Wet Underfloor Heating Off Standard Boiler

[Ajax123]

Didn't know where to put this one and think this has probably been asked before but here goes

I am in the process of building a loft conversion at the moment. I have been busy insulating the heck out of the roof which previously didn't have any insulation at all. The winter prompted me to do it. Anyway, I have a standard central heating system running off of an oil fired range boiler. Instead of putting a radiator up there I want to put some insulation under the floor boards and then some pipes down under the floorboards as well to act as underfloor heating. I want to use a standard Thermostatic radiator valve to switch it in and out. As the pipes will be running at around 75degrees C flow temperature I wil not need so much pipework.

Can anyone think of a reason why this would not work.

 

[Alan.P]

Mmmm, only drawbacks I can see is heat on surrounding materials, and load on the pump pumping to that hight along with boiler limits.

Sorry that's not very insightful but all I can come up with.

 

[DHTiling]

Might be best to ask our fellow plumbers..on our sister forum.

Plumbing Forum speak to Migoplumber( shaun) and say i sent you over.

 

[Ajax123]

Mmmm, only drawbacks I can see is heat on surrounding materials, and load on the pump pumping to that hight along with boiler limits.

Sorry that's not very insightful but all I can come up with.

got no issues with the boiler or the pump capacity as it was always sized with the loft conv in mind. As for heat on materials the only thing O can think is it might dry things out a bit.

 

[faithhealer]

just read about a valve you can fit without the need of a manifold but thats as far as my knowledge goes

 

[Ajax123]

just read about a valve you can fit without the need of a manifold but thats as far as my knowledge goes

come on then faith give us the link....

 

[faithhealer]

come on then faith give us the link....

this was in one of the plumbing and heating mags in the plumbers merchants will ask about tomorrow

 

[Dave Ramsden]

Im still not convinced the boiler can pump that much water that far that fast and not overload...

 

[Ajax123]

Im still not convinced the boiler can pump that much water that far that fast and not overload...

The boiler currently runs at around 50,000 BTU. It has a capacity of 80,000 BTU. When I installed it I made sure i had plenty of capacity. I will do some calcs on the heat loss and pipe size etc before I go ahead but am fairly confident it will be fine. I ran the main trunk pipes in 28mm copper and branche pipes in 22mm then each rad is on 15mm so I should be fine to get enough heat and water up there. It is only about 10 feet aboive the current highest point any way.

 

[Scott]

Pump should be ok, no different to having a three story town house. If it was head pressure 10ft or 3mts equates to 0.1 bar, so to pump it up that high wouldnt be much more.

 

[Scott]

BTW running the pipework the way you have with 28/22/15 is the correct way to do it so this should help with the efficiency of the system. If only everyone did it the right way!

 

[Ajax123]

BTW running the pipework the way you have with 28/22/15 is the correct way to do it so this should help with the efficiency of the system. If only everyone did it the right way!

I read readers digest DIY before I did it....

 

[Scott]

We all have to learn somewhere

 

[Ajax123]

We all have to learn somewhere

that's the one. They even say PVA for primer for tiles :yikes:

 

[Scott]

:yikes: Phew, thats a page i didnt read!

Currently about to convert our bungalow to chalet with four bedrooms and 2 bathroms in the roof, that book will be taking a real bashing over the next few months!