SteamyTea

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.

No, pretty standard 1987 timber frame. Temperature is kept at a steady 20°C, plus or minus a degree. Heated by a couple of storage heaters (from 1987). It must have some, even a cardboard box has insulating properties. It would not be hard to set up a room for testing and comparing different heating systems. Just a case of putting in all the kit. would cost a bit, but that is the nature of developing new products. For two winters I experimented with just heating the house with a 1 kW fan heater rather than the storage heaters. It worked just as well, used the same amount of energy, but cost more as I was using E7 and running the fan heater during the day. I did this to see if it was worth me changing my heating system. Decided it wasn't. That is the beauty of data collection. It is easy and cheap to collect electrical power and temperature data these days.

Scratching my head a bit here. That works out at 60W/m-2 I heat my house with 12W.m-2 I think you may be getting installed capacity and mean power delivery a bit muddled. This also seems a bit odd and adds to my suspicions.

May be worth remembering what Richard Feynman has to say about this sort of thing:

Think it is more a case of comparing it to E7/E10 heating systems, which are very controllable now.

I am not sure that is strictly true. We have capillaries that carry blood to our skin surface, as well as sweat glands, to control kin temperature. Also, there are many organs that are that close to out skin surface (unless one is covered in blubber. Just been to Redruth and people look like seal pups there), so if FIR really can penetrate over an inch, then we would not be able to stand outside for very long. Also, the thermal conductivity of water, which is around 0.6W.m-1.K-1, or near enough the same as brick, plaster, soil, is not really relevant when it comes to efficiency. Thermal Inertia, which is what I think you are on about, is the product of specific heat capacity, density and conductivity, also plays no part in working out the efficiency in this scenario. If it was important, then efficiency ratio calculations would be quite complicated. Now who said about a microwave and a convection oven. There really is not much difference. It does depend on the shape of what is being cooked, but they both work by thermal conduction. Microwaves don't really cook 'from the inside'. They just jiggle water molecules effectively, starting off a convection process.

Have you read all this: http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=125&page=1#Item_0 Makes @onoff bathroom an afternoon project

Not that multifoil insulation sellers would do anything like that.

I was waiting for this. What you seem to be saying here is that you can be in a room that has cold air in it, but as long as you are bathed in some far infrared radiation, you won't feel cold. This is not how one measures efficiency. I can make my car more fuel efficient, over a set period of time, by not driving it much. Not really the point though is it. One possible problem with having a house that is colder than necessary, is that condensation can be an issue. I hope you have done a risk assessment on this aspect.