MikeSharp01

They do have CIL in Canterbury so do that before you start any building work of any sort.

Yes I think I hope they get to keep it, such drive - the site manager was the best bit, ground worker to project managing a 7m build over night.

Watch today's Grand designs - 2000 sq M 7+ million and we are not at the end of the program yet. It will make your eyes water....

Us too - no issues, quality gear I think.

Your pic shows a rather poor connection between the pipes and the floor above, at least in the bits we can see - air is a reasonable insulator so as things stand you are not getting the heat from the pipe into the floor very well, can you still access it or are you beyond that stage already? Going forward there are perhaps two approaches. Try to stop all flow in the downstairs and then experiment with the upstairs manifold flow rates and the water temperature (+delta T) to see if the upstairs system can be adjusted to cope without the downstairs in circuit. (Keep notes of the present settings so you can return to them at any point.) If it can't then you may need to fall back on making the downstairs do all the work. Do the heat calcs - how much heat you need out of each zone for the length & diameter of pipe, coupling losses, area of the zone etc. Then adjust the flow rate settings in the controller for each zone and see what happens. I get the sense from your original post that the bathroom is your principle concern so maybe just run / play with that loop. Get a gun type thermometer to measure the temperatures everywhere (pipes, floors etc).

Finding pressure drops for components in heating systems can be a pain and while I was looking to do a more detailed analysis of our system prior to install I came across this paper from 2019 that gets well into the weeds of the pex-al-pex pipe and fittings. Well worth a look if you want to understand the details and see the difference a coupler, a union and direct connection. Link is: https://www.e3s-conferences.org/articles/e3sconf/pdf/2019/26/e3sconf_eko-dok2019_00045.pdf

I suspect we need a bit form information / knowledge to help reliably: Is it all coming from 1 manifold or more than 1 (how many)? Do you have multiple pumps in the system or just one? What is controlling the flows is it individual loop actuators or some other?

You will find exporting excess PV difficult if it is not an MCS certified install.

@JamesP & @nod thanks both.

I am just putting the ceilings up where we are using resilient bars and wondered what the best approach would be A or B below. The joints will be tapped but in A are you likely to get movement between the boards? In B you have only a very narrow space to place the screws.

Post a picture or two so we can get an idea what they might be.

Yes I think there is, I am 'in negotiation' now. 22% is a good compromise perhaps and -10 is plenty down here. I think I need to look at the delta T because that has a big effect on the head loss, I just need to keep the interface (between the screed and the wooden floor) temperature below 25 degrees C to meet the guarantee on the floor so its not going to be big if I want 21 deg C room temperature is it.

Many architects and independents offer this service. I chose to take the course, buy the software (excel spreadsheet really) and do it myself, seems to have worked out OK for us.

Coolenergy CE iH6+ and Thermox DTX. My problem is our longest loop at 185m of pipe over 40m2 of floor. I put it in when I expected a solid polished floor and thought the 1.5m head loss would not be a problem but now we are going for a wood floor with a TOG of 1.5 so the picture is very different.

Interesting link! Just got told by our ASHP supplier that Glycol is a requirement of their guarantee! I re-did my flow / heat output calculations and found that 30% of their chosen Glycol will push my pump head requirement up by approx 100% I am now looking seriously at antifreeze valves! We sort of had this discussion back in 2022/23 (and occasionally since.. Not sure we reached any conclusions but the additional pump head requirement does not seem to have been featured very highly in the discussion while the difference in heat transfer does.