Should wet UFH be considered a primary or secondary source of heating?

[u587162]

As we gutted out our whole house and rebuilt it / rennovated it, most of it has been well insulated as far as I can tell, but I am being told by some bathroom shops that wet UFH should only be considered a secondary heating supply and not primary (we dont plan to have any radiators) across all three floors.

Is this true? I think we we will go for 150mm pipe centres and an overlay systems on the first and second floor but screeded system on the first floor where we will also have a wood burning in the main living room.

Just a a little concerned by the comment that it should not be used a primary heating solution.

 

[tomfe]

Is the bathroom shop trying to sell you radiators?
You might need a heatloss calc to determine your temps and centers but your ufh supplier can do them. As long as you have insulated to at least current building reg levels 200mm centers will be fine, so 150mm will help if you are under that

 

[u587162]

No they won't trying to sell me radiators, just giving me advice when I asked them about towel radiators having the ability to connect to a UFH water supply. Got a bit concerned afterwards.

 

[tomfe]

To answer your op title question then, UFH is mainly used as a primary source of heating. What would be the point installing UFH and then adding radiators to each room, that's just madness.

Normally bathrooms do not have the required floor area to heat the space, so you add a towel rad.
If you have well insulated your house and I mean well (u <0.15) then normally you will just have underfloor heating in the bathroom floors to reduce the chill of the floor thus eliminate the need for a rad. And if it's on the first floor then you might not need any at all.
Depending on your setup you might need a separate loop for towel rads.

You did not specify where the ufh was going just mentioned the bathroom shop, are you just on about bathrooms or the whole house?

 

[endecotp]

They might be thinking of electric bathroom UFH.

 

[^woody^]

Is the "bathroom shop" the best place for advice on central heating systems and performance?

 

[theprinceofdarkness]

The problem is not in winter, its in summer. Just been speaking to my S-I-L on this subject, she turns off all her rads, except the bathroom one!, Err I can't see that being economical at all. Don't ask what the room stat is set to, most houses are hovering at 20*C in this weather, so perhaps the rad comes on at night and tries to heat the house?
I always fit an infra red electric heater, gets the en-suite/bathroom comfy in 5 mins. Same reason to use an electric towel rail. Wet UFH has such a long warming up time that it needs to be run almost all the time- 1 hour warming time? and needs the rest of the central heating turned off and you get heat losses in the pipework. Electric UHF, warming time shorter, no pipe losses but higher running costs in the winter. I think a good arrangement might be to use electric UFH with a timer, so its only on for an hour in the morning ( say 0600-0700 for use at 0700-0800) and a similar time at night.
All in all a lot depends on where your bathroom is and the insulation quality of the house that will determine how much heat you need and when.
Frank

 

[u587162]

Sorry just saw these replies and didnt get the notification. Firstly the bathroom shop is also a plumbing shop.

I was referring to wet UFH for the whole house across three floors, in bedrooms and bathrooms.

Is it ok to install a stainless steel towel radiator on the same circuit as the UFH in the bathroom?