SteamyTea

So did the Dutch, a few of the places we lived in had wall carpets, even in the Dutch East Indies (Indonesia).

Read your meter every time you get in, or when you leave, for a few days, see how much energy you are using. There will be 3 readings on it, Total [t], Day [1] and Night [2]. We can probably estimate DHW usage quite well. Does seem like your place is under insulated.

My larger ones does that, 2 to 3°C difference between the centre and edges, when measured on the top of the front face.

They are a bit bigger than my living room one, but about the same input. 3.4 [kW] x 7 [h] = 23.8 kWh If that stored energy is released evenly over the next 17 hours, that is a power output of 1.4 kW, which is not that high. As you have two of them, you will get double that, so 2.8 kW, which is about the same as a 3 kW fan heater would churn out. 36.5m2, so almost as large as my house (which is 48m2 over two floors). As you say, one heater is attached to an outside wall, not the best place for them. I moved mine to the party wall, but never actually bothered to measure the performance difference as I did it as soon as I moved in. They are easy enough to move. As your are in the frozen north, I suspect that they are undersized for a proper cold spell. I had a house in Aylesbury and during one exceptionally cold spell, the gas CH could not get the house warm and I had to get some electric heaters, as did my neighbours. One thing that can happen to SH is that they heat up to maximum before 7AM, then shit down and the output flap reopens (it closes when being charged up). It then starts to heat the rooms up but does not loose enough energy to have to recharge before the E7 window closes. This may mean you are loosing 2 hours of time shift. This can be caused by either a faulty input thermostat, the automatic output flap not responding to the charge period (it is a bimetalic strip that gets separately heated when they SH is charging up), or a stuck open output flap. You can sometimes hear the output flap slam shut (a good thing) but you don't hear them slam open. What I suspect is happening is that they are a bit on the small side for really cold weather, it is what usually happens. Do they work fine come April?

There is enough knowledge and skill on the is site to build a very good house. Just needs organising.

If you want low energy, then it will be a basic, 4 sided box. If you want 'eco' then it will be timber clad with grass on the roof.

14 quid each. Can I sell you some.

Really down to lack of use. Not many of us need to do basic algebra every day, so we forget the basics, then get confused when we try and do them. There is also the 'mental arithmetic' issue. Some people are very good at holding information in their heads and then retrieving it quickly and accurately (I am not one of them), this does not mean they cannot do arithmetic, just that they need to write down the appropriate numbers as they go along. Spreadsheets help a lot here. When a maths teacher puts up an equation on a board, then shows how it is calculated, they are not doing mental arithmetic, they have learnt how to do that example by rote, like an actor learning their lines. It does get a bit more complicated when indices are used, but there are rules that are easy enough to implement and if you use them often enough, they make life easy. If you don't do them often, you forget them. So the trick is to use algebra and indices as often as you can, and do the calculation with pencil and paper, then do the final bit (the actual numbers) with a calculator. You will generally, intuitively, know when something is not right, best thing to do then is start again. It took me over 20 years to get to grips with a text book example about calculating maximum volume possible for making a container, from a single flat sheet of material, using differentiation. I have never had to do that at work, but once I did it, it became a useful tool. I now know that it is possible to model this before it is made, even if I cannot, right at this moment, remember how to do it.

SHC of water is 4.18 kJ/kg.K Fusion is 334 kJ/kg Air pressure will make a difference, but basically, if you have are trying to get the air dry, it takes a lot of energy if the temperature is above 0.01°C

(kg.m²/s²)/s

Should be obvious to everyone that has been to school. Time = s Distance = m Mass = kg

Which seems to be happening now according to the news.

Possibly, but if you are buying shares, they value may be different.

I seem to remember from business studies that with an investment, you get your capital back as well as any interest or dividend payments. It may seem a minor thing, but that is why it could be a risky speculation, rather than an investment. There has been talk, for decades, about getting local communities to pay for local wind turbines or solar farms. These schemes usually involve a large developer selling a turbine to some sort of community interest company. It may be attached to planning as well.

Yes. Just a light-hearted quip about soft drugs and glue sniffing.

Glue it in place with Bostik

I find a joint after 3PM relaxing.

A virtually incompressible fluid will have less energy in it than a compressible one, for the same pressure. It is why pressure vessels are tested with oil.

I have this one. Really got no complaints about it at all. Just make sure only one person in it at a time. Not a strength issue, just that if there is a wobble, two people trying to correct it makes it worse. https://www.laddersandscaffoldtowers.co.uk/acatalog/Home-Master-DIY-Scaffold-Towers.html

https://forum.buildhub.org.uk/topic/30898-new-type-of-heat-pump-coming/#comment-458733

I think this is about the third thread about this HP. Bet it sinks without a trace.

That is an interesting reply. On today's broadcast, they were talking about the workplace economics of going green. I learn quite a bit, and I studied environmental economics, but from a western perspective. The two Ugandans on the course saw things very differently.

Then you will never know.

The way I understand it, it is not the voltage that is the issue, it is the isolation. 110V on site uses isolating transformers, there is no reason why it could not be a 230V isolating transformer. These have no physical connection between the primary and secondary windings. So if you touch either the nominal live, or neutral wires, they become grounded and at 0V (or very close to it), this zeros the power as power is VA. Just don't touch both at the same time.

It is interesting about the science and mathematics needed. It is taught at GCSE level. What is lacking is public understanding and interest. I tried to set up a course, couple of hours once a week for a term, about environmental issues. The CAM commented that she thought it would be about recycling and growing your own vegetables. To show how little has changed in 15 years, the BBC, this week, are running a show on the radio that highlights the mismatch between the science and the public understanding. Here is the link. https://www.bbc.co.uk/programmes/m001gk5d I suspect very few of you will listen to it though.