Is this design an overkill?

[Romana]

Hello,

 

We have received this heating and zone plan from a renewables company that we would very much like to use for all UFH, ASHP and PV panels + batteries. Our house will be a combo of masonry grund floor (existing) with added external and floor insulation and first story extension + habitable attic space in timber frame.

 

Wet screeded UFH proposed downstairs, "wood 22 system" proposed for upstairs.

Quote

The system will comprise of 22mm routed chipboard panels supplied by Terra Therma Ltd and fitted by others directly to joists. Terra Therma will then make any additional cuts/routes on site for the UFH pipework to be laid within the boards. An 18mm support layer of chipboard must be laid beneath any turns cut into the panels. Standard timber flooring systems would comprise of levelled joists or battens installed at a standard width of 400mm between centres. Between these joists or battens should be some form of thermal insulation, either rigid (Celotex) or compressive (Rockwool).

• Output – up to 70W/m2.
• Insulation – Rigid insulation or compressive insulation between joists.
• Board Size – 2400mm x 600mm x 22mm. T&G on all 4 sides.
• Pipework –16mm pipework fixed at 200mm centres.

 

The ground floor quote came to what we were expecting but the upstairs is more than double that per m2 and we would ideally find ways to reduce that. I do like to be warm - I have read some people here leave their bedroom at 18 degrees. I WOULD DIE. We also have two toddlers so they spend a lot of time playing in their rooms and need them to be warm enough for small children.

 

Here are the diagrams of proposed heating zones. Does anyone have suggestions on whether these could be simplified in order to bring that first story cost a little bit down? No UFH planned for the attic space.

 

Thank you!

 

[JohnMo]

For me we have UFH in bedrooms and as soon as you add carpet it becomes rubbish. I would use fan coils in bedrooms, you get responsive heating and good cooling in the summer. You would just run the same flow temp as the UFH and the fan coil control would do the rest. You can also use the bathrooms. Seems expensive at first. Here is a selection (many different makes available)

https://coolenergyshop.com/collections/radiators-fan-coils

 

Ditch the UFH in bedrooms.

 

One of the issues with wet rooms and UFH is the proportion of floor space taken by baths and showers and fitted furniture, so is never the most effective, unless you go really tight pipe spacings. So in bathrooms add wet UFH if you want, but you need to add a heated towel rail also, you can these so they operate on water and have an immersion inside to boost output when needed. You could look at IR panel heating in bathrooms? Or fan coils again

[Pocster]

My view and experience is the opposite .

We have ufh in the bathroom . I was worried it wouldn’t be enough to hear the space so added an electric towel rail .

Towel rail has never been put on . Ufh in the bathroom ( as such a relatively small room ) heats from ufh no issue .

I have ufh in bedrooms . Because someone ( I.e SWMBO ) will always want it warmer !

[JoeBano]

First winter with fan coils in my bedroom they are fantastic. I can get upstairs to 23c with the same flow temperature as my Ufh heating downstairs. Then summer comes I can keep my bedrooms nice and cool. The negative is the price of fan coil units, mine was supposed to be £900 a unit, I got a steal of eBay. I do have Ufh in my bathroom which does well but also have a electric radiator come on twice a day for towels 

[Alan Ambrose]

>>> The ground floor quote came to what we were expecting but the upstairs is more than double that per m2

 

Ask them why? Is it the special chipboard? There are other systems. I think if you’re getting a lump sum quote for a bunch of stuff, drilling down into the detail is usually worthwhile. Have you got competitive quotes?

[Romana]

On 21/11/2024 at 11:54, JoeBano said:

First winter with fan coils in my bedroom they are fantastic. I can get upstairs to 23c with the same flow temperature as my Ufh heating downstairs. Then summer comes I can keep my bedrooms nice and cool. The negative is the price of fan coil units, mine was supposed to be £900 a unit, I got a steal of eBay. I do have Ufh in my bathroom which does well but also have a electric radiator come on twice a day for towels 

Thank you for your response. Is the fan coil system even more complex than UFH? Does it not take up the ceiling height for the duct system? It does sound fantastic, being able to use it for both heating and cooling.

[Romana]

On 22/11/2024 at 08:00, Alan Ambrose said:

>>> The ground floor quote came to what we were expecting but the upstairs is more than double that per m2

 

Ask them why? Is it the special chipboard? There are other systems. I think if you’re getting a lump sum quote for a bunch of stuff, drilling down into the detail is usually worthwhile. Have you got competitive quotes?

Why is a good question - to me it sound like the answer lies in the "Terra Therma" using their own chip boards and coming to do the cuts themselves - my guess would be there's a level of main contractor charging for sub contractors, both of which will add profit margins to their quotes.

[JohnMo]

4 hours ago, Romana said:

Is the fan coil system even more complex than UFH? Does it not take up the ceiling height for the duct system?

Some photos of mine, left hand side are an inlet and out water connection. The controller is on the right hand side. Bottom image is the cover on

 

[Romana]

2 hours ago, JohnMo said:

Some photos of mine, left hand side are an inlet and out water connection. The controller is on the right hand side. Bottom image is the cover on

 

 

I see, definitely food for thought. Thanks for sharing!