Underfloor heating or what?

[Richard A Downing]

We're in our sixth month in a new house in Cumbria, having moved here from warmer climes down south. The house is a 1970-built bungalow with solid concrete floors and cavity walls. The heating system doesn't keep the house warn enough, so I am having double glazing and cavity wall insulation fitted in the new year - the loft space is already 200mm insulated. The double glazing is most important here as the design of the house has 2.5x1.5 metre windows - to show off the views. However....

The Sitting Room is 4x5.5m with a 2.5m ceiling - a big space. One

5.5m wall and half of another are glass (soon to be double glazed 28mm) making this a difficult area to heat. There is easily 85mm of available depth from the lowest cill to the current floor.

I'm thinking of putting in an insulation layer with PEX pipe and a screen to take up the available depth and provide Underfloor Heating. Does this sound feasible? Any ideas on cost or recommended suppliers?

R.

[Christian McArdle]

Yes, this would work. However, due to the high heat loss from the windows, you might want to maintain some additional space heating (i.e. radiators). These will heat the space much quicker from cold (underfloor takes ages to get into its stride) and will enable the system to maintain temperature even in cold weather. The controls should be carefully designed so that the floor stays warm until temp is reached and the additional space heating only comes on when required.

Christian.

[Set Square]

If you can afford to raise the floor level, why not use a layer of rigid foam with a wooden floor on the top? By the time you've double glazed, and insulated the cavity walls, the existing heating system will probably be adequate.

[PeTe33]

I can wholeheartedly recommend UFH esp. where wall space for big ugly radiators is limited. It also makes hard (wood/laminate etc) floors a delight to walk on un-shod.

We had approx 45M sq. in 4 zones planned and supplied by Nu-Heat

CAD drawings and tech. support was superb for a DIY install.

Cavity wall foam has made a massive difference to our house, temps now come up pretty quickly, Also added blinds (both vertical & roman) to all windows (previously un-curtained) which has made a great diffeence.

The only problem we have now, is down to our currently un-insulated loft which seems to draw away significant amount of heat when there is a stiff breeze blowing; it's actually colder inside with an outside temp of 7 or 8 degrees with wind blowing than it is on a -2 degree still night with no wind.

One other thought...... your dooways will all need specially sized doors unless you raise the height of the doorways.

Draughts(sp) are a big issue, I am presuming it is quite windy where you live. Definately go for UFH though.

:¬)

[PeTe33]

And don't forget to have a small "regular" heating zone to supply a towel rad. or 2 in your bathroom & on-suite etc.

[The Natural Philosopher]

Yup. have a look at polyplumbs site foir all the bits and pieces.

I went in at 50W/sq emeter acording to their calcs,..with decent insulation its enough, though warm up times are fairly long - typically over an hour really.

If its just the one area use a radio stat to get it adjustable - you need a temp reducer and separate pump and a relay as well to drive the UFH PROPERLY though you coiuld work a bodge on the cold return side of the radiator loops if you wanted. Its NOT good to put 60C water under screeds...cracks em.

If at all possible put it everyweher, with zone stats and motorised valves on the manifolds. It is witout doubt a great way to heat a place.

[The Natural Philosopher]

If you do put in rads as well, put them on a different zone, yes...but there is no requirement to have ANY rads if you don't want.

Or even an overall stat - you can run each room as a separate zone, off a master manifold and pump..

And wire OR the motorised valves together to control the two pumps.

[PeTe33]

I would disagree. A heated towel rail will effectively dry wet/damp towels without having to leave them spread all over the floor and if fully toweled, not produce much heat output to the room, but can be un-covered in really chilly times.

.. though I did come home one day to find the whole of the lounge floor covered in neatly spread "out of the washing machine" clothes !

That's what we have, though in an open-plan situation there is never a great variation between zones.