Wet underfloor heating

[stevethejoiner]

I wonder if you can help me, I have a house, that has a wet under floor heating system with ground source heat pump. We have UFH on the ground floor, and bedrooms above, but we have just extended into the loft. I want to install wet under floor in our new bathroom in the loft. Being as it is a new build the house is super insulated, so we have never had to run the heat pump at full blast. In fact it has only ever been set on its minimum setting even in the worst of the weather so I am sure the heat pump is more than capable of running one more room. My question is this, is it just a matter of my obtaining another manifold and running new 28mm flow and returns of the existing 28mm flow and returns to the new manifold, and obviously running loops to and from the new manifold. With the GSHP I realise the pipe centres are only at 100 mm apart as the water temperature is lower than a normal gas/oil boiler, thus you have to run more pipework. And there are no zones on the heating system, all the controls are from either the manifolds and one room stat in the hall and an outside temp thermostat on the side of the property. Thanks.

 

[Agile]

What you have said is that you want to fit UFH just in a bathroom in the loft.

In that case you could probably manage with just 15mm connected to spare outlets on an existing manifold if there is one.

I dont see you need any new manifold either. They are only a way to connect and balance several loops.

BUT all UFH installations are best advised and specced by a pro as there may be some aspects you have not described to us. ( I already wonder how the rest of the loft is heated! )

Tony

 

[stevethejoiner]

Thank you Tony, the existing manifolds, one on ground floor, and one on first floor, are both eight port manifolds and they do not have any existing outlets. So I will have T into the 28mm flow and returns which are accessible in the between the ceiling joists that run to the first floor manifold.
The other room in the loft and the bathroom already have heat leak radiators from two wood-burning appliances, an esse range cooker in kitchen, and wood stove in lounge, so this addational under floor heating for the new bathroom is not really for a heat source, more for underfoot comfort.

 

[stevethejoiner]

Thinking about it, I suppose the fact we have two wood-burning appliances on the ground floor and a heat recovery unit with high spec insulation means the under floor heating and GSHP does not have to work very hard.