UFH with Rads upstairs question

whitelightrider

Hey guys,

Looking for some advice. We are just building a 2200 sq ft house in Galway. We are putting UFH downstairs and we had initially decided to put it upstairs as well. However after talking to a few people I am not going more towards Rads upstairs for the simple reason that if the rooms are cold upstairs we can just turn up the heat. Whereas if we went with UFH it could take 3 - 4 hours to heat them.

Just looking for opinions or advice on what would be the better option.

ircoha

I suppose u have answered your own question in a way but then the question needs to be asked why UFH downstairs if the long lead time is the key detracting issue upstairs.

The obvious concern is that UFH takes water at much lower temp than normal rads so if going rads with ufh water temp could require big rads for the same out put.

Can u give some details on house: TF/ concrete floors/what?

ps glad to help on elec shower

sinnerboy

OP - many , many clients of mine have done this - it works fine , no worries

ircoha

sinnerboy wrote: »

OP - many , many clients of mine have done this - it works fine , no worries

SB: what's ur preferred source of energy for this mixture and at what temp do both systems run?

whitelightrider

ircoha wrote: »

I suppose u have answered your own question in a way but then the question needs to be asked why UFH downstairs if the long lead time is the key detracting issue upstairs.

The obvious concern is that UFH takes water at much lower temp than normal rads so if going rads with ufh water temp could require big rads for the same out put.

Can u give some details on house: TF/ concrete floors/what?

ps glad to help on elec shower

Thanks ircoha. We were looking at rads upstairs so that if the room was cold in any way we could give the heat a quick boost to the rads where as ufh would take longer to heat. We prefer ufh downstairs because it'll be a living area and probably easier to time when people will be in this space.

The house is block with hollowcore between floors. Insulating external walls and pumping the 4" cavity also.

whitelightrider

ircoha wrote: »

SB: what's ur preferred source of energy for this mixture and at what temp do both systems run?

Sinnerboy, what would you use for this type of heating? We were looking at going with gas as it seems to be better with UFH. But not that we are going to mix UFH with Rads would gas still be the better option?

sydthebeat

UFH operates at lower temperatures than conventional rad systems.
Oil and gas are not the best fuel as these burn at high temps, for best results you should use a fuel that is more efficient at lower temps such as geothermal or wood pellet......

whitelightrider

sydthebeat wrote: »

UFH operates at lower temperatures than conventional rad systems.
Oil and gas are not the best fuel as these burn at high temps, for best results you should use a fuel that is more efficient at lower temps such as geothermal or wood pellet......

Gerthermal is way too expensive at the minute and until the quality of wood pellets improves I wont be going with them either. Also we simply dont have the space to store these in bulk so it's either gas or oil.

paulff

If you need to go with rads upstair then use Alu Rads.
There are means and ways too to reduce that 3/4 hour delay for UFH upstairs: run unsulation around all internal walls/ perimeter walls, reduce upstairs floor screed thickness down to say 50mm by using a liquid screed (like easi screed, NOT ready mixed concrete)

sinnerboy

whitelightrider wrote: »

Sinnerboy, what would you use for this type of heating? We were looking at going with gas as it seems to be better with UFH. But not that we are going to mix UFH with Rads would gas still be the better option?

Condensing gas or oil boiler . With gas being the preferred option .UFH manifold can bring temp of water from boiler down by mixing with cold .

Bobby04

paulff wrote: »

reduce upstairs floor screed thickness down to say 50mm by using a liquid screed (like easi screed, NOT ready mixed concrete)

Hi paulff, I never heard of easi screed before, but sounds very interesting. I presume it can be used downstairs also to reduce screed depth?? And how does it perform with regard to expanding and contracting ie. does it crack easily?

The reason I ask about using it downstairs is that at face value it sounds like an excellent way to reduce response time for UFH. But having said that, my UFH takes only about 1-1.5 hours to have a noticable effect on room temperature. These figures of 3-4 hours (and even a day mentioned in other threads) I can only guess are for poorly designed and/or installed systems.

whitelightrider

Bobby04 wrote: »

Hi paulff, I never heard of easi screed before, but sounds very interesting. I presume it can be used downstairs also to reduce screed depth?? And how does it perform with regard to expanding and contracting ie. does it crack easily?

The reason I ask about using it downstairs is that at face value it sounds like an excellent way to reduce response time for UFH. But having said that, my UFH takes only about 1-1.5 hours to have a noticable effect on room temperature. These figures of 3-4 hours (and even a day mentioned in other threads) I can only guess are for poorly designed and/or installed systems.

Hi Bobby, I guess its more a fear of it taking that length of time to heat upstairs being the reason Im looking at rads. 1 - 1.5 hours is a more realistic timeframe for the rooms upstairs to heat. Ill talk to my plumber today and ask him for a realistic timeframe to heat the rooms using the under floor.