UFH pipes in the walls, not floor? Silly idea?

[Gone West]

1 minute ago, Onoff said:

Doesn't MVHR itself "create" convection currents?

Certainly not significant if set up for PH ventilation rates.

[Nickfromwales]

27 minutes ago, PeterStarck said:

If our house had been larger we could not have used our system.

I think this is the important piece of this particular 'puzzle'. For a smaller, or certainly a single storey dwelling, the heat loss is far more manageable and therefore requires much less effort to offset it. 

Could you just remind me of the exact makeup of your ground floor from the earth up please? I am very interested to hear that you find the stability and relationship between the floors / walls / windows all seem to be relatively indifferent, and I assume this is attributed to by not turning the 'heating' off for any extended periods, instead favouring long low heat influx via the Genevex. Also, do you have an indication of what temp the dwelling will naturally reside at if you shut the heating off ( eg what was it performing like prior to commissioning the heating and setting it to work ) ?

Sorry to keep singling you out Peter, but yours is an interesting case study and examines the possibilities that lay away from the generic lines of thought.  

The case I referenced is manageable, with the points I've highlighted vs the crap that the MVHR supplier first spewed out without proper review, but does indeed require auxiliary emitters to achieve it. Me personally, I'd have gone for wet UFH in plates because thats the entire ground floor done and dusted, plus they require wet heating to supply the bloody feature rad and towel rads anyway so my thoughts are that in a bigger dwelling its a bit perverse. 

IMO MVHR should be left to be MVHR, with just the selective addition of maybe a 'geothermal' brine loop for some passive energy input. In a PH you're never that far away from comfortable and 'climate control' should remain within reasonable grasp ( if you haven't made a greenhouse with all the glazing that is  ).   

[Gone West]

15 hours ago, Nickfromwales said:

I think this is the important piece of this particular 'puzzle'. For a smaller, or certainly a single storey dwelling, the heat loss is far more manageable and therefore requires much less effort to offset it. 

 

Although from what I've read designing a PH bungalow is very difficult, although it's something I've yet to try.

 

15 hours ago, Nickfromwales said:

Could you just remind me of the exact makeup of your ground floor from the earth up please?

The ground floor makeup is:-

Earth

200mm compacted type1

50mm compacted 4/8 granite fines

300mm EPS300 (Peripor)

200mm RC 30/35

Porcelain tiles

There is a 200mm thick EPS300 upstand around the slab.

 

15 hours ago, Nickfromwales said:

Also, do you have an indication of what temp the dwelling will naturally reside at if you shut the heating off ( eg what was it performing like prior to commissioning the heating and setting it to work ) ?

I can't say because it's dependent on the outside temperature and amount of sun. Last winter before we had the electricity connected IIRC it used to be around 16C/17C first thing in the morning but I don't know what the weather was like.

 

15 hours ago, Nickfromwales said:

IMO MVHR should be left to be MVHR, with just the selective addition of maybe a 'geothermal' brine loop for some passive energy input.

I like the idea of the small ASHP being incorporated in the MVHR as it's a neat solution which could be increased in size for larger PH buildings.

Edited August 29, 2018 by PeterStarck

[Nickfromwales]

32 minutes ago, PeterStarck said:

I like the idea of the small ASHP being incorporated in the MVHR as it's a neat solution which could be increased in size for larger PH buildings.

I'd say yes if larger bore radial ductwork or radial ductwork with multiple room inlets are used. Eg higher flow rate, less noise, better dispersion. Where problematic I'd look at low level plenums. Would also lend itself to not having taller 'beefed up' joists aka ????