BlueJohn
wibbled on Saturday 09 January 2010 17:57

sets the temperature of the water for the UFH. Ours is currently set
on the lowest setting (about 35 degrees I think). If you put you hand
on the manifold, it doesn't feel that warm - it is just below body
temp! For our room, Polypipe suggested a temp of 52 degrees. Maybe
yours is set too low?


Ours is set to maximum. I've no idea what temp it's running at, but he
manifold feels almost at medium-ish radiator heat.

Normally you wouldn't want it too hot in a solid floor as you risk cracking
the screed - but as yours is in a suspended floor, there's less risk.

In terms of heat output, when the pipes were laid, do you know how
close together they were? Obviously the closer they are the more heat
you will get out from them.


They were the standard width from the manufacturers as they were set
in to insulated boards - about 6 inches apart.

Are they set into heat spreader plates?


Also, how long have you had the heating on for? I have the pipes laid
in a concrete floor and it takes a good day (or longer) for it to heat
up with the UFH on continuously.


It turns on in the morning at about 7:30, it goes off at about
11:00pm. Never have I seen the thermostat on the wall (the one that
controls the UFH) rise above 17C, and it's set to it's maximum of 25C.

It is a bit deceiving as the heat is very subtle it is nothing like a
scorching radiator but if your room doesn't get above 17 degrees,
something doesn't seem right.


If "subtle" means "running it for 12 hours at apparently maximum
output and we feel next to no warmth" then yes, it's subtle alrighty.
About the most subtle use of £1,800 I've ever spent in fact.

BTW this is wet (not electric) UFH and it's in bats suspended between
wooden joists (not in concrete/stone).

The solid floor UFH is normally ready reckoned to give about 100W/m2 but I
have no idea what a suspended floor system is like.

What have you got between the pipes and your feet? Wooden boards and carpet
for example?

--
Tim Watts

You know you need more insulation when the snow blanket on the roof makes
the house 3 degrees warmer...