Underfloor heating system

[elhughesio]

Hi there,

I really need some advice. To set the scene

3 storey house, 2 of which are in-between joist screed and the other screed slab. Each floor will have its own manifolds and each zone a heatmiser neo thermostat. The house is highly insulated.

I am going to buy a Viessmann 200 vitalness boiler and want to run weather compensation a few questions!

1. I presume that as the boiler varies the temperature, of the water I wouldn't have a temperature mixer on the manifolds?
2. I want to run MLCP to the UFH manifolds. What size pipe shall I use?
3. I'm worried that on the in-between joist floors the flooring is too thick (18mm plywood and engineered wood on top). Will this kill the efficiency?

Any thoughts would be greatly appreciated and or comments to get the most efficient UFH system possible.

Thanks.

 

[snowhead]

1. I presume that as the boiler varies the temperature, of the water I wouldn't have a temperature mixer on the manifolds?

2. I want to run MLCP to the UFH manifolds. What size pipe shall I use?

3. I'm worried that on the in-between joist floors the flooring is too thick (18mm plywood and engineered wood on top). Will this kill the efficiency?

1.You still need a mixer, the boiler can get the water to a higher temperature than the floor can take.

2. That's dependent on the heat loading of the floor,
eg if the floor is 6kw you need a pipe capable of supplying that over the distance from the boiler.
If it's 20kw the pipe will need to be larger

3 U/Floor heat will pass through at least 4" of concrete.

 

[erj]

You will need temperature mixers on each manifold.
MLCP do not know what that is.
18 ply and wood on top a lot might take a long time to warm up check with the UFh system heat makers for advise

 

[snowhead]

https://www.uponor.co.uk/solutions/tapwater-connection/press-system.aspx

Multi Layer pipe

 

[AMW]

If you are using the weather compensater on a Viessmann boiler you need to use the four pipe system on the system boiler version as it will not work properly so bare that in mind when it's comes to 1st fixing.

 

[Chalked]

Have you had the ufh designed? If you gave they will give a kW rating needed. Thus along with pipe distance will give you a suitable size of pipe.

You could get away without mixng valves on each manifold and rely on the weather compensation to control temp, but as the boiler " could" go higher, best to fit individual mixing valves to each manifold and let the boiler take care of itself.

As for the floor covering. Timber is a very good insulator, it has no thermal mass and suffers with expansion. The best covering is fermacell, it is a solid board that is stable, conducts and absorbs heat, and you can tile straight onto it.

Jupiter Systems - Fermacell