All our windows are triple glased. We are debating the best type of heating system to install but a thousand opinions later we are more confused than ever. I like the idea of geothermal heating with UFH throughout due to having no rads and no oil. We have just received a quote which seems reasonable enough but I’d like to know whether the finer details are sufficient for our home heating and hot water needs, i.e.:

UFH – 1600 meters of PEX-AL-PEX Pipe
Heat Pump – Stiebel Eltron WPF 12 S Geothermal Heat Pump delivering 12 kW, 6kW electric backup.
Hot Water System – 300l Thermal Store

shane0007

That 6kw back up will be on a lot. Equivalent to 2 x electric kettles continuously boiling.... Nice elecky bills!

fairwind

hi
we are also hoping to build soon 250 sqm a3 .
also lookin at geothermal as really if put in and sized properly is most efficient by far -if u subtract cost of efficient burner and yearly service costs to install hp about 9500 -pay back 8 -10 yrs if u get a good cop.
we r looking at ashgrove company with nibe prop 12 kw 1245 fighter system hpump -apparently gives cop of 4.8-ie ikw electric makes 4.8kw at certain temp-i think 7 degree to 35 deg[low output space ufh]conversion of heat energy]
important i think to size it for ur heat demand the DEAP figures done now preplanning should show u ur total kwh per yr.example for ours 6500 .divide this by 365 days 17.3 rough and then divide this daily heat req by 2 [ie only needed for 12hrs of day] and for us this worked out at 8.7kw hpump but remember u also need hot water [55 - 60 degree]]so u either add a 2 - r exra kwatts or add electric immersion backup.
would u mind letting me know ur quotes by pm so we can compare and also ur company details?

f