Underfloor Heating setup

[Mike2007]

I have a small section of underfloor heating to install. Do I need to buy and setup a big manifold or can I use a TRV and locksheild, which do the same thing essentially.
Floor area 3m X 4m.

Thanks

 

[Bahco]

It will be more like a sauna with a TRV perhaps!

U/F has to be controlled with its own thermostat as the temps are much lower than space heating.

You should phone the manu for advice,

 

[kevplumb]

can I use a TRV and locksheild, which do the same thing essentially.

NO

you MIGHT get away with a zone valve and separate stat

 

[Saltire]

Try Polypipe or Hepworth, they do underfloor packs for single rooms... Underfloor circulates water at a lower temp than the water in your rads..

 

[Mike2007]

Its about 50 degrees for UFH isn't it ? What temp is TRV set to 1 or 2 setting.
basically its "start flow" "satisfied" "stop flow". I think a room stat and zone valve would do a nice job on one room.
Was thinking of polyplumb "Overlay" on concrete slab floor.

 

[WDIK]

no it doesnt work like that, yes 50c max, but you need blended with return to keep the temp lower than the rads.
a whole different concept, a trv will just stop start high temp water and damage your floor and feet.

 

[billy bob]

A TRV works by room temperature, it does not control flow temperature, you need a blending valve for UFH

 

[Mike2007]

Thanks for that, has sorted that out, a blending valve (manifold) it is. Hope I can get one with maybe two flow two return, as most I have seen are huge (8 flows, 8 returns)!

 

[Balenza]

I have a small section of underfloor heating to install. Do I need to buy and setup a big manifold or can I use a TRV and locksheild, which do the same thing essentially.
Floor area 3m X 4m.

Thanks

Use a Danfoss FHV-R
http://heating.danfoss.com/PCMPDF/VD.UI.C3.02.pdf
Operates similar to a TRV.
Restricts flow on sensing a temperature rise.
You could call it a T-FHV (Thermostatic Floor Heating Valve) if you like.
Suitable for floor areas up to 15 sq meters. As their is a co-relation between the floor surface and the room temperature , the room temperature will be held, more or less, at a constant level.
Cost is about £45 for this valve.

The FHV-A works in a similar way except it is designed for mixed temperatures and acts like and replaces the normally used electrical room stats giving proportional flow control to the particular area it is sited in.

As the FHV-R uses the higher temperature flow from the primary circuit this will have the effect of boosting the re-heat period from cold.
You will still have a delay though especially if you embed the pipes in a deep screed.
A double meander UF pipework pattern is essential for this layout.

 

[Mike2007]

Very interesting, so there is a product available for small UFH areas!