SteamyTea

Yes, it will, as it is a small problem. But take another scenario, say a refurbishment to a lower standard, and with the original boiler, then it is a totally different kettle of fish. Or using E7 and regular storage heaters, which are still one of the cheapest overall methods of installing and running a heating system. Variable time of day (TOD) energy pricing may make this a more important issue in the future.

Starting to seem to me that heating control is more about prediction that the actual switching on and off. There are two statistical methods used to predict weather, both based on observation. Frequentist: This relies purely on the distribution of past events. The output is a probability rather than binary. Baysian: This is still based of past events, but allows a known event to be discarded. The output eventually becomes binary, which is useful. I am not sure how reliable getting a local weather feed from the WWW will be. It is rather at the whim of the weather station owner and the feed could be pulled at any time.

Ever industry has its own 'language'. There is a theory that it is to keep people out and promotes protectionism. Having just been away for a month, I noticed that 'the locals' spoke in statements, one sentence, one meaning, only. This stifled debate and was quite tiring to listen to. And they had no idea about irony and general humour.

The problem with solar gain is that it is very location dependant. On my cheap 'weather station', basically a clock, a thermometer and a pressure gauge, it is amazingly accurate in predicting sunny days. The only outside measurement it can make is air pressure. I wish I know how it worked as these things are sold world wide. It may be possible to point one of those IR thermometers up into the sky. The colder it is, the clearer it is. The most reliable indicator that I know of is wind direction. Not 100%, but pretty good in the UK.

So if it was as simple as just plugging in a 'thermostat' or two then that would suit most people. The logging can go in in the background without them knowing. I was more thinking of a very simple device, basically a temp sensor and a knob to set the temp, the clever bit would be behind the scene in the 'box of tricks' Not really any different to what most people are used to.

After a slight hijack on another thread, I thought it best to start one a bit more dedicated to heating control systems. Some of us like playing with wires and stuff, other are happy to buy in a system. This may be a good place to combine the pooled knowledge, and pinch a few ideas. If I get time today (decorating bathroom) I shall try and post up some thermodynamic theory. But no promise on that.

I am going to start a new topic on heating control as a few of us are practical and like the subject (and got a box full of RPis and components). https://forum.buildhub.org.uk/topic/4142-heating-control-systems/

I suppose it is, with a bit of automatic curve matching (which is not hard, though the coding my be tricky).

Rather than worry about the hysteresis (a word I still not spell or pronounce), could a thermostat be set to a temperature and then use a timer to delay the on/off period. So say it takes 20 minutes for the room to cool by 0.5°C, onces the set point is set, there is no way the heat source can add to it for at least 20 minutes (times and temperatures may vary). This would stop short cycling. A similar idea could be used on the heating cycle but would need two set points, the upper and lower. Once the lower set point is reach, the heating system stops. That is really just a smarter hysteresis idea, but with some lock outs. I would think that it was a pretty simple thing to DIY.

Sounds like the cylinder is loosing a fair bit of heat, how much insulation does it have?

I might be miles off here, but can't you get some GRP made up (or do it yourself, Faye is a clever girl), easy enough to get the sizes you need with the right (simple) tooling.

So I am just playing about with some local weather data and at noon today, I could have got, with a south facing 1 m2 window, 177W with double glazing and 188W with triple. At 15:00 I would have got -1.8 W with double and 12.5 W with triple. At 9:00 it would have been 5.8W or 22.4W At best, with the solar power at 368W, I would have got either 298W or 309W, for 5 minutes or so. Go for the triple.

I worked the U-Value out as normal, so W.m-2.K-1 . m2 . (T1 - T0) For the radiation I multiplied the G-Value by the area, product of the cosine of the azimuth and Altitude angles and the solar power. Something like (excel is a bit different as it uses radians): G-Value (decimal fraction) . T-Value (decimal fraction) . Window Area (m2) . Cos(azimuth angle) . Cos(altitude angle) . Solar Power (W.m-2). Then took the Thermal losses away from the solar gain. Try it, but change the extension from txt to xlsx. I may have made an error. Just don't input anything in the last 3 cells, they are the answers (B14, B15 B16) Solar Gain Calculator1.txt

Just though, I have a pair of Dunlop, steel toed, trainer style shoes from that cheap 'sports' shop. The one that treats all customers like shop lifters. They grip reasonably well on a wet floor at work and only cost about 22 quid. Think it is these and they have gone up: https://www.jjbsports.com/dunlop-safety-iowa-mens-safety-shoes-181001?colcode=18100103

I just did a quick and dirty spreadsheet. For a solar input of 100 W.m-2, a solar azimuth of 45°, an altitude of 20°, with a temperature difference of 15°C. Using a U-Value of 0.5 and a G-Value of 0.5, I make it 62.7 W.m-2 (1m2 window). That is the basic triple glazing from the chart above. An old light bulb would give you that I think. When I change it to a U-Vale of 2.7 and a G-Vale of 0.78, I get 34.9 W.m-2. That is a basic double glaze from the chart above. (always a chance that my spreadsheet is wrong)

Do the sums for different radiative forcings i.e. 50, 100, 150, 200, 250 W.m-2.K-1 Then decide of you can actually shift that energy to the rest of the house. You may find that you can suck more energy out between the roof tiles and a small gap under them. One of the misunderstanding is that when stuff is heating up, that is all it is doing. It isn't, it is also loosing energy at the same time and at a faster rate the relatively hotter it gets. Just today, in my comic, there was this question answered.

And that is just Janners, try the lot further west

Data, data, data. Apart from that, where is the thermostat. Does the sun hit it at all and is it in a draught? Apart from that, do some test. Set it at the desired temperature, say 20°C, note the current internal temperature, the external temperature (maybe an external wall if you have an IR thermostat) and keep checking every 15 minutes and note the internal temperature. If you can, note the time the ASHP stops too. Do this for a few days and then try again with the thermostat set at 18°C and then at 22°C. Plot it all in excel and it will all make sense. You need two plots, internal temperature against external temperature and internal temperature against time. From that you can work out any offset needed for a given external temperature and the time taken to heat the room up to a set temperature. Put some tape over the thermostat when you do the tests, or cut fingers off, both usually work. For a change, I have my heating on (I think I am getting older). Front room is at 17.8°C. This would usually be a bit cool for me, but as I am decorating the bathroom and running up and down the stairs, I feel a bit warm. Too warm for a change.

Welcome May I ask why you want to build with straw? The thing with money lenders is that they went to claim back more than they ever lend, it is how they keep in business.

Gone off topic on this one a bit, Sorry Dave.

But they don't care, they charge £2.40 a cup (half that in Canada). I did notice that the water was over chlorinated when I was away. Not something that I have noticed in Cornwall or in Bucks, though the water in Bucks is so hard it comes out in lumps. I don't know why this was as the geology in NS is pretty similar to home.

I think that wix.com have blogging, you would have to check. Biggest problem with the free sites is the amount of space they give you for nothing, and any adds of course. It is pretty cheap to set up your own website.

What is stuck in there, or more to the point, who!!

I still think it about time that 'we' created a nationwide wireless mesh network. It may not, with current technology, be fast enough for video or a fraught teenage girl updating instafacetwit, but could be useful for sending simple and small data messages like energy readings. Just how hard can it be to rig up a Pi ZeroWs into a mesh and pop them in the car (we are usually not far from a car or several). Accessing could be via Bluetooth, that is also built in. One thing a network like that would do is force people to start thinking about bandwidth again. I went to a website the other day and there was a massive 250mb video on the opening page. The page would not even start until it had all downloaded. How stupid is that.

I have found that any clean install is pretty quick, then it gets slower and slower, then unusable. I hope they get most of the add-ons updated. Ghostery works though.