JohnMo

Meant to include the source of the prices https://www.google.co.uk/amp/s/metro.co.uk/2022/09/10/energy-price-cap-how-much-is-electricity-and-gas-per-kwh-17342836/amp/ Also from Which? If you pay by direct debit: Your rates will be an average of 34p per kWh for electricity with an average standing charge of 46p per day, and an average 10.3p per kWh for gas with an average standing charge of 28p per day. These rates will be slightly different depending on where you are in the country

A resurrection of an old thread. I am in a similar position wanting cooling over summer and no heat pump. The problem is solar gain, and general overheating even with low ambient air temp. UFH water trapped in floor is around 25/26 degree C. Location NE Scotland. Overnight temps generally low to mid teens even in height of summer. My idea 1000l IBC filled with inhibited water, suitable for UFH. Suitable valving to connect to UFH mixer and pump. Use UFH pump to circulate from IBC. Heat from floor slowly transferred to IBC, giving a cooler floor, hopefully a cooler house. Overnight or even during a cool day the secondary pump circulates water through large car radiator and fan to cool IBC to close to ambient. Can run the fan from 12v battery or 2 and simple car charger. I think? I have radiator, fan, battery and charger, can get IBC for £50. Will need circulation pump, valve and pipes. 1000l of water starting temp 18 end temp 25 will absorb around 8kWh. Does this daft, workable or need a bit of work.

Looks good, still looks funny, living in Scotland, where they use sharking boards and no battens unless they are using concrete tiles.

Back to the title of the thread, seen this Under the new government’s EPG scheme, which has frozen energy bills at £2,500, people in England, Scotland and Wales will pay an average 34p per kWh of electricity. Similarly, people England, Scotland and Wales will be paying an average 10.3p per kWh for gas

Think I would consider stick build. There are a few people on here who are way more knowledgeable than me, who have suggested to a few it's the way to go.

So it weather compensation with load compensation. That's why you need to ensure the system is balanced and the curve is right. If your room is overshooting, either flow temperature is too high, or the flow rate in that room is high. You need to set the flow temp to most of the rooms at the correct temp, then tweek the flows up/down to get the rest of the rooms correct. Once you have that correct you have to twerk the curve. The thermostat should really be set above the target room temp, so if you get solar gain say, the flow temp is reduced to compensate.

At least 50mm is my vote

Just reread the £24 or 80kWh per day. Are you sure it's insulated? Or is it really big? and the doors open all day? If you put a log burner in, you would get no work done, you would be forever loading it up with wood.

Or if you want a high efficiency A2A heat pump. Mitsubishi Heavy Industries SRK25ZSX-W/SRC25ZSX-W 2.5kW

I think the thermostat calling for heat while weather comp is operative goes against the basic principles of weather compensation. The weather compensation basically runs 24/7, so isn't looking for a thermostat. The controller follows the heating curves as outside temp varies, and if you have a setback it just lowered the flow temp a few degrees.

If you look at some of my recent replies to other threads there are some basic heat calcs that illustrate the heat loss with and without insulation

For clarity is the builder suggesting not to insulate? Other that what are the differences?

Another alternative is a cylinder incorporating a heat pump as linked to above, for hot water only. And a small heat pump for heating/cooling.

I had heard the same, they have been saying the same for years. I have preheated water going in to the boiler via a solar PV heated cylinder, so was using the combi, topping up DHW to 48, and still using bout 8-9kWh of gas a day. I read a bit about Alpha Boilers Superflow (preheat cylinder on a combi) and the instructions made a big thing about making sure the DHW was turned up to the max, so gave it a go. Changes made early June. May monthly gas usage 269kWh (no CH heating, just DHW) June 105kWh, used loads extra messing with settings over a couple of days as a trial. Should have used around 70kWh for the month. July 64kWh August 104kWh, less solar output going spare for preheated water. So seems to have made a quite big impact, £10-14 per month lowering of DHW costs.

You've been busy.

May try upping to 70 also

How do you do it?

Wow that only an average of less than 9kWh per day. Are you bulldozing a passivhaus?

I just paid £250 for airtest, MVHR commissioning done at same time for £200.

If this is a combi I have found the same. I upped my temp to 65 and have a significant drop in gas usage. Tried at 48 and up, so 65 has been the best for gas usage.

We put 12mm2 in. Doing water pump treatment plant compressor, and discharge pump. Since installing have taken a power supply to garage, and will possibly have a small ASHP connected also.

I would check your solar gains at this time of the year. As said once the heat is in its difficult to get it out with out Aircon. Have you thought about a split Aircon system, high does heating and cold very efficiently.

We have a 192m2 floor area, UFH pipes on 300mm centres. But with a smaller area you have watch flow rates as they can easily be way to low for a heat pump. Ours is about 12-13l/m so ok for a 3to 5kW heat pump. If the floor area was smaller you need to looking at 100-150 spacing to ensure you have a suitable flow rate to keep the HP happy. Don't base any calc on having solar gain, as it may not be there. Couple of overcast days with no gain can make a big difference.

I just had a look at my boiler instructions and it states the flue should run with a slope back towards the boiler. So the flue is always going up hill from the boiler to discharge point. This is to allow the condensation to run back to the boiler.

I am in complete agreement, it's a logical easy enough plan to follow. Only thing I would add is to take all the timers off the central heating, set the thermostats to around 24 and trvs fully open. Start the testing at a weekend when you home for a couple of days.