underfloor heating temperature difference

[Fenning]

hey folks,

Can anyone tell me what is the expected temp' difference
between the flow and return in an underfloor system.

The loop length is about 89m.

Thanks in advance.

 

[Fluffster]

So many variables
How close are the loops
Is the pipe insulated to the room
What is the floor construction
What is the heat loss in that room
Pump speed

The temp diff will be all over the place on heat up, set back and constant.

On a 89m run I am guessing you have the flow meter open almost fully.

Are you having any particular probs with the ufh
Pete

 

[Agile]

That seems like a very long loop!

Even with a maximum pump heat you will probably have an unecessarily high differential.

I would suggest about 10°C might be typical but I encounter a very wide variation.

Tony

 

[Fenning]

Sorry guys for not getting back sooner but I've been away.

Anyway this is a new installation (the floors aren't down yet) and I was just wondering about this for the comissioning.

There are 11 zones and some of the zones have 2 loops of 80(ish) m. The tails are all insulated, the floor is screed and the loops are a minimum of 200mm apart. I dare say the pump speed will be set at the comissioning stage.

I expect a 10 degree difference between the manifolds would but reasonable then.

Thanks again.

 

[LMannix]

Sorry guys for not getting back sooner but I've been away.

Anyway this is a new installation (the floors aren't down yet) and I was just wondering about this for the comissioning.

There are 11 zones and some of the zones have 2 loops of 80(ish) m. The tails are all insulated, the floor is screed and the loops are a minimum of 200mm apart. I dare say the pump speed will be set at the comissioning stage.

I expect a 10 degree difference between the manifolds would but reasonable then.

Thanks again.

Is it a John Guest Speed fit system? If so give them a call, they do surveys, commissioning etc all for free. If you have any problems its best to sort them now before the screed goes in.