Danfoss FHV-R Underfloor Heating Valve Query...

[machineage]

Just wondered what UFH installers think of the Danfoss FHV-R:

http://danfoss-randall.co.uk/xxTypex/207541.html

I just wondered what the consequences would be of it allowing water at temperatures of +80 Degrees C into the UFH Pipe? I was always led to believe that anything above 55 Degrees was an absolute no no

I would be using it for a bathroom covering an area of no greater than 5sqm's.

Would appreciate any thoughts.

Thanks!

 

[Norcon]

If the flow temperature is 80c and the return on the sensor set to 50c then an average of 65c!
Not what you want with ufh.

If return set to 20c then 50c average. Just acceptable.
There is a greater potential for the floor surface temperature to rise above the recommended maximum of 29c with this valve.

Double meander pipe layout is important!
I've never fitted them so cannot say how they preform.
It provides the same function as the FJVR afaik except the unit is placed directly in the room. They use the same sensor.

 

[machineage]

Hmmm - I'm just not sure

I had a reply from Danfoss saying as long as the pipes were in a minimum 75mm screed and layed in a snail type pattern then they were confident there would be no damage to the floor

Anyone here actually installed one of these and have some in-situ experience?

Thanks

 

[Lochy]

Fitted a few mate & you are very limited with the floor area with them, not that it's the case with you.

Completely daft having a floor surface area above 29*C by the way. Fit towel rails, radiators etc, even on the UFH loop is much, much better.

 

[machineage]

Hi Lochy

Thx for the reply...

Had wondered about feeding the UFH pipe from the outlet of a towel radiator to lower the UFH pipe inlet a little. Is that what you are suggesting?

 

[Lochy]

Hi Lochy

Thx for the reply...

Had wondered about feeding the UFH pipe from the outlet of a towel radiator to lower the UFH pipe inlet a little. Is that what you are suggesting?

No, towel rails or radiators can be part of a temperature controlled loop, if you need to increase the heated surface area. Don't have your floor too hot, that's not comfortable.

 

[machineage]

Hi Lochy

Yes I had already planned to have a large towel rad in the room to provide most of the heat requirement. I wanted to use the Danfoss valve & sensor with UFH pipe to raise the floor / tile temperature.

I liked the idea of it being simple with no need for an additional electricity consuming pump. I wondered if it could be turned down to such a level that it would merely take the chill off the tiles...

I have considered underfloor electric cables / mats too.

 

[Lochy]

The FHV-R will be fine, just ensure you have enough heated surface area to heat the Bathroom.
Electric UFH is mince & very expensive to operate.

 

[machineage]

.
Electric UFH is mince & very expensive to operate.

Yes that's the conclusion I came too hence looking for a wet alternative!