MikeSharp01

One might ask why does nothing ever get better for customers

Yes Gus, for me it is fun, and I use aspects of it in the part time day job. Here is my latest Gizmo - an RPi Pico with a DHT22 temperature and humidity sensor attached. I have several of these around the place. This one also gathers information from the local weather station (local Temperature), gets readings from the other units (House Temperature) and interrogates the PV inverter before sending a bunch of MQTT messages to my hive cloud based broker from which I subscribe using my phone to get a great little dashboard. The MQTT dashboard app is a very lovely piece of work. See below for details. I may write all his up at some point. I won't I've using them to control anything but just to gather data I can use to set up the controls when I finally choose a system - probably home assistant. App is:

No so easy with Arable crops though!

If you are going to do this with conduit you are best advised to put in a draw string. I have used plastic builders brick line, it is amazingly strong, does not stretch, wont rot and is very thin here and have only had one issue where I was trying to pull 2x 10mm2 cables through 20mm conduit. As you pull a cable through with it you can pull in more string and it makes it so easy as does a bit of cable lube.

All sounds like a candidate for a Model Based Systems Engineering (MBSE) with simulation (simulink or some such) approach. You have many knowns, you can build assumption ranges for the rest and play away to your hearts content.

Agree it is not tat - but then I suppose from the point of view of those who like to fill their homes with consumer tat neither is theirs's, it gives them meaning, status, satisfaction, a warm glow inside, pride and perhaps a sense of personal aggrandisement. One persons tat is another's nugget of gold. I will get my coat.......

Just seeing it from other world views - for me the trick with everything you get presented with is to see it from other perspectives, perverse as I can be I like to be able to hold two opposing ideas in my head at the same time and see how things pan out from there. So I might agree a V8 is a lovely thing, but a V16 or a V24 might be seen as better and perhaps equally practical, so anyone who can afford to fit such an engine is such a vehicle would see a V8 as pointless tat. Alternatively you can take an environmental stance or any one of many others.

How do they manage the switch over and back again when the AC mains returns is it automatic?

Says he who has what many would see as a load of relatively pointless tat in his profile picture!

Feels like a question an LLM could answer so I poked mine, chatGPT, and here is what I got. When additional electrical work is added to a current EICR, the EICR renewal date typically does not stay the same, but rather runs from the date of the additional work, as a new EICR should be issued to reflect the updated condition of the installation. Here's a more detailed explanation: EICR Validity: An EICR is typically valid for 5 years from the date of the inspection. Remedial Work: If an EICR identifies issues that require remedial work, a new EICR should be issued after the work is completed to confirm the electrical system is safe and compliant. New Work: Similarly, if new electrical work is added, a new EICR should be issued to reflect the updated condition of the installation. Renewal Date: The renewal date of the EICR would then be based on the date of the new EICR, not the original one. Example If you have an EICR that is valid until March 2027, and you have some electrical work done in May 2025, you should get a new EICR after the work is done and the new EICR will be valid for 5 years from May 2025, not March 2027. I wonder if this is a slippery slope to allowing the machines to rule the world or a useful tool for the curious or both.

I am going to start a campaign to sort the basic insult that has become embodied in KISS (Keep It Simple, Stupid) - the comma is important. It was envisaged as not being an insult when Kelly Johnson a lead designer at Lockheed Martin in the 1960s first coined it, more of a note to self and to stress simplicity. Sadly it is often not used like that these days so I tend to use it now with a slight rearrangement to KISS (Keep It Stupidly Simple) which, for me, makes it less insulting when people use it talking to others. Rant over.....

That is useful stuff, I will need another glass of wine to get my head around this little lot. Thanks for putting it together.

I suspect it was the very dry way it was taught, I had done the basic stuff at A level but at Uni it had no applications shown to us unlike the software stuff, mechanical design, electronics & systems all of which seemed to be going places - or so it turned out. I was also somewhat put off by materials science but the good bit of that was, believe it or not, the wood bit - our lecturer had a thing about it.

Thanks Nick - sorry that pic was from 2017, I thought if it has been shovelling stuff up hill since then life must be fun somewhere!

That looks like the soil pipe runs up hill in the white flexi section is that allowed, acceptable, inevitable, to be avoided or what?

But how does that fit with the delta or does it drop out of the equation somewhere and it must also depend on the rate at which you put energy in or does that drop out as well. I can see that if the inside and the outside are the same temperature and you want the inside 1K above the outside then you need to put energy in to get it there and then sustain it. As I have said here before thermo dynamics was my least favourite subject at Uni and I have avoided anything associated assiduously until now. I guess my lack of attention back then is coming back to bite me in the proverbial bum now trying to get my head around all this. I also suspect that @JohnMo will be chuckling and thinking he should tell me just to KISS away the issue and, after all, perhaps we should just build on the shoulders of giants and not try and re-live all the problems the giants had getting there by starting from first principles ourselves.

Ah- yes I get it. I suppose we should be concerned with just one, in that a delta of 20K is, for this property, probably the worst case likely. To flatten that out will need heat input that matches the losses that manifest themselves in the slope won't it. Therefore the slope must, me thinks, be proportional to the heat losses the question then is wether it does or does not make a difference at the extremes and how to derive energy demand from the slope which can then be used with the delta to work out how to keep ahead of it and maintain the set point temperature. I suspect however that I may be putting the cart before the horse here and somewhat over thinking this.

not clear what you mean?

No home assistant as yet but will have when the house is finished, we do have a zigbee gateway available and zwave. I will have a look at the old posts. I suppose my concern was how fast it dropped against the delta. We have, will have, fibre cement tile cladding on the outside, 8t, which will add some heat capacity as will the rest of the plasterboard on the inside 4+t. I need to do some more modelling now I have some data to play with along the lines you and @SteamyTea suggest to get a picture of the losses so I can verify potential control schemes - probably very simple ones.

On Thursday I managed to get the temperature and humidity loggers running in the house and I now have my first scraps of data. The house has no heating running yet so all the heat going in is me working, solar gain and a tiny bit from the logger power supply. I am wondering if the decrement delay is what I should expect, here is the data from midnight last evening to now, (10:46) so about 11 hours. The upper trend is the internal temperature and the lower one the outside temperature derived from the local weather station, about 1 mile from the house. I hope to have my own external one up and running but my PoE scheme out there seems to have a problem. It broadly shows that the temperature started at midnight at about 14.2 and has come down to 13.7 over 11 hours with an outside temperature around 2 ish. Still more analysis to do but should I be happy with that rate of decline? Not sure what i can do if I am not but there are a couple of colder bridges that will be done when the MVHR Inlet and Extracts are fully fitted and there is only plasterboard on about 30% of the walls so far.

I have started down the road with them and they have accepted our heat loss calcs and that their smallest unit will do the job - so almost the reverse of this. the problem now is that the smallest unit is not MCS certified yet - they are working on getting it certified and we can proceed.

Ah - then you know who the installer was and you can pop the name on the paperwork or have I missed something. Usually at that stage they ask you to upload the commissioning certificate within a given timeframe.

We have 7kW of Eurena panels all made in Spain, price is slightly higher but not much.

I don't recall that question on our application, are you using the UKPN online form? I would have said something like this is request for permission to export an appropriate installer will be appointed.

If you build the extension to a high insulation / air tightness / glazing spec 12kW should still be OK but it depends on the % increase in size and where it is going in relation to the rest of the building. How many bugs are you intending to house.