SteamyTea

I planted 2, one seems to have died. I have been expecting rain, but looks like ti will start on the weekend, just as the school holidays start.

I forgot you are on E7 now. I really must have a look at my electricity costs. For me EDF were always been the cheapest (far end of the power cable), without exception, but they don't seem too competitive at the moment. Trouble is, there is only £40-60/year difference on my usage. I can easily save that by putting an inch less bath water in. If I had a spare £10k, I would drill a borehole for my water and get a small HP to heat it up. But as that is about 15 years worth of energy, hardly seems worthwhile. It is like planting a tree, should have done it 15 years ago.

Don't you get the deemed export and the actually generation payment, tax free?

What Solver is for, or do it the easy way and just work out the hour by hour means, then add in the incidentals. Then hit F9. I think because I don't draw anything from the grid 60% of the time, I should get a discount.

I could sit down and work out an estimate for the ACH based on HDDs, but it would only be a rough estimate. Apart from a bit of extra insulation in my loft, changing the glazing from 3-8-3 to 3-16-3, making sure the old frames fitted correctly and a bit of extra draft-proofing around the back door, I have done nothing to the house. When I first moved in, and having been used to an old Victorian house, but with a gas combi boiler, I was a bit fooling with energy. My first years usage was almost 12 MWh, now it is about 3.8 to 4 MWh. So about a third of the usage. A large part of this was DHW, then I saw just how much I was being charged for water, so cut back drastically. It is also a testament to just how good timber frame houses can be. Mine is one of the first 6 of this design in Cornwall, then they build hundreds of them, if not thousands. Apart from when I went away a couple of Autumns back for a month and did not leave any windows open, I have had no issues with condensation. Condensation may be a concern if having a low air temperature inside the house and the ventilation is not idea. No amount of FIR is going to solve that. It would be an interesting area to study. Something I had to do as a first year degree student. Seem to remember the hard part was making the spreedsheet look pretty, rather than the actual calculations. We were given the temperature and ACH to work from, which made life easy. Was possibly that assignment that made me interested in thermodynamics more than any other, probably because it was a real world problem, unlike what I did for my 3rd Year project, which was, in a way, similar, but a lot of equations and calculus to prove it.

Happened in the Health and Leisure industry. A few suppliers created an organisation basically to keep some suppliers out of the industry. That all changed when Local Authorities had to go to competitive tendering. I don't think the Fitness Industry Association in the UK is about anymore, possibly because it was started by a serial bankrupt and his mistress.

I often think it is because we use the word heat to mean temperature. Must be time for our favourite song.

Why not. It only takes 1 joule to raise 1 g of air by 1°C I have 1.2 tonnes of air in my house and 48600000 j a day to use. So if there were no losses at all, then I could raise that 1.2 tonnes of air by 40.5°C. Heating air is easy, though it does take more energy to heat than granite [SHC of air is 1 J.g-1.K-1, granite is 0.8 j.g-1.K-1]

I am in Cornwall, we do things right here, not like that lot in Devon, ask @joe90about planning in Devon. Devon is just a place one has to travel tough to get to civilisation.

I suspected that you were getting muddled between installed capacity, energy and power a while back It is an easy mistake to make, most of us do it. It is important to make this distinction otherwise the calculations for efficiency just become nonsense numbers. A watt [W] is a joule per second, both Watt and Joule were people, it is why, under the SI system the abbreviation is upper case i.e. W, J, but written in full starting with a lover case. a kelvin, which is named after Lord Kelvin, is the same. You don't have °K, that is saved for the celsius scale, which used to be known as the centigrade scale. Celsius was a person, so C when shortened, celsius when in full, unless talking about the man. A Wh is the energy delivered, stored or available and can be in many forms, but basically come down to kinetic [moving] or potential [stored]. This is a small unit, so is usually prefixed with a k, M or G for kilo [1000], mega [million], giga [billion]. So a kWh, not Kwh, or KWH, or killa wot our, is made up of smaller units, joules and seconds. A second, is not named after a person, so is lower case when abbreviated. So there are 3.6 million joules in a kWh, 1000 joules per second, times 3600 seconds in an hour. Just to put that into perspective, a joule is the force needed to move 1 kg 1 metre. Force is mass times acceleration.

Yes, and his installer of the UFH only added 25mm of insualtion. That is the energy per floor area calculation, not the power calculation.

If you already know the power, or energy, needed, there is no reason to do full calculations. But when I did, I got a similar result. Having done full MCS/RHI calculations via software and manually, I find that they generally match existing usage. To give you an example, I was chatting to a fellow that had UFH and an ASHP fitted. He was saying that the running costs were not much less than his old oil system to radiators. With a bit of questioning, I found out the house was a lot warm, around 6°C and he used to heat DHW with an electric immersion heater.

281 Wh.m-2.day-1 kWh = Energy kW = Power

The UK mainland is tilting about 3mm/year because of the last ice age, which pushed Scotland downwards. Then add in sea level rise because of ocean thermal expansion of about 3mm/year.

It is rising at about 6mm a year asl. I am sinking at about the same rate. It is not so much the mean sea level, more to do with storm surges. We had one a few years back, it was quite interesting to watch it, the harbour visibly filled up (smashed boats too because of waves).

Small, terraced house, fairly airthtight, mild climate in Cornwall. The technology is just old Creda storage heaters, but I do limit the E7 window to the last 4 hours. The heaters are generally fully charged after 3 hours. So that is 4.5 kW x 3 hours = 13.5 kWh.day-1 13.5 kWh.day-1 / 48 m2 = 0.28 kWh.m-2.day-1 0.28 kWh.m-2.day-1 / 24 hours = 0.0117 kW.m-2 0.0117 kW.m-2 / 1000 = 12 W.

I may just take a chance and get the ones that work on an Arduino, can get a couple of them delivered for under a tenner. Cheers anyway.

If you could and see if they work with an RPi, I then may get some as part of my Silly Sunday Experiment, which is now over a year old.

There is a little truth in that, and it does depend on what sort of boiler is used. Water is easy to move about though, easier than air if you want control. This is a big problem. I am not so bothered about temperature per sec, but I hate draughts, unless they are warm ones. I grew up in the Far East, so got used to hot and very humid, then had a spell in Holland and Essex, so cold and dry. Then France and West Indies, so used to hot dry winds, and much prefer them. One of the best places to judge comfort temperature is workplaces, there are a few studies on these. The big advantage of studying in the workplace is that people are already mentally occupied with work and productivity is easy to measure. Though there have been some bad studies, on on light levels springs to mind. Because of this we have highly illuminated offices and badly illuminated factories.

Purely as an academic exercise, has anyone every rigged one of these up to a RPi: https://www.melexis.com/en/product/MLX90615/Digital-Plug-Play-Infrared-Thermometer-Ultra-Small-TO-Can# They do a few different ones, including an IC2 one for about 3 quid.

For little things I bought these. https://www.ebay.co.uk/itm/7-in-1-4-30V-LCD-USB-Current-Voltage-Energy-Detector-Power-Capacity-Tester-Meter/273639126870

Well come the school summer holidays you will be able to start. Then you have, apart from 6 good weeks in September and October, 8 months to do them. When I moved into my house, the first week was really sunny, then it rained, every day, for 66 days.

Just as an aside, when I first started monitoring energy, I used an old desktop computer, it was drawing about 200W. I have some little USB energy monitors now, so shall plug on in and see what my Raspberry Pi Zero is drawing. It is reading 7 1Wire temp sensors every minute and logging the data. Seems to be about 0.55W (4.9V and 0.2A). If someone reminds me, I shall look at the Wh reading next week to get a better idea of what is happening. 12:15 PM 14/07/2019

I had a fridge that was consistently freezing stuff. Within a year it was running constantly but not cooling. I picked the extra electrical usage up on my energy monitor, so was only 3 days of wasted electricity and milk. So could be something as simple as a refrigerant gas leak. Might be worth putting a temp sensor on the back of the fridge (or where it dispels the energy) and seeing what is happening there. I noticed, in hindsight, that it was not warm.

@joe90 says he is 90% finished, so 90% left to go.