SteamyTea

I think is is a great topic. Chance to meld mathematical modelling and process control.

PP9s and a buzzer.

I have just downloaded, for free, Python Machine Learning. Personally I don't think it needs to be too difficult. Really just a simple feedback loop based on basic thermodynamics, which is similar to an RC circuit in electronics in this instance.

Trick is to not have a freezer. I have managed without one for decades. Tinned and dried food is the way to go.

Yes. And it could be testing the MET Office prediction as much as anything else. I am going to ponder the whole problem more as I think there is merit in a simple self learning algorithms that can put the correct amount of energy into a building. This may become more useful with variable ToU tariffs as you can bank prior to a known expensive time, or take a bit of a hit until a cheap time come.

Was thinking more along the lines of deviation from binned prediction ranges. So something like this with made up numbers: Δ Temp Range Predicted Energy Input Actual Energy Input 0 0 0.0 1 0 0.0 2 0 0.0 3 0 0.0 4 0 0.0 5 0.1 0.1 6 0.2 0.1 7 0.4 0.1 8 0.5 0.1 9 0.6 0.6 10 0.7 0.8 11 0.8 0.7 12 1.0 1.1 13 1.1 0.8 14 1.2 0.6 15 1.3 1.3 16 1.5 0.1 17 1.6 0.2 18 1.7 1.5 19 1.8 0.2 20 2.0 0.8 Giving a chart like this Which give a Chi Square result of 0.985, when tested on values greater than 0. As it is greater then 0.05, then the null hypothesis is not rejected. Though that does not mean the hypothesis is correct of course.

It was a rhetorical retort to @ProDave's reply. Book is OK, even if 14 years old now.

If there is a fork truck in the building, then block. If an office, then look at timber frame and cellulose insulation as the sound deadening is impressive.

Is in my place as well. Generally less than a °C. And I have basically no control unless I manually twist the input and output knobs on the two storage heaters. Still be interesting to run a Chi Square on it as that will check the formula/equation/algorithm, rather than the outcome. Maybe @DamonHD can have some input as his devices are trying to do the same, but via a different pathway (and they may have got a statistician on board now).

Took me over 20 years to realise how to do it properly. And how to manage people, especially my boss.

I know, just I am a bone idle (expletive deleted). One of the reasons I do what I do is that I have a very decent work/life balance. Friday night was a bit fraught with the unexpected power outages and half term, but within 15 minutes of closing (sold out), we were joking about it. Some jobs/companies, when you have a really bad day, have a lingering, negative feeling on for months. I have tried very hard to get rid of that attitude as I know that everyone is doing their best in a fast moving, and changing, environment. And I get paid more than my mate who is a very good thermal engineer in the biogas field. But can I do those jobs remotely when I am sitting in a cafe, or just overlooking the sea? That I would be interested in.

Do you every run a stats test to see how what you hope your algorithm is doing, and what is really happening? Should be fairly easy to compare temperature stability with energy input.

Does that take purely the drop in internal temperature, regardless of external conditions?

"We overvalue diamonds, and undervalue fresh drinking water"

That is quite far from the complete picture. Oil,_a_beginner's_guide.pdf

Seems most of the problems near me have been caused by fallen trees. Not as if WP did not have enough warning.

3 had proper science degrees. They are the ones that will move on.

Last summer, we employed a number of degree level people. Some will move on, others will stay.

I would always smirk if I had to use batter with this name.

How does it compare to someone on minimum wage doing the same job? People working in catering have to, generally, pay for their certification to even get an interview, and supply own clothes/wash uniforms. Oh, and they don't often get more than a few hours work a week.

Tell me about it. Last month spend £600 on diesel. Almost a years worth of electricity for my house (<4 MWh I think it was).

Not sure if 2020 and 2021 numbers are in yet. https://www.gov.uk/government/statistical-data-sets/regional-and-local-authority-electricity-consumption-statistics#full-publication-update-history

I have, as many of you know, E7 heating. By the very nature of this, there is a switch off set time (7 AM UTC). Because my water and storage heater would come on at 11 PM, then off for an hour, and back on at 1 AM, I put lock out timers on each circuit (my time window has now changed to midnight to 7 AM). This was to stop things heating up, then cooling down, then heating up again. I currently have the E7 time window effectively set as an E4 (3 AM to 7 AM). This gives me plenty of time to heat everything up. I have often thought that a variable time window could be useful, but rather than along the lines that @TerryE uses (signal from MET Office), just looking at the rate of change of the OAT between 8 PM and Midnight could be used to set the start time for the next day's heating window. I have quickly plotted a few years outside air temperature (OAT) binned it by rate of change in the above 4 hour window and correlated it with the mean OAT. Needs a bit more thinking about how to use the slope of the time to set the length of the heating window, but I feel there is a reasonable correlation to be useful. I know from experience that my heating has to come on when the daily mean OAT is below 10°C. There does seem to be a half decent correlation between the night before temperature change and the day ahead mean temprature. Below is a quick chart showing July and February slopes. These are my two extreme months. Needs a bit more thought, and how to integrate it with the building heating curve may become tricky. The aim is simple, the heating turns off at the set time with just the right amount of energy having been delivered, and no more. The objectives are much harder.

With a generator the voltage and frequency is not always that stable (not sure how good inverter generators are). I think that would cause the PV inverter to have problems.

Ah, the church. An organisation that has invisible friends and worships lack of evidence. If IR heating was so good, we would all be using it.