Pipe Centres And Other Queries

[Toppers]

I've read/heard conflicting info so I thought I'd ask the questions on here, I'm planning on fitting a wet UFH system between joists on a suspended floor so in one room only (approx 23m2):

 

1. What do the pipes need to be centred at
2. Do I need a manifold or can it be connected using a TRV
3. Does it need to be connected directly to the boiler

 

[Alexphd1]

1. What heat output do you require, what distance are your joists apart? 

2. You need to control the temperature of the water in the loop so you normally use a manifold with a temperture mixer valve but you do get single room mixer kits. 

3. You can connect directly to boiler but high chance boiler will short cycle esp on a single zon, a decent heating engineer will best advise when they see existing set up.

[ProDave]

On that size room, I have 2 pipe loops, so would be using a 2 port manifold.

[Toppers]

18 hours ago, ProDave said:

On that size room, I have 2 pipe loops, so would be using a 2 port manifold.

 

Would the manifold need connecting directly back to the boiler?

[ProDave]

1 hour ago, Toppers said:

 

Would the manifold need connecting directly back to the boiler?

It needs connecting to the flow and return.  I think others have already mentioned the potential for short cycling of the boiler if that is all that is demanding heat.

[Toppers]

Just now, ProDave said:

It needs connecting to the flow and return.  I think others have already mentioned the potential for short cycling of the boiler if that is all that is demanding heat.

 

I'm relocating a radiator in an adjacent room, pipework runs under the floor could that be utilised?

[ProDave]

Just now, Toppers said:

 

I'm relocating a radiator in an adjacent room, pipework runs under the floor could that be utilised?

I don't see why not, depends what valves feed that radiator?

[PeterW]

58 minutes ago, Toppers said:

 

I'm relocating a radiator in an adjacent room, pipework runs under the floor could that be utilised?

 

Only if you want the floor to only be on at the same time as the rads

 

Do all your other rads have TMVs on them..??

[Toppers]

10 minutes ago, PeterW said:

 

Only if you want the floor to only be on at the same time as the rads

 

Do all your other rads have TMVs on them..??

 

I'm ok with the floor and rads being on at the same time.

 

Only one rad upstairs has a TMV at the moment.

[PeterW]

I would (while you've got it all drained) add TMVs to most of the other rooms, the alternative being zone valves and supplies to different sources with linked controls.

 

If you want radiator levels of heat input then 100mm centres will be needed.