SteamyTea

I think, actually know, that if you fitted UFH with less than 120mm of phenolic insulation, your heating costs would be high. It is still worth insulting the floor as much as you can, it is a large area of heat losses. Large radiators, if the layout is suitable, can be run at low temperature. Placing them on internal walls if possible, or you just get the same thermal problems as UFH. If you are cladding the exterior, have you checked you can do it safely. What are you doing about airtightness? And the associated ventilation and heat recovery.

Telly rots the brain. Why I use a small, portable, radio.

Oh yes. But it makes it easy to convert. I am not sure how good 30W/m² is. It sounds low. My heating season is around 100 days, and I use an extra 1,500 kWh. So 30 kWh/m². Divide by 2400 hours, 12.5 W/m². Under half yours. But it is much warmer where I am. Probably no lower that 8⁰C most of the time. Had 2 frosts last year. Last year my total energy usage worked out at 7.3 W/m². I am sure solar could provide all of that.

It takes around 2.2 MJ to raise a m³ of concrete. So if 0.1m thick, 0.22 MJ. A 1 kW heater, delivers 3.6 MJ an hour. So an hours runner and it has gone up 16⁰C. Assuming half of that goes into the room i.e 500 W, the column of air above it needs 3.1 kJ to raise up 1⁰C (2.5 m ceiling). The air will heat up by 1.7⁰C, but the slab will only be raised 8⁰C. This will obviously change depending on starting conditions, but assuming that the slab starts at 10⁰ C below room temperature, after an hour a greater proportion of energy is heating the air. Personally I think if a room can significantly change temperature i.e. 4⁰C in 3 hours, there really is not a problem.

Can you get more insulation in and end up with the same floor levels?

If you claim for a total write off for a car, you never, ever, accept the first offer. Jenny Tong got the electrical rules changed after her daughter was killed by incorrect wiring.

My old partner, who is no longer around, asked me to 'sort out the satellite dish wires'. I got a shock off the coax, put a meter on it and it read 80V. Events over took me, so never got to the bottom of it.

Isn't that what @DamonHD was working on? https://www.earth.org.uk/open-source-programmable-thermostatic-radiator-valve.html

Yes. Probably sensible to do that anyway. Sooner or later someone will come along with a drill. Could run it as low voltage, but why bother, just more 'things' to buy.

We do have a member that works for an ICF company in the West Country. Just noticed they have replied already.

That will spur them into action.

No idea to be honest. Best send them an email and ask. It may well be that there are restrictions in the small print that invalidates the warrantee/guarantee. As a sanity check, worth asking yourself if they would sell them in the UK if they could not perform within the expected temperatures.

https://www.sunsynk.org/lithium-batteries Shows a charging min temp of 0⁰C and a non derating discharge temp of -20⁰C.

Why not just run some T&E when installing the CAT cables. Costs 40p/m from Screwfix.

Makes me wonder if a customer made GRP roof is possible at £75/m².

Can be terminal for a horse. http://news.bbc.co.uk/sport1/hi/other_sports/horse_racing/9400599.stm

Do you know the performance hit for cold batteries. It may not be worth the bother. Below is the minimum temperature distribution for Heathrow, which is close to you. 0°C and below accounts for 6% of the total time, but remember that it will not be a contiguous string of time.

My sister wanted to set up something similar at my Mother's house. Mother said 'No', well she did after about an hour of stumbling over her words. It is hopeless to decide as the services can be withdrawn at any time.

Is that why it is on Daily Motion. https://www.dailymotion.com/video/x3c8ijh

Jeremy, like me, had a full head of hair. Most on here are old and bald.

Serious question. Do we know how my concrete?

@Galileo While I understand your thinking about new modules and mono v poly in low light. I doubt there is enough difference to worry about. The main thing is what size inverters you can actually buy, they are not sold in 100W increments, usually in approximately 500W increments on the small ones and the 1kW jumps. The main thing that matters is that there is enough voltage for the inverter to start working, so the more modules in series the better. But then even small shading can hurt the output. If it is all too confusing to work out, then microinverters, 1 module, 1 inverter.

An underground wank

Or not.

Good, hope it turns up quickly. Says 'out of stock' so that is a good sign.