JohnMo

Didn't think smart meters used phone signal, thought they used there own long wave system?

To us, but just BC to keep happy now, but wouldn't do anything until you see something in writing from them

How do you keep them dry in a damp space, they will be be all swollen up in 6 months. Plasterboard over the top?

It may be the roads people

You need to look at your local regs, our, when on a single track road you have to form almost a layby so delivery vans etc. can stop without blocking the road. You would have to look at that and see if what you propose is practical.

Your outside tap is connected to main water, and you get 20l/m, ideally you could also do with pressure measurement on the main to compare the pressure change with no water being run out of the tap and 20L/min coming out of the tap. To compare the dynamic and static pressures. This will give you a known point to start from. Your balloon is the water main in the street, the straw is the pipe from the water main in the street to the house. That is the first point to test, to see what happens. The mains water pressure at peak times should be a minimum of 1.5 bar dynamic pressure - so pressure when your outside tap is fully open. If its lower than this you will have flow issues, no matter what pipe you use and it is mains supply rate / pressure that is the issue. Start there to confirm all is ok at the inlet end.

Where are you measuring this? Has the issue always been the same? Most likely nothing to do with the pipe used. Upstream or down stream of the cylinder. My UVC is piped in 22mm Hep2O upstream of the UVC and then in 16mm pert-al-pert pipe with a 14mm bore or less, pipe run at longest is 20m and have zero flow issues. When you enter the tap the bore size will drop to around 6 to 8mm, they will also have built in flow restrictions to limit flow rate also. Your straw analogy - water velocity would simply increase and then return to normal after the restriction. The restriction would rob a very small small amount of pressure head.

Or Following this https://www.pandhengineering.co.uk/advice/pressure-loss And use this data sheet for MCL pipe and fittings Uponor-s-press-plus-technical-data-sheet.pdf

Not a plumber but easy enough. 1. Calculate pipe pressure drop, plenty of online tools for that. Just use the internal dia. and length. Internal dia isn't going to much different from 22mm Hep2O so you could use that as a reference. 2. Basically do the same again for the fitting at each end, but obviously a much shorter length. 3. Add the results together, covert meters of head loss. You will be surprised how little the small bore fittings make.

Our became a posh shed. Double bedrooms stripped out - shelving added etc.

Good insulation and 100mm plus of concrete in the floor can make energy use and storage can easy task - but you have to embrace it. I currently have next to no need to heat the house, but the garden room still needs heat, so just use the floor of the house as a buffer. Heat pump puts out 30 Deg water for 15 to 20 an hour to garden room fan coil, house UFH runs at the same time. It's cheap, it's there, zero additional plumbing no energy goes to waste. Currently should be getting CoP of 4+, so between E7 and battery the heat energy is being produced at 4p (or less) per kWh.

Another consideration if you went this route would be choice of heat pump. Nothing complex is required as you would operate on a fixed flow temp from the heat pump, it wouldn't need modulation either. So a cheaper model would be fine. Maybe save £2k on heat pump, spent £1k on big thermal store and mixing valve.

Is there a weather compensation curve set?

Your post is long and a little confused, can you say in a couple of simple sentences what you want to connect, what has pump and what doesn't Defrost, doesn't really care if there are loads of pumps or no pumps, as they will be on if you need to defrost, so it will just take it needs from the return water. Heat pumps are just a heat source. The plumbing is the same really. You have asses dT and with that the required flow rate, to get the kW output needed. Then make sure your pump can handle the volumetric flow at that head loss. UFH loops are parallel loops, so the pressure drop on a manifold is the longest loop length only. Multiple manifolds in different floor buildups are likely to have different flow temp requirements, if these are minor you can adjust the flow rates to balance the system, but most likely you will need mixers and pumps. The offsetting function is really for radiators, could lead over and undershoot of room temp with UFH so be careful. But as stated sit down and work it all out, or rather the MCs contractor is obliged to do this prior to starting work.

a) depends on shading and even then you can just fit optimisers. I like a single inverter. More the better for kW. Winter can be rubbish, no matter how much you have.

3x2 stud wall, with 12.5mm plasterboard each side, 95mm thick. 50mm high sound insulation.

I would leave it on - why faff about over a few pence a day.

Here is what I did If you can buy a kit, mine is 70mm thick timber and fully insulated top bottom and sides. Way easier and not that expensive for what you get

Your missing something Be careful with Jeremy spreadsheet as it's only really works well with just about airtight and very well insulated. Your downwards heat loss is ground temp and means UFH flow temperature - not room temperature. Rubbish insulation means high mean flow temperature, your mean temp could be around 30 to 40 degrees, so 4 to 5kW downwards or 100kWh a day. Rethink - Everyone mentions 150mm min for good reason.

Mine is in plant room. GivEnergy all in one - MCS install.

Concrete or postcrete, mix it well as you add to make sure no water pockets. Level just about ground and slope top away from post so any water naturally runs away.

Again do your research, any heat pump (almost) will perform well if system design and operating philosophy is good.

Fire and fire risk really depends on technology used for the battery. 1st write-up I found https://www.fogstar.co.uk/blogs/fogstar-blog/how-safe-are-lifepo4-batteries

Running at a higher flow temp just for that is bonkers. Just make them electric, TEMA do various output immersion to screw in to rowel rads and external thermostat for programming. Ok the control of an external pump then would still be controlled by the heat pump. If you dump the water heated rads, no need for mixer or additional UFH pump. You just need to control zone valves.

If you are well insulated I would put provisions in for electric panel heaters in bedrooms, many on here have no rads or heating on bedrooms. Upstairs bathrooms will need heat. Electric towel rail is good, would also look at electric UFH directly under the tiles.