Conservatory Heating - more thoughts...

[Mungo]

Hi Folks, About 3 weeks ago I first aired my concerns here regarding the choice of heating for my new conservatory. I've had more thoughts, and whilst not wishing to try the patience of the kind folks here, it's worth my while to see what others think of these new ideas.

Some years ago I refurbished a small bathroom (9 feet by 4 feet floor area) and renewed the chipboard floor at the same time. Before fixing the new flooring, I strapped the sides of the joists with small supporting timber to hold the solid polystyrene insulation blocks I planned on using below the floor. Since one long end of the bathroom adjoined the eaves, I cut some lengths of 8mm or

10mm microbore and made U shaped loops (about 5 feet tall) and laid these one per polystyrene board on top of the board. The poly boards were fitted flush with the top of the joists. Add a 10mm microbore pipe and then screw down the chipboard and the "crush" keeps the microbore in touch with the chipboard. I connected a manifold in the eaves to the heating circuit (come Autumn) and waited to see if the family noticed the "underfloor heating". Though not roasting, the heating effect is pretty good at taking the chill off the tiles in the winter.

So, you can probably now guess where I am going with this...

The present thought is to install wall radiators in the conservatory plumbed via a zone valve to the central heating system. The zone valve being timer operated via one of those immersion-heater timer devices that have a maximum delay of a few hours.

At the same time, install my proprietary underfloor heating but plumb this permanently off the central heating system.

Thus under normal circumstances the underfloor heating ought to keep the conservatory comfortably above freezing, but when you need it you can kick into life the wall radiators.

Any thoughts on my scheme ?

Thanks in advance

Mungo

[Andy Hall]

Quite reasonable. UFH with a concrete floor is relatively slow to react because of the heat capacity of the concrete. However, if you adjust it seasonally it should be reasonable.

There does need to be an additional zone for the UFH to comply with building regulations, because you need to be able to show that it can be turned off.

[meow2222]

I'm told the CH water temp in the UFH would crack conrete or warp wood though.

NT

[Mungo]

Ta for the feedback. I didn't make it clear in the original post, but the conservatory will have a timber floor and not solid concrete.

Mungo

[Andy Hall]

Mmm. Good point. There should be some kind of UFH blending device to reduce the temperature.

[Mungo]

Care to elaborate Andy (yeah, I know I should Google for "blending" but tis the season of goodwill :-)

Mungo

[Andy Hall]

I see.

A Google on { under floor heating conservatory } would work

The point, as was mentioned, is to reduce the water temperature going into the floor tubes. Normally this is done using a blending valve plus a pump. The principle is to mix some of the return water from the UFH circuit with the flow water coming from the boiler so that you have a lower temperature flow into the UFH circuit.

You can buy complete packs for this.

e.g.

noticed that there is a complete installation manual on their site which has blow by blow details of what's involved.

Hepworth also do a pack with a much simpler idea - basically a valve which operates based on return water temperature and restricts the flow. Obviously cheaper, but not as accurate and doesn't limit inbound flow temperature - could be an issue with the floor as has been said.

I think that I would probably look at the information in the Nu-heat solution (there are others like this) and then look at sourcing the components elsewhere if it looks less expensive.