Manifolds for UFH - inside or outside home?

[Deansplit]

Should these go inside my kitchen in a cupboard of outside in a boiler house - this may be single block so would this mean it would need to be a cavity walled boiler house to stop them losing too much heat?

 

[Boilerman2]

It would be a lot easier if they were in the kitchen - the point of the manifold is to divide a single flow & Return into several separate circuits, (loops), it would be possible to put this in your Boiler house, but NOT PRACTICAL so go for the Kitchen cupboard -it would be at the back and wouldn't take up too much room

 

[Deansplit]

How accurate does the position of the pipes need to be as the kitchen units won't be in at the time of installing the UFH. Is it a case of getting them as close to possible to where they are going to be mounted?

 

[mointainwalker]

How accurate does the position of the pipes need to be

Do you mean in relation to the manifold ?

Each pipe needs to be vertical coming up from the floor to its assigned connector, so don't cut them too short. If it's 16 mm pipe off a reel, it's going to try hard to twist away, so you need to be well-positioned to start with to feed straight onto the "neck" , avoid cross-threading and leaks.

 

[Deansplit]

Yes, meant in relation to manifolds. So are they fixed to the back of the cupboards, or do they have to be against the wall itself?

 

[Agile]

Its not clear if you are thinking of this as a new project.

In that case I would say put the manifold in the boiler house if attached to the house and make it insulated.

I have a vision of you hiding a manifold behind kitchen cupboards where its inaccessible.

Its far easier to fit the manifold when the pipes are laid as long as you can protect it from damage when laying concrete over the pipes if thats the plan.

Tony

 

[Deansplit]

Oh, you're saying fit in the boiler house - I was just convinced to put in the kitchen due to hat loss outside. It's basically a 10x4.5m space and the boiler house is attached to the short edge (on the out side obviously). The company providing the system do a CAD drawing so they need to know where I want to put the manifolds. They also said it's better if they're situated centrally to the room rather than one end - the boiler house option would be the latter.

Mmmm, confused now.

 

[Agile]

The simple answer it can go anywhere!

For maintenance it should always be accessible. If thats only going to be possible in the boiler room then put it there.

You seem to be planning not to use insulated construction for your boiler room.

Even if you must have a single skin walls its easy to put 50mm insulation all round the room to insulate it.

Doesn't your installer have a view to answer your query?

Tony

 

[mointainwalker]

Ideally the manifold should be sited centrally as this makes planning the layout much easier and more efficient for other reasons.


If you drag it/them out to an extremity like your boiler-room...:

1) You are much more likely to get significant difference in circuit lengths,
which is not good.
2) You will find it difficult to avoid pipes crossing over each other which is not good.

3) If you have three or four 16 mm pipes coming in from the the boiler-room, they are going to be losing more heat than one 20 mm feed to the manifold inside.

4) You'll use more pipe which costs more money.

 

[Deansplit]

Haven't appointed one yet, it'll be a while before the boiler house is even built, and the UFH people need to know asap to commence the CADs. Someone else mentioned 50mm insulation - do u mean directly against the blocks or slightly away on battens (ie. if in direct contact to blocks, will it be prone to damp?)

 

[Agile]

Assuming you use the insulation boards with a reflective membrane then the usual advice is to have a small air gap to reduce the chance of condensation. However, thats based on condensation from the inside possibly forming on the wall.

In a boiler room that seems less important.

I would use a cavity construction as its adjoining the house.

Tony

 

[Deansplit]

I have some Kingspan mounted to plasterboard - been itching to make a use of it!! Would it do? Think it's 35mm tho.

 

[Agile]

If you have got it then use it.

But you dont really need plasterboard on the inside and 35mm is not as good as 50mm.

Not quite so bad if you had an air gap from the wall though.

Tony

 

[ianniann]

The reflective surface on insulation is a radiant barrier. It should always be fitted facing a small air gap or there is no barrier and the reflective coating is a waste of time and money.

All insulation boards, even in cavity walls, are recommended to be fitted with a small air gap. This is not simply to prevent condensation, but also so that any water ingress through cracks in the mortar doesn't get trapped. It is only critical in certain locations, but is good practice anywhere.

 

[Deansplit]

I think it's 50mm incl the plasterboard (not that pb has any heat retention!). It's really just that I have probably the exact amount for the area required - it's been sitting in my garage for 5 yrs so would be good to make use of it!