I am renovating a house with a very small hallway (900 x 900) and nowhere to fit a radiator (1 external door, 2 internal doors and a staircase off it).

For this and other reasons (including the fact that I am planning to heat with an air source heat pump) I have decided to fit underfloor heating to the whole ground floor.  However, in view of the difficulty obtaining tight bends with the usual 15mm PE-X pipe, I feel that I won't be able to get sufficient pipework density to provide the heat emission needed for comfort. The presence of the staircase also means that much of the heat emitted by the 900 x 900 floor area will escape up the stairs so I feel that I need a higher the usual heat output from this small area.

To overcome these problems, I am considering the possibility of using 10mm copper tube for this part of the installation because of the easier bending characteristics, with a view to placing the coils about 50mm apart (or closer if necessary because of reduced water content).  It will be easy to make connections to the rest of the system under the stairs and I'm assuming that I would need to use tube that is PVC coated for protection from the screed.

It seems like a suitable solution to me but before I reach that stage I'd appreciate the views of anyone who's tried it or has a better suggestion.

Thanks.
Alan

Is the house well insulated? UFH doesn't work great in badly insulated houses.

Quote:


Underfloor heating with a heat pump is the ideal installation, but you'll need a second heat supply at least for the hot water purge cycle.

Thanks again.

thescruff wrote on Jun 11^th, 2011, 12:44pm:


The second heat supply will be an immersion heater which I understand is controlled by the heat pump control unit and only used when necessary.


CWatters wrote on Jun 11^th, 2011, 11:02pm:


Thanks for the link.

The property is rural so, unfortunately, there is no mains gas available and most households in the village use oil.  The original plan was to use oil like everyone else but as I'm only replacing storage heaters and therefore have no existing commitment to anything other than an electricity supply, there seemed little point in committing to a fuel that is rocketing in price, has to be bought in advance, needs storage space and is prone to theft.

Although the cost of electricity is higher than gas, I plan to use the Economy 10 tariff (Southern Electric) which I believe will make the running costs very comparable with gas and perhaps a little better.

Be carefull with PV the government have announced a fundamental  review, expect robbing the poor to subsidise the rich to be cut considerably.

With any luck.

As said, if you send a floor plan to the manufactures they will return a drawing.

You could for example.

Have the manifold in that area so all the loops run through the hall.

You could use a larger pipe.

You could install the snail pattern instead of the usual up and down.

Come in from the manifold on the outside, go round and round the room, till you form a loop in the middle then run between the loops back the opposite way to the manifold.