Ground source heating in a new build

[KB6930]

Ground source heating in a two storey house how well would under floor heating downstairs work then radiators upstairs it would be very well insulated etc?

 

[Lincs Lass]

It works very well, one near me had it but they used beco blocks internally and faced with stone, it's a big house and has plenty of ground to bury the pipe work

 

[KB6930]

Should've said this would be a timber frame house

 

[Lincs Lass]

Timber has excellent insulation properties ,lag it well ,it will be toasty

 

[Exfarmer]

Apart from the bathrooms, I see little need for heat upstairs

 

[Farmer Fin]

I built a new house a few years ago and looked at air and ground heat source but was wary. In the end managed to get planners to let me have an oil boiler as house is well insulated. Timber kit is probably easiest to insulate. Spray foam insulation is coming on leaps and bounds and gives an air tight house. I put rads in all upstairs rooms (against architect advice) as it added little cost when building. Glad we did as we use them for 4 months of the year.

 

[KB6930]

Apart from the bathrooms, I see little need for heat upstairs

I'm kinda of the same thinking but living in a cold house I think putting in rads and possibly electric under floor in the bathroom to warm a tile floor would be a good idea

 

[Farmer_Joe]

GSHP tend to stay on constantly, ive got rad up and down stairs with towel rads in bathrooms, i would definately advise some form of heating in them.

As my house stays at constant 20 deg its always nice and warm on tiles in kitchen and bathroom even though there not heated, mines converted barn so was insulated as new build, 100mm kingspan in floors which stops floors from getting cold.

 

[dirty harry]

Ashp here & was thinking the same as you 5yrs ago but went under floor down & up, yes was a bit dearer than up stairs smart rads (maybe +20% mostly in labour ) but well worth it in long run, put furniture where you want no hot spots etc and at the time to get the heat output from ashp we needed “smart rads” which were big & bulky etc
Good luck with it!
Cheers dh

 

[Hard Graft]

Go with under floor all over so You can have a lower water temp exiting the gshp A’s it is more efficient at low temperature

 

[KB6930]

Anyone got any experience of UFH and posi joists for upstairs?

 

[steveR]

Anyone got any experience of UFH and posi joists for upstairs?

Yes.

Ask away or PM

 

[dirty harry]

No problem just lay the pipe on top after posi joists lay your mdf floor as normal then we laid our pipes in pre grooved (soft plaster type material) trays (bit of a faff yes!) then a thin 6mm iirc ply on top job done . This is where most of the extra cost came from but did a fair bit myself but well worth the effort long term - and as mentioned above you’ll get much more efficiency from the gshp
Cheers dh

 

[KB6930]

Yes.

Ask away or PM

Which method did you use above or below floor level?

 

[steveR]

Bonded plywood deck on top of webjoists, although the moronic builders failed to bond the floor panels to the joists, which has caused problems ever since! However, this has not affected the UFH. The pipework is fixed to the underside of the floor deck with metal spreader plates.

I did contemplate the use of a screed floor upstairs as well, but only for about 5 minutes, although the large thermal mass would compliment the low temp UFH system from a heat pump, as it downstairs!

The system as described by @dirtyharry would be good I imagine as it creates mass. Easier to self fit too as you are working on top. I imagine 6mm ply would be a tad thing for tiling onto afterwards mind...?

 

[scotston]

An air tight house is as important as a well insulated house. Imagine sitting in a room made from 300mm kingspan but there's a 5mm gap between joints. Pointless but you can still claim the room is well insulated. If you build a well insulated two storey house that's air tight, you can substitute the upstairs heating installation for an air handling unit to move the overall house specified heat requirement around in an even fashion. Even though the overall heat requirement comes from ufh in the ground slab. Yer heat pump will love you for it and it easily give you 400%, even air source minus 5 outside.

 

[KB6930]

Thanks for the replies folks it's given me even more to think about.

 

[Hfd Cattle]

we built a green oak house 3 yrs ago . GSHP with underfloor heating downstairs and up. Many said don't bother with up but we glad we did . We never use it in our room but both bathrooms are on all the time and it's surprising how many of our guests are a 'lot more nesh ' than us and want a bit of heat in their room . Think carefully where you are putting your cupboards in the kitchen as you may not want to put it where they are going to stand . Our kitchen only has UFH down the middle of it ,3ft in from each sides .

 

[Dave645]

I did UFH upstairs with UFH pipes over the floor, and dry screed using tile lates as spacer and to allow for over plying after it was done, I also fully glued the top ply down to ensure a squeak free floor.
My insulation was put under the floor which was an all weather one put in during the build which stood open to the weather all winter after we had 3foot of snow and low temps for 2 months.
sure It’s all more work but, it was done by me and a couple of mates as there are no hard jobs just time consuming ones, the actual pipe laying for a 100m2 floor only takes a few hours it’s the prep like putting the tile lates down to the design and the screeding, and over plying that takes time but the materials cost are next to nowt, pipes are cheap lates are cheap, sand and cement are cheap the over ply was cheap the only thing that is a little expensive was the floor glue but it did make the floor silent. And maybe only a few quid a m2 all told. I used the same glue to fix my engineered timber floor on my ground floor liquid screed covered UFH pipes.

 

[akaPABLO01]

Install it

radiators work fine if designed correctly