Recommended brand for a wet underfloor heating system

tallac

I've just warmed up (no pun intended) to the idea of getting a wet underfloor heating system. I'm planning to get a system boiler (not sure which brand yet, but a reputable one) with a hot water storage tank (most likely a megaflo).

Are there any good brands or market leaders of a wet underfloor heating system? Or are they fairly as good as each other?

Mutton_Geoff

Wet UFH is just a length of plastic pipe. The magic is done in the manifold. I use John Guest stuff, it's made very well. For that reason, I then also use their brand of pipe (lay flat) as I know it will fit the connectors properly.

fenwick458

one way to save money is don't bother putting a thermostat in every room. all ground floor UFH in my house is on one programmable stat and it works fine. 

ComicGeek

Most important thing is to get it sized correctly. There should be a detailed heat loss calculation and pipework layouts to calculate the heat output from the system based on proposed floor coverings.

Pointless spending lots of money on it if you can't get enough heat out of it. Also no point buying too much pipework if you don't need it.

Far too many people just throw it in and hope for the best.

tallac

ComicGeek said:

Most important thing is to get it sized correctly. There should be a detailed heat loss calculation and pipework layouts to calculate the heat output from the system based on proposed floor coverings.

Pointless spending lots of money on it if you can't get enough heat out of it. Also no point buying too much pipework if you don't need it.

Far too many people just throw it in and hope for the best.

I didn't think about the heat loss and type of floor covering aspect. I assumed the pipe spacing was standard regardless of the floor covering. Isn't the temperature of the system controlled by the thermostat though? Obviously, pipe spacing needs to be sensible but the thermostat will allow a reasonably wide range of heating temperatures, no?

ComicGeek

The closer the pipe spacing the higher the system heat output - but this still has to take into account the flooring type and the maximum surface temperature without damaging it, which might be 27 degrees Celsius. Depending on what areas you can't install pipework under (ie toilets, kitchen islands, built in furniture etc), you can then calculate how much heat output you can get from the system.

So if you've worked out that you need 100 W/m2 heat output, but your UFH system can only deliver 50 W/m2, then you have to achieve this with an additional heat source - there's no more heat you can get out of the UFH system once you've minimised pipework spacing and maximised flow temperature. The thermostat can control heat output, but only up to the maximum heat output from the system. The heating requirement will depend on insulation standards (particularly underneath the UFH pipework), air tightness, any extract fans or open chimneys etc.

Rodders53

Retrofitting UFH to a building is fraught with danger. 
It's bad enough when designed into the building from new.

One thermostat throughout a building is a very bad idea. 

Our kitchen-diner needs heating more than the Living Room - and that gets residual heating as all the UFH pipes run through it to the other rooms and you can't stop that heat gain and still heat the other rooms!

Don't expect it to work like conventional wet heating.  Think more like Economy 7 storage heating.  If your bedroom is near/over the boiler do you want to be woken by it at 4am (or earlier) so you can go down to a reasonably warm room at 7.30?

Ideally the UFH wants water circulating pretty much all the time, at a low temperature.

You need to read up and understand the design concepts of UFH before going down that path.  Trust me. I'd not want it ever again.

theonlywayisup

fenwick458 said:

one way to save money is don't bother putting a thermostat in every room. all ground floor UFH in my house is on one programmable stat and it works fine. 

It doesn't work in a large barn like us, we are sprawled over a long area and if we didn't zone we would be heating every room to one temperature.  Madness, so horses for courses.  Don't cut corners on a few stats when it could cost much more in the long run.   We have a stat in every room and every hallway. 

tallac

To add some context, I'm only considering UFH at the ground level. There's a large open plan area which covers kitchen, dining and a chill out sofa area. There's a few other rooms downstairs as well. I was thinking of breaking out the zones as follows:

Zone 1: open plan area + hallway
Zone 2: living room (this is a separate room to open plan area)
Zone 3: office/study room (also a separate room)

I would want to have each of the zones independently temperature controlled and set up on its own timer schedule.

Rodders53 said:

Ideally the UFH wants water circulating pretty much all the time, at a low temperature.

Are you suggesting that the UFH is left on (on a low heat) even through the night and during the day when no one is home? So instead of turning it off when you don't need heating, you'd turn it to a low temperature?

tacpot12

Have a look at the length of the guarantee that the manufacturers provide for their different pipes, this will give you an idea on the relative quality of the different pipes. And beware of manufacturers who make it difficult to find out how long the guarantee is - if they don't publish this in a readily accessible place, they don't deserve your business.
This pipes are the most important part of the system as access is always likely to be a problem along some of the route, and you can guarantee that the pipe will fail at the trickiest point to access (Murphey's Law, Sub-section 3a). 
There is a very good guide to Underfloor Heating here: 
https://www.johnguest.com/speedfit/product/pipe-underfloor-heating/speedpex-barrier-pipe-in-coils/