JohnMo

How big is your new build ICF house to require an 8.5kW heat pump? Let's is know U values, size, single storey etc, airtightness and UFH or rads? I'm at around best part of 225m2 (including plant room) and have just installed a 6kW and could have got away with 4kW. Assume the quote doesn't include the heating system as nothing is mentioned? To me the price looks like a total rip off!

You to understand their age, then find a datasheet online and estimate how much they have degraded and much remaining life is left.

We have a concrete over UFH with no screed. But had to self level the low spots and it took a day to grind down a high spot. But cost a couple of hundred pounds including the grinding attachment for an angle grinder. My labour was free.

Look at the interest rates, for a self build mortgage and to remortgage your house. Add in rental costs if you sell. It all a numbers game. We kept our old house until I started to run out of money, then sold it and car to find the rest of the build.

MCS or not MCS makes no odds if the electric operator has restricted you. You can save lots of install by not going MCS, but never get paid for export. I chose the not MCS route. Your other option could be G99 approval. Here you pre apply for lots of generation, but use a G99 approved inverter which limits export to about 3.6kW or less.

Really depends on the equity you have in your own house, if you have room to spare just increase the mortgage on your own house, and arrange so you don't need to draw it all at once. This should save some interest payments. Talk with a mortgage advisor.

You need a solar diverter. Good in summer not that good in winter. As the amount of solar irradiance is low.

I insulate all DHW heating flow and returns, but where it splits to go to UFH manifold I have left it uninsulated as it's useful heat.

After 10 years your performance will drop circa 10 to 15%. Paying loads will not see a return on your spend. That's for 1kW installed, so about 3 or 4 panels.

Out of interest NE Scotland with same data inputs - winter production for me is rubbish compared to Manchester

Read somewhere that in the 60 or 70s when central heating first started the house target temp was something like 16 degrees, now we get people who want and need to have 23, or they will die, then complain about big bills.

Move map about find your location mark it with curser. The other boxes where there is a red star click on that it explains what the box is and what you enter

Must admit being similar - but building the house I calculated everything I could and heating and DHW I had a good idea of what my bills should look like. Then I got my first bill it was twice what I was expecting. I really started monitoring gas usage, daily to understand what was happening. By the end I had the boiler operating at around 110% efficiency, so getting better than the calculations. Got that sorted then installed an ASHP using all the learning from the gas boiler on very low flow temps. Previous houses just paid the bill - didn't know or care to much bills weren't that expensive anyway. Gas was so cheap.

The measure of electric are kW that's the power, kWh is the energy usage. So a 3.4kW array is the max power the array can generate. If it generated 3.4kW for an hour, that would 3.4kWh, if it generated for 2 hours that would 6.8kWh and so on. Panels are generally sized in watts (W). Panel sizes carry slightly depending on efficiency. My 340W panels are about 1.7m X 1.0m each. So 10 panels in a line would be 10m long by 1.7m high. Do the maths on pay back, electric is 29p per kWh, so you have a lot of kWh to generate to pay back a £10k spend. Have a play on here to take a look at yield. https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html#api_5.1

If only I could. Although living in Scotland it's not applicable to me. Not sure it does. If system is running weather compensation and system balanced, they can turn the heat up as high as they like it will have little or no affect, without changing WC curve also. Turning it down will act as temperature limit stop. Admittedly if they screw most of the thermostats down and leave one one high, they could so only one zone is engaged. If it a radiator system the type of TRV installed so the flow is never completely closed off would fix this. Owner education on how to operate the installed heat pump, how to use controls including thermostats should be part of a well engineered and balanced system.

Interesting it may the difference in location me being a further North in NE Scotland, has a reduced yield comparatively. Plus we are home all day, to make use of the electric.

A few things to consider If you wish to sell the electric generated the whole install needs to be done by a MCS installer. You pay more, but you can sell the electric for 5 to 10p kWh. Not MCS, means you source everything yourself and just about anyone can install. But ideally the electric hook up would be done by an electrician. Plenty of companies are out there that provide full kits. Batteries, if you are installing 3.6kW array, you can self consume everything you produce, so battery benefit in my view is questionable. Roof integrated requires no tiles below the the solar panels, so saving are made there. Pretty straightforward once you get your head around it. Basically the PV panels connect together, go to a DC isolator into an inverter, to an AC isolation switch and then to your consumer unit. It's never plug and play, so don't let anyone convince you otherwise. But it shouldn't be complex. I am in the process of installing a ground mount array of 3.6kW for a total cost under £2000. I have a combination of new and used parts. This is not a MCS install, if it was it would cost 3 to 4 times more.

We had a clay soil garden and had loads of issues in the end we rotovated tonnes of pea gravel and organic matter. But we also had perforated ducts below the conditioned soil, to take away excess water.

You need to shop around to not pay stupid prices. I rang around local electrical trade places. Prices varied between £70 for 3m plus vat, collect only. I used Medlocks and paid £40 for 6m lengths delivered. All quotes were for 41mm square undrilled.

You need to at the install manual for heat pump, but your clearance either side doesn't look enough. Search Google for MCS 026 (think) or MCS noise, you are looking for a spreadsheet or pdf that walks you though the noise calculation. Do you need concrete, my ASHP just sits on gravel.

One is an additional pump in the system return, will require anything from 12 to 33W depending on pressure drop experienced, this will compensate for increased pressure loss through the system. I use one on my DHW heating, due to very long length of 22mm plastic pipe. Works a treat, mine is on only during DHW heating. Sorry I don't make the rules, but I believe, in the interest of boiler efficiency etc (aim should be over 100% efficiency - mid 80s to low 90s efficiency should be no longer acceptable. Therefore all new boilers sold should not be capable of more than 55 degs for central heating and should, if not a combi, be configured on to work only on priory hot water or X plan. S an Y plan banished to history books, the same as 70 deg radiators. As both should have been in the 1980s when condensing boiler first became available. Also while I'm on a roll all new cylinders should by law only be able to be sold if they are heat pump ready i.e. 3m2 coil installed, even in a direct cylinder. As @HughF if want an easy drama free install go for A2A and direct cylinder (but with a 3m2 coil pre installed).

But that's down to poor system balancing. Existing room controls can easily be reconfigured to operate what ever regime you require. How they interface with the heat pump require change anyway as it's operation is different from a boiler. What you are explaining is why heat pumps are deemed expensive to run, it all the wrong ways to operate a heat pump for good efficiency. Having one room hot and all others cold, means the heat pump has to work harder to compensate for the heat transfer to the colder areas. It would be more efficient with an electric panel heater. You can't have a drop in replacement for a combi, as you will require a cylinder or a means of giving DHW on demand. Any new heating system has to be designed for a max heating temp of 55, so some work would be required to radiators in most cases anyway.most likely. Lots of ways to get around pipe size issues, so that's not an issue.

If you are running weather compensation, which all ASHP installs should be, then the room by room temperature control will be for overheat protection, rather than direct room temperature control. So there is zero requirements for the room temperature control to call for heat. Heating room more or less than others is simply a matter of balancing. So by default why would anyone require a buffer?

First time I've use it, angle grinder, drill and galvanising spray and away you go.

Not that's really anyone here thought about when coming here. I came to Scotland kicking and screaming, being told I was being posted here with the RAF. That was in the mid 90s. Met my wife here and here we stay. Water didn't even cross my mind. But weather here is good, not as hot in summer as England, not much rainfall, compared to the rest of the UK (small micro climate). Generally mild winters except for last year where we had -9 few weeks.