SteamyTea

Health and Safety. I interpreted that as hen pecked with small genitalia, but kept that to myself. While you are here, how did you manage to block me from: https://forum.buildhub.org.uk/topic/10651-are-plasterers-the-worst/?do=findComment&comment=179803 by quoting me. And I still can't login from my phone. Did use the Contact Us link, but seems there was no one at home that day.

There was a long line of cars to get into my local tip. I drove past them, parked up in the layby, got my single black bag of household waste and walked into the tip. Was told in no uncertain terms that I was not allowed in. I was 5 feet from the container. When I mentioned this over at the other place, our old mate DamonHD said he had a similar problem, as he had no car. He organised, with the council, a 'pedestrian day'. A day that normal Londoners, who don't own cars, can take stuff to the tip.

You keep mentioning this, but you are saving on imports, anywhere between 12p and 24p/kWh, depending on your tariff. If you save 2 MWh on import, that is somewhere between £240 a year and £480 a year. Not to be sniffed at.

Yes, I agree, but was highlighting the problems of choosing the correct battery/storage size, and the importance of data logging.

Trouble with that is it just gives daily, weekly, monthly or annual loads, does not help much in finding out when you import and when you would export. May be worth getting an energy logger and finding out what you use in your current place. As an example, I found out recently that I import no energy 60% of the time. That is not a contiguous 60%, but a few minutes every half hour or so. Below is an example of a typical day.

Next time you chat to him, ask if he has decent weather and crop yield records. Many farmers do.

By this do you mean different scenarios, or actual climate regimes? The UK is a tricky place to model climate for, it depends so much on local weather, which can significantly vary over a few miles.

Probably partly due to the abolition of FiT and new system not up and running yet. There is also the issue that once you have installed a system, you cannot put another one in as the roof is already full. DECC spreadsheet here: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/819771/Solar_photovoltaics_deployment_June_2019.xlsx

I would like to know as I can then cobble something together and monitor @joe90 Do you actually need to know the flow rates, can you just make assumptions based on the input and output temperatures? Bit like working out the efficiency of a heat exchanger.

We used to fit toughened glass doors to saunas and steamrooms. They did shatter, but not because of the heat. Usually happened when trying to fit them and they slipped onto the tiled floor. Then the fitter said 'It just exploded'. If anyone knows Swedish, a popular country for saunas, they always agreed with me about the fitters.

Right. Shame, WeatherUnderground had a historic download option, but that seems to have gone now. I think you can specify between dates in the URL, and get it to display as text. I just wish it was as simple as it was, type in dates, download the text, import into favourite data package.

If i just uses resistance heating then probably no, though there will be some parasitic losses. Not so sure if it uses stored hot water. There may be a rare scenario where it pumps warm water back though the system for too long, and if it has had a very low CoP just before, it may dip below 1. I am starting to wonder if icing is a real problem. It may just happen when trying to raise the temperature to much for too long i.e. an undersized system.

How do you get that, I had a quick look and could not see anything obvious to download it.

We should have really put the construction type, cubic metres to wall area ratio and main window direction in. Then we could see what sort of difference they are making.

Really just wondering if there is any merit in the idea of sensing CoP and using that as a control. Trouble is I think, that we want a fixed amount of energy out of an HP in as short a time as possible. But that is often not the best way to run them.

£50/hour

My sister probably still does that when she gets in, but usually the hot pipe under the bathroom floor. Many a time I found her.

A comment in @Conorthread about heating water got me thinking. https://forum.buildhub.org.uk/topic/10668-small-ashps-units-primarily-for-dhw/ Does heat pump constantly monitor the CoP, and if it does, it should be possible to only run it when it is over a set limit i.e 2.5 or 3. If it does not constantly monitor itself, then it should not be too hard to make a monitor and switch to make it do so. The reason for this as that it should avoid any icing issues, though it may reduce the overall energy delivered, just when you need it.

Took this last year, but not unusual at work. Bloody hot to be physically working in.

Current sea surface temperature at Penzance is 18.4°C That is both 20° too cold for swimming and 20° too North.

Right, 3 temperatures. Max outside temp so far today is 24.3°C at 13:08 to 13:22 Max house temp is 22°C at 13:33 to 14:40 (so may carry on a bit) Max window cill temperature is 25.3°C at 10:03. The windows were closed as I was out. Cloudy and a bit breezy here today.

Needs to be checked out or we risk giving wrong answers.

Shame Would take 90% of the guesswork out of it.

Not exactly opposing, they can both apply. Don't think you can under MCS rules, they closed that loophole a few years back I think. It is the installed capacity of the modules that the DNO is concerned about. Worth checking though as things change. @Dan Feistdo you know your current usage pattern, that can help. As an example, I use about 1 kWh/day for my general use. All the rest, somewhere between 3 and 20 kWh/day is on E7. Those loads I could shift to PV/Storage if I wanted to. Failing that, use the Golden Ratio, 1.62 kW installed capacity to kWh storage. It is probably as valid as any. @JSHarris have you got, or can you dig out, daily data on how much you use and how much you export. The exports could be considered the optimal battery size needed. Then you can take away daily imports and see what is 'wasted'.

Luxury