@judith I have signed up for Heat Punk but it doesn't seem to have anyway to create  a profile using UFH. Only shows radiators.

Posted by: @mike-camelot

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You need to scroll down for English (sorry that's rather obvious). It would seem that my installer has used option 2

 

Now the link works you are right.  Installer is still wrong though IMHO (workings set out above) to install it as a 2 port buffer not a pure volumiser, unless there is something very strange about your house.  Obviously the tank itself is just a tank and can be used for multiple purposes.

Posted by: @jamespa

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Obviously the tank itself is just a tank and can be used for multiple purposes.

What about a door-stop? 😉 

Mike, do you have a record of the pipe lengths in those UFH loops?
If so, then we can calculate the volume.

I think that's 16mm (outside diameter) PEX, which has a 12mm bore.
Every 22m of pipe holds 1-litre.

@transparent Looks like I have a lot of alterations. I will be speaking to my plumber on Monday.

I have had many discussions with Wunda (UFH) during installation and after. It has become very obvious that the Company is attuned to boiler type heat sources. They could not accept the concept that their system controller was not wired to signal the ASHP pump to run. I felt that eventually there was just a "shrug of the shoulders".

When I realised that the concept of an ASHP supplying UFH, I asked why they had supplied mixer valves? They are still fixed on boiler supply, but they did eventually say they could be removed or turned fully open. Which is the way I already had set them.

Each zone is has 1, 2, or 3 loops that are monitored by an in floor sensor. I have the requested temperature is set to a point so that all the valves will be open. The sensors are set to a maximum temperature limit of 25C (I have KVT flooring). I am definitely not getting balanced flow through the loops. It is becoming very clear that there are multiple reasons for this which I will try to address. 

Air release valves- plumber Monday.

The flow indicators on the supply (top) manifold can also be used to adjust the flow.

Backing board. My lack of experience showing again. There have been many occasions during the build when I would have hoped that contractors with their extensive experience would have bee a bit more forthcoming.

The insulation. Not single pipe was insulated by the ASHP installer.

I have been trying to play catch up, but I have had a lot of other "situations" in the last few months and it has just been a case of priorities.

I really appreciate the time and patience of all those that are trying to set me in the right direction.

Posted by: @mike-camelot

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I have had many discussions with Wunda (UFH) during installation and after. It has become very obvious that the Company is attuned to boiler type heat sources. They could not accept the concept that their system controller was not wired to signal the ASHP pump to run. I felt that eventually there was just a "shrug of the shoulders".

From several reports on this forum it seems that many UFH installers are just that, UFH installers not heating engineers.  They see their own sub-system in isolation, and don't ever consider it as part of a bigger system.  Thus it is obvious to them that it must have a call for heat and thermostats. 

Easily overcome though, just turn all the stats up or disconnect the call for heat from the UFH and wire the two terminals together on the ASHP.  You have already worked this out though!

Posted by: @mike-camelot

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When I realised that the concept of an ASHP supplying UFH, I asked why they had supplied mixer valves? They are still fixed on boiler supply, but they did eventually say they could be removed or turned fully open. Which is the way I already had set them.

Ditto, which of course you have already worked out.

Posted by: @mike-camelot

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The flow indicators on the supply (top) manifold can also be used to adjust the flow.

Which is the way to do it.  Its exactly the same as balancing radiators.  Remember to leave at least one fully open though (probably the longest) so that you aren't unnecessarily restricting flow.

I think its best to regard installations of this kind as a kit of parts and controls, which can be configured in various ways to do what you want.  No particular harm in that except for the unnecessary expense on redundant components.  In the grand scheme of things its probably not much though

@transparent It is actually shown as a 20mm pipe. I assume that is the OD. The ID is probably 16mm?

The installation has 2 manifolds. left has 7 loops totalling 422 metres, and right, 6 loops totalling 526 metres

Posted by: @mike-camelot

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It is actually shown as a 20mm pipe. I assume that is the OD. The ID is probably 16mm?

The installation has 2 manifolds. left has 7 loops totalling 422 metres, and right, 6 loops totalling 526 metres

That increase in diameter makes a huge difference of course.
Assuming a 2mm wall thickness, every 5m of pipe holds 1-litre.

That means the UFH pipework holds 190-litres...
... which begs the question of why any form of buffer or volumiser would be required.

What does @jamespa think?

Mike - do you have a vernier caliper with which you can check that external diameter?

Better still, did they leave an offcut of pipe lying around?

Posted by: @transparent

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... which begs the question of why any form of buffer or volumiser would be required.

What does @jamespa think?

Well I suppose the installer can't know that it will be operated open loop so providing a volumiser with sufficient capacity for a defrost is a safe measure in case defrost coincides with all or all but one zone closed off.  Safe that is unless its plumbed as a buffer.

Posted by: @mike-camelot

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Backing board. My lack of experience showing again. There have been many occasions during the build when I would have hoped that contractors with their extensive experience would have bee a bit more forthcoming.

And were they contractors with experience of self-build concepts I wonder?

As I do all tasks myself I tend to buy the optimal material for the job.
I came across Fermacell at a Building & Renovating Exhibition, where I could see demonstrations of it being used.

Most of my new walls have 12mm Fermacell instead of plasterboard, including my plant room (below).

Here's a photo from this afternoon when I fitted a bracket to hold a (heavy) hybrid inverter.

The silver screws on the right are aligned with a vertical support timber.
The three brass-coloured ones on the left are screwed straight into the Fermacell with no wall-plugs.

Each directly-driven screw can hold a whopping 30kg of vertical weight.
I've once screwed an entire 3-piece suite to the wall with nylon baler-twine so I could tile the floor beneath! 🤔 

Imagine how easy it is to relocate pipes, kitchen cupboards, shelving etc.

@transparent Yes. I have a micrometer. I think I have a piece outside. I will have a look tomorrow.

@transparent My apologies. It stated 20mm Rapid Response on the pipe layout plan. I assumed that was the pipe size. It is actually as you suggested 16mm OD and 12mm ID.

@mike-camelot I thought it did have ufh from memory on one of the later updates. Sorry! BUT at first I used an equivalent radiator from the W/m2 heating from the under floor pipe spacing. Then 

Its a bit of a pain but the more you understand your system in detail the better, then the trade-offs are what you want, not what’s easiest for the trades-people.