Marvin

Yes, adding to a false sense of security as to the future cost and ability of servicing debt. If you believe "When America sneezes the world catches cold" watch America as they catch a cold.

Hi @markocosic Now we have invested in PV were not interested in giving it away. The aim with PV should be to reduce the amount of power you need to buy. Selling at 8p per kWh and buying it back at 40p per kWh is of no interest to me because in the winter we will need to buy a lot of power which would cost more with such a deal. ( summer sale v winter buy back). We also charge our EV from the PV. You touched on another point: we are also setting up an off grid battery supply of power which will be isolated from the mains, but charged from excess PV. Whilst we cannot store lots of power to last the winter (not without £80k haha!) the aim in to try and cover the background usage over night which would save about £550 a year at 28p a kWh. The on off thing with the ASHP is tricky but can be done: a timer, switching a minimum 20amp relay ( I would use about a 30amp) on and off would do the trick. However I would only be turning it off in the summer months, so I will need to calculate the cost saving benefit, as at the moment I just flick the fuse switch. Good luck M

Yes this was my thinking....

This was the start, and interestingly Russia seems to have been part of the mix along with more energy required for Asia and industry generally. https://www.bayes.city.ac.uk/news-and-events/news/2021/september/what-is-behind-the-rising-gas-prices

Hi @Kelvin If you are self building your own place then in my humble opinion you are right, the best thing you can do is build it. Good luck M

IMHO I think personal debt is already out of control, caused by the reliance of never ending low interest rates and large borrowing giving rise to a false sense of security as to the future cost of servicing debt. People are already facing bank of England interest rates seven times more than it was this time last year. August 2021 = 0.25% August 2022 = 1.75%. and I do not expect it to go down any time soon.... Many governments have been "printing money" for a few years and propping up the economy when they should have corrected the problem by raising interest rates (including ours): Kicking the can down the road. This will all end it tears.

You can check the bubble works by putting the level up the right way and comparing the bubble position as it is, and turning it around front to back and putting it back it the same place as before and the bubble then. If they're the same then everything's fine.

My guess is that the barn is in Italy

Hi @SimonD Think your right with all you list but there's a few more I would add: The distance between the external ASHP and the buffer tank. The location and insulation of the external pipework. The location of the buffer tank ie in or out of the thermal envelope. Also, and different to a gas boiler, the lowest temperature strategy which would give the ASHP the highest COP. This may be for instance heating the UFH up during the afternoon to last all night. Also again, an ASHP will produce a better COP when the difference between the demanded water temperature and the external air is the least, so choosing when to use the ASHP is also an important aspect. Generally, heating your hot water during the afternoon will use less electricity than at 4 in the morning because the temperature difference is usually less.

Hi @ProDave We do not heat the water above 45C when using the ASHP (However I would like to point out that the tank temperature is very different depending where the probe is. At the moment the high probe says 71C and the ASHP probe says 48.9C Perhaps I written it wrong... let's try 4 scenarios: Use ASHP on all sunny days ASHP heats hot water to 48C for 3 days: Lets say 6kWh. ASHP on standby for 3 days: about 6.75kWh Total power about 12.75kWh but at least 2.75kWh purchased for the hours from 9pm until 7am Immersion heating system on all sunny days: Set to heat to 70C: Uses about 9kWh of FREE power (well 10 pence per kWh from the PV) Use ASHP on one sunny day and 2 cloudy days: ASHP heats hot water to 48C for 3 days: Lets say 6kWh. ASHP on standby for 3 days: about 6.75kWh Total power about 12.75kWh but at least 2.75kWh purchased for the hours from 9pm until 7am and 3kWh for the cloudy 2 days when not enough PV. Immersion heating system on one sunny day and two cloudy days: Set to heat to 70C: Fills up on sunny day and trickles bits in on 2 cloudy days. Uses about 9kWh of FREE power (well 10 pence per kWh from the PV) One way we buy electricity, the other we don't, or at the very most it cost us about 10p per kWh for the system. On cloudy days if we only have 0.5kWh spare being generated when the ASHP comes on it will grab 1kWh from the mains. Secondly the PV power not being used varies from moment to moment but the ASHP cannot currently accommodate this change but something like the Solic 200 can. Low and slow is the immersion way or high and fast, but either way only with excess energy. And finally I would rather wear out the £50 immersion than the £3180+VAT ASHP! ( Goodness I am having to proof read all of this to try and avoid Steamytea's interventions)😂 Hope this helps to explain M .

Took us £360.00 and 3 months to get DNO permission to go over the 3.68kW installation....

Possibly secret screwing at 45 degree angle into joists?? And then seal between joist edge and edge of Wood Wool?? Alternatively, stick to underside of the 70mm insulation (what keeps that up?) and or seal edges. They seem to have good acoustics.... probably quite helpful with a vaulted ceiling. That as good as I have I'm afraid. Good luck M

This one may be of interest to you @Conor Think you have PV....

The Solic 200 that I have will only allow up to a 3kW immersion. We have 5.12kW PV installed. Wish I had room for 9.98kW PV ...... We could do it but we would have no garden left. M

Goodness your busy! will do

Yes. Any brand will do in my book as long as it works. I think some can be connected to more complicated setups but ours is simple.

Yes.

Results for us as they come forward...(and not what I expected) Our Cool Energy inverTech Air Source Heat Pump CE-iVT9 4.3kW-9.5kW has been on standby only, for the last few weeks, and I have measured the power consumption. It appears to use about 0.1 kWh an hour. That's about 2.25kWh a day in 24 hours. We use a Solic 200 to direct our excess electricity produced by the PV to the hot water immersion. Whilst the Solic way of heat the hot water uses more energy, because it only runs using power we would otherwise give to the grid, its better for the bills to turn the ASHP off all together rather than use it to heat the hot water tank. You would think that with a high COP it would be better to use the ASHP but with the other things on in the home and the car being charged, you can never be sure your not buying all the power. Secondly I think the ASHP runs at a minimum of about 1.5kW when heating the water. The Solic can use any spare power from the PV: 10 to 3000 Watts. We could turn the ASHP off altogether and on only when we need hot water and I have decided this is a bit fiddly so won't do it. Another benefit is the fact that the hot water tank is set to 70C ( the ASHP will only do up to 60 and that is at its least efficient) and this lasts us at least 2 or 3 days before needing to be heated up again! ( We do have a super insulated tank) Days when it could be cloudy and we would have to pay for the power. ( We will turn it up higher in the winter and use it as a thermal store for night time warmth...) And finally I would rather wear out the £50 immersion than the £3180+VAT ASHP! Good luck with your project. M

Hi @Meabh Lots of good stuff above... As you are building new you could choose either the gas or the ASHP route. As @JohnMo says the zoning could be tricky. But not only for heating but also for cooling (if your using an ASHP) and the MVHR system. @ProDave hits the nail on the head about peak heating demand. I designed our home to heat to 23C when the outside temp is -8C - four degrees below the lowest temp here in the last 10 years. Also I put as much PV on the roof as possible. - great advice if your going for PV in my book, especially if have a Solic 200,an ASHP and/or EV (Electric Vehicle) We have AIM (Airtightness Insulation, MVHR) and APE (ASHP, PV, EV). AIM works well as a group, and I think that's where your at. I have a different opinion than some about using PV. APE also works well as a group. We use the PV to heat the hot water 205 storage tank using a Solic 200. When the ASHP is not needed for heating or cooling we turn it off as on standby it uses about 93Watts an hour, which is more per day than we would use to heat the hot water using the Solic 200. We have had hot water by this method for weeks now. Also it stops the need for the cooling ASHP to suddenly change tack and heat the hot water when cooling the home on a hot day. As @Carrerahill says most of the UK housing stock fails to achieve a suitable standard for ASHP ( poor AIM levels). Good luck M There have been many discussion on Build hub about ASHP installations and I am of the opinion that from an installation point of view they are more technical than a gas boiler with regard to positioning the various items and they are more complicated to programme and fine tune for each individual property than a gas boiler. That being said we are happy. Our EV is at home most of the time and we have charged it up fully buying the power about 5 times this year. Most of the time we use a little mains or no mains at all when charging. When home and not full we plug in the car and through the use of CT clamps and relays we slow charge the car when the PV is producing over 3kW. We estimated that our PV power costs about 10 pence per kWh assuming it all lasts 7 years. We achieve about 4 miles per kilowatt.

Hi @CarrerahillThanks for your info. I did think of moisture problems, that's why I was thinking of filling using a foam gun. No air inside no moisture inside? I did think of drainage at the bottom, However I was concerned with the water table.- No rain here for 7 weeks and the soil at 1.2m down is very damp. Would it rise up the steel box when the water table rose again....?

Yes I do the same. 👍

Hi @Conor, Thanks. External metal all to be painted. Below ground. Good idea about the bitimous based paint. I will use it below ground.

Thanks yes not structural. Has Postcrete the same density as concrete (i.e. not porous)? Would it be best to let the concrete rise up in the box steel or cap the bottom off?

I have to fit two 3mm bare steel 80mm by 80mm box posts into the ground. There is no room for a base plate and bolts to fix them to a lump of concrete so I am going to treat them like fence posts. As the first 400mm down in the hole is unstable due to decking etc I have dug a hole 1200mm deep to take the posts. I am going to use Postcrete The posts will stand about 2400mm above the hole and have a horizontal force of about 60kg at about 2700mm above the solid ground. What are the best options to avoid the post rusting when its in the ground. Obviously painting the outside and covering the top. Paint the inside? Foam fill the inside? Concrete the inside? Cap the top and bottom? Vent the top to let humidity out but no rain in? Wrap the bottom in plastic but make sure no water can seep between the plastic and the metal? Suggestions please.

SWMBO said the same.