UFH on First Floor

[DeanAlan]

Hi folks,

 

As part of a major renovation and extension we are working hard on airtightness and insulation - not passive house but expect to significantly exceed building regs - and putting Wet UFH within screed on new ground floor and considering upstairs. Not putting rads in! Either Wet UFH (clip plat system fit from above) but also considering whether we need to.

 

Was wondering about whether we need UFH/Heating upstairs at all and wondered what others peoples experiences / thoughts were.

 

Bedrooms should generally be a little cooler than general living spaces (all downstairs).

Roof imsulation will be good (300mm at least) and very good airtightness.

Have been considering IR Rads/Towel heater in en-suite and master bathroom (both upstairs).

 

DO you think we could get away with no first floor heating and just rely on good insulation and warmth flowing upwards?

 

cheers,

-Dean

[Bitpipe]

You can definitely get away with it in a passive standard house - we only have low temp UFH on ground floor and towel rads / electric UFH in upstairs bathrooms. We like the bedrooms cooler but they warm up quite quickly when occupied.

 

However in a retro fit it will all depend on how close you get to the passive values for insulation and airtightness, plus quality of your windows (triple glazed, passive standard seals, tapes to frame etc...)

 

Ultimately you will need to do some modelling and see what the numbers tell you.

 

Will you have a MVHR system?

[DeanAlan]

Thanks @bitpipe

 

Yes MVHR system.

We're retrofitting an intelligent membrane (Passive Purple) in existing (solid brick construction + new EWI) and on SIPs extension (the extension is 130sqm compared to the existing 86 sqm).

Double glazzed aluminium windows, not triple.

Could potentially go through 1 winter and see how we get on. We may be living in a building site for a while as it is, I could just leave the floors bare for a while so I don't damage any decorative flooring if I lift the decking and put in UFH later.

[Weebles]

We also have no heating upstairs except electric ufh (used in winter) and towel rails (rarely used) in the bathrooms.  It drops to around 15-16 degrees in the bedrooms in mid winter.  We get some circulation of air via the MVHR and rising heat from downstairs but we notice that the room on the end of the house with three external walls (and a bit of external floor as there is a small cantilevered section) is a bit cooler than the rest of the upstairs (furthest away from the stairwell too).  Not a problem but your layout is something to be aware of.  Personally I find that room a little chilly sometimes.  We have triple glazing and passive house standards.