JohnMo

Any HSS drill bit will do it, as long as it's a real one, not cheap Chinese ones. The import bit is applying the correct pressure, this doesn't come from a hand drill, unless you are drill small holes. You need coolant also.

I use these on all the extract ducts https://www.epicair.co.uk/products/extract-air-valve-filter-for-8960-125mm-valve-10-pieces

Do you need anything, a thermostat that can do heating or cooling mode, run the flow temp at a fixed 15 degrees - job done. Little or no concern with humidity anywhere and a floor surface temp cool enough to manage house temps. I did a drain down of an UFH loop in the summer and the water coming out was at 25 degrees. So if you flow at or around 15 degrees you should be doing about 10 degs of cooling over the floor area.

Sorry didn't go all the way back to your older post 2020, just read the above. Where you mentioned bills and reducing costs.

We have Durisol, so similar. When I spoke to our building insurance people and said we had built using an ICF block, I asked if that was a novel or standard build, they said standard it's just a reinforced concrete wall. Breaking the construction down, an ICF block is just concrete formwork that remains in place instead of being removed. So your construction is just reinforced concrete that is insulated.

If you are concerned just use ufh pipe (pert-al-pert) and use a 16mm to 15mm adapter at the radiator, you can do it any length you like with that pipe joint free.

Worth a read https://www.bennetts.co.uk/bikesocial/reviews/products/motorcycle-maintenance-and-servicing/best-rust-corrosion-preventer-inhibitor

Why do you need the circulation pump on the return going ASHP 2, the heating manifold pumps will do just fine, pulling from the buffer and returning it. You have 4 pumps, without hydraulic seperation, so you could/will end up with pumps chasing there tails. ASHP 1 and 2 seem huge. If No 2 is just back filling if No 1 doesn't cope.

My VAT claim was delivered to VAT office yesterday, so will see how long it takes to be processed. Only one A4 box file for me.

It was only valid to 01/01/1800. So you're 223 years late to the party.😀

It's a Maxa ASHP, with its own inbuilt controller. The only third party bit is a limit stop thermostat, one in the house and one in the summer house. Just need to finish the install, work and weather keep getting in the way.

If you wanted

CoP would be rubbish most of the time pump 50+deg water around. Think things are being made more complicated than they need to be and would result in something that cost a small fortune to run. Just had a look at my ASHP controller, it can set two flow temps controlled by a open/closed contact, as well as another temp for DHW. But it would only flow either a high or low temp, not both at the same time. It can also control a mixer valve if required. Best CoP and simplest design would come from running UFH and Rads at as low temp as possible (i.e. big radiators).

I have often though about this (sad I know). When you compare thermal properties of PIR, those covered in foil and those not (other materials not aluminium) the not reflective coating PIR, always seems to have a worse figure for thermal conductivity. So does the 0.022 thermal conductivity already make the assumption there will be an air gap? I am assuming so, as the aluminium foil is actually a heat conductor if its a reflective surface.

Yep

I have played with boiler settings quite a bit over the last year or so and found the following. 70 and above, the boiler control will modulate flow rate to achieve a delta of 20. But - as you bring the flow temperature down, the delta T also comes down also, when you have a flow temp in the high 20s to low 30s, the delta T is around 5 or 6, the pump flow rate is automatically adjusted to maintain this. So is working very similar to a heat pump.

That may be difficult

Looks to hitting max kW of 12 ish then it trips?

You will have a max temperature set in the control system, so the boiler slowly increases power and therefore heat output, once it hits the max temperature setting it cuts out. It will continue circulation and when it sees the return temperature drop by a given temperature, it will kick back in to life. This ramping of temperature aids efficiency as the temperature across the heat exchanger stays low for as long as possible promoting condensing as much as possible. Condensing starts at about 56 degrees, the lower the temperature range across the heat exchanger the more condensation the more the efficiency increases. I'm currently at about 120% efficiency consistently for UFH.

Of cause it is, we are not talking cost of a kitchen. If you install something to save on gas as @Levo did (his 3rd motivation), that being MVHR, its running cost is relevant. If it cost £100 to run and maintain and saved £50 in gas consumption, it would be a waste of investment and would fail to achieve his 3rd motivation. In this case, gas saved is greater than electric used and filters, so win win.

What you are seeing is fine, in fact very good.

Good to see, you will find your gas consumption drop considerably. Mine did similar to you first and second graphs, then closer to your final graph, gas consumption dropped by around 30%

You need to take account of running costs (electric) and filters also, for the complete cost saving.

Not completely correct. They actually state NOTE: Installing thermostatic room controls may not be technically feasible in some cases. These may include the following. a. Dwellings with very low heat demand (e.g. less than 10W/m2). b. Dwelling with buffer zones for heat absorption or dissipation with high thermal mass. The regs don't define b. in any details, so thick screed UFH could comply and not require room thermostats 5.21 It may be justified to control a heating zone rather than individual rooms in either of the following cases. a. In single-storey open-plan dwellings in which the living area is greater than 70% of the total floor area. In such cases, the dwelling should be considered as a single heating zone. b. Where two adjacent rooms have a similar function and heating requirements (e.g. kitchen and utility room). In such cases, the adjacent rooms should be considered as a single heating zone.

Confused, what are you saying? I used fibre reinforced concrete, mine was installed before the walls went up.