SteamyTea

Welcome. A few years back now I had a lodger who had a stroke. While she could walk reasonably well, the foot dragging was a problem, she could easily trip up. So any door thresholds need to be eliminated. She had no real use of her right arm, and limited use of the left one. This caused problems with things like taps and controls on things like cookers. Also made door locking difficult. For a laugh one day, I tried to do everything just using my left hand. Gave up after 20 minutes as I could not roll a fag. Oh, and depending on which side is more able, if there is a difference, then the bog roll holder position can make a huge difference. Try and design everything so it can be accessed easily from both sides. And doors that can slide both ways are much better than normal fixed hinges doors, eventhough they are horribly noisy.

Whoops, it was late. I got G wrong, had it as 9.18. That should be OK then. I seem to remember putting something quite light onto some polystyrene and it sunk into it, pay have been EXP though.

If you know the material the element is made from, and the mass, you can work out how fast it will heat up for a given energy input. That may seem an odd way to calculate it, and you need to take thermal losses from the surround fluid into account, but should work. Alternatively, get an element stick it in a bucket of water, and do some timed test (my preferred method), then model from the data.

Mass [kg] is the amount of stuff in a material, it is not the weight that is affected by gravity. Force is mass times acceleration. The unit is the newton [N] Area [m2] is what it is, the length times the width, or pi.r2 or the integral of a curve, which is just the area under a line on a chart. So taking a mass of 1 kg, and acted on by Earth gravity, 9.81 m.s-2 over an area of 1 m2 1 [kg] X 9.81 [m.s-2] / l [m2] = 9.81 N/m2 So the 400 kg window sitting on a strip 4.2 m long and 0.1 m wide: 400 [kg] X 9.81 [m.s-2] / (4.2 [m] X 0.1 [m]) = 8743 N/m2 8743 [N/m2] /1000 = 8.743 kN/m2 N/m2 is often written as N.m-2 and is a pressure, in derived SI units, pressure is also known as a pascal [Pa]. 1 N.m-2 = 1 Pa With a bit more arithmetic trickery, it can also be expressed as 1 J.m-3 which is energy density. For more about the pascal: https://en.wikipedia.org/wiki/Pascal_(unit) Usual disclaimer, it is late and I have had another record breaking night feeding people. Is EPS a true solid, or can it flow over time as the air inside it is compressible?

Just done a quick calculation of my space heating as a percentage of all my energy usage. Space heating, for the year 2018 was 35% of my total usage. Total usage was 3,786 kWh for the year. 78% of my total usage was on E7.

I may have to get a few SSRs to play with. All I really want to do is switch my storage heaters on at different times, depending on the expected outside temperature. Just glorifying what I already do with my extra timers.

This is something I would like to know more about. It really should not be hard to design something that only the owner has access to. 30+ years ago, I was chatting to an software engineer and he said there was a system/protocol for making sure that software did what you wanted, without surprises. Seems something like that is needed now, any idea what he was on about (he was Belfast Irish, so he may have said something very different).

I must have about a 1000 of them in my chips box! really useful little bugger. Is it worth getting some so that I can connect my collection of RPi's to other things like an SSR. I have, so far, shied away from playing with 230V stuff. It does not scare me, just that I have not wanted to smoke any of my Pi's.

How about the simple 'Jamaican Joint', can grow your own in a planter.

What figures? I think you get kW and kWh confused. Or, if you prefer your own units

Yes, and mine, just. As I use about 1 kWh/day peak, the rest is off peak, which works out at about 85% of my total usage and considering, in 32 years my maintenance amounts to 1 immersion element (changed cylinder, but that would need changing regardless). Any heating system can be designed to cope with any temperature differences, so a bit of an irrelevance there. If you are still under the impression that even basic storage heaters are useless in all circumstances, then you are very misguided.

They enjoy the challenge of getting a flat roof watertight. Better off asking a boat builder to design one than an architect.

As there is less than 0.5p/kWh between off peak electricity (does depend on contract) and LPG. Why would anyone bother with LPG. I think it is just selling an old home heating model that is now superseded.

I remember the name, but nothing else. Many ASHP get rebranded, so there may be some in the UK, have a hunt on Alibaba and see what looks similar to what is available in the UK.

This is not new technology, prices in the UK may drop though. It is worth looking at CO2 heat pumps and the older gases are being dropped. This may affect long term servicing.

3 dissolved companies in 6 years for one of the directors. So no problem with the 1 year warranty then.

Can we start something in 'Boffins Corner' about this.

Because we are trying to do it with lower thermal losses, different energy inputs, consistent and reliable outputs, at known quantities, and lowest capital expenditure. Why I like vented system heated by a simple electrical element.

12 cans of Heinz Cream of Tomato Soup is £5.50 at my local Tesco. Like ketchup and baked beans, accept no other than Heinz.

Spiders go looking for water/moisture, or a mate. That is about if for their lives, apart from eating.

Just to highlight the variation of 'normal days'. The charts below all have the same external air mean temperature, within 0.1°C. I shall restate, this is not modelling a house.

I have been running an experiment for over a year now, just three boxes, exposed to the weather, with the same volume of different masses in them. This does not model a house, but shows that during cold spells, there is effectively no difference. Hot spells are a bit different. Mean temperature days are so variable that it is hard to draw a conclusion from temperature differences alone. Below are the coldest day and the hottest day charts. Lots of variation on the hottest day.

I haven't. I did think of getting one, as @JSHarrissent me a link to a Panasonic one that was pretty cheap. But when I sat down and worked it all out, I decided that I would stick with my storage heater for a little longer. Storage heaters are just so reliable and I only need them for 6 to 10 weeks of the year usually. Some years I have just used a £10 fan heater. The only thing with an airthight house is that if you go away for a few weeks and leave the heating off, damp can become a problem. I fancy fitting MVHR, so that would sort the problem out.

Sooner or later you will be.

Probably get away with half of that. If you can get some local weather data, you can see how often it will not supply all your space heating needs. The MCS rules is that a heat pump needs to be able to supply 99% of all heat load. It i a reasonable rule to work to as it builds in oversizing, which improves the CoP. Thing is about using an ASHP for space heating only, is that it may only be needed for 3 or 4 months of the year (though Kent has a cold wind), so may be worth considering using to to heat water during the other times of the year. Just needs more detailed modeling.