What to put where & what to allocate for the future ? UFH

[syne]

In my eagerness to get to dpc/slab level I've neglected to increase my knowledge of how heat pumps work with UFH and what exactly I'll need to do to accommodate these in the future.  I'm meant to be pouring the slab next week!

Apologies for the spoon-feeding request, obviously I'm off on a mad google search shortly.

 

/

 

 

The library/Entrance  -4mx6m-  is going to have 200mm insulation with a 150mm concrete slab.

The existing lounge and kitchen (shaded blue) will be dug out and UFH put in later, so I want to prepare for that now.

 

1. How deep into the concrete below ffl should the ufh be set?    I was thinking 50mm

2. What pipe should I use?

3. Do I need a manifold now, 5 zones. any recommendations?

3. How much pipe should I leave proud of the concrete? 60cm?

    (internal garage door is not being built in, internal wc not being built either)

5. Will it be okay run 6 pipes for the future existing house ufh and just cap them off in the kitchen like red/blue lines below?

     even though it's going to be approx. 15mths before the rest of the ufh is built in.

6. what method should I use when passing ufh pipe under walls? 

 

7. What don't I know that I really need to know before I cock it up?

 

 

 

[Mr Punter]

I sent plans to Wunda and they gave me a price the next day.  They will also do a design for you if you want to go ahead.

 

If you are heating up 150mm of concrete it will take an age.

[Redoctober]

Oh dear ! - I am trying to understand your current situation from the above, so please excuse me if I am missing something. 

 

Have you any UFH pipework down across the ground floor? If so, then why not follow what already has been done? 

 

If not, then perhaps try to secure an UFH plan ahead of the screed being poured because surely, once that is poured your oppurtinty to have UFH has been missed, unless you go for an electric system. By securing such a plan, a lot of your questions should be answered therein.

 

Can the pouring of the screed be delayed ?

 

 

[JohnMo]

A little confused, why is the UFH manifold looking like it's in the garage?

 

Assuming the 150mm slab is reinforced, if so attach the UFH heating pipes to the reinforcing mesh. Do the pipe in 16mm pert-al-pert pipe. Centres really depend on the overall W/m2 you need to generate, do you know?

 

Ivar are quite good manifolds etc.

 

You really don't want to be planning for joints in the concrete!

 

Can you not take pipe through doorways?

[Iceverge]

I assume this is a renovation? What kind of heat loss figured do you have for the remainder of the house?  

 

UFH pipes widely spaced in 150mm concrete and heat pumps may not be the best choice as it's very slow to react and only works as a "banked heat" in very well insulated houses.

 

If you have a poorly insulated house a quick reaction system would be preferable.

 

IE very large radiators or high output (closely spaced pipes) UFH in a thin screed. 

[syne]

OK thanks for the replies, in answer to some of the questions..

 

Im building an extension, the green loops are very rough examples of  what/where i need to put ufh in the slab.

The extension is to be quite well insulated;200mm under floor, 150 in walls and 200+ in roof.

Similar levels of insulation in exsiting house, no ufh in the existing house currently and I can't rip the floor out till much later.

 

 The manifold is in the garage,as that's where the ashp/cylinder "plant room" will be. 

Garage is also insulated to 100mm.

 

W/m2 I need to generate ? No idea yet. Also no heat loss calcs, yet.

 

No reinforcement in slab specified, but can still be added should it be needed, so I can set height of ufh to whatever is most appropriate. 

 

Looks like I need to have a more definate plan before I can proceed..