SteamyTea

Use the hotspot built into most phones. All by 'communications' come via my phone wifi.

Think they just learn to live with it. Never seemed to remember it was a problem when we lived in France, think we had a 10A supply, but cant really remember, it was 40 years ago and I was more interested in the neighbour.

Worth remembering that this are sometimes on timers. I would have to split my supply as I am on E7, not hard, but worth remembering. We were discussing the resent power cuts (BiL's parents had no power for 2 days). I said I use my camping stove, BiL said that was what his parents do. My Mother croaked up that there is a stove in the garage, there is, and a full gas bottle. The 1960s have a lot to answer for.

And you get an Atkinson cycle engine, which I think is the most efference gasoline ICE currently available. I like the idea of of just running an inverter off a car for emergencies. Maybe a leisure battery in parallel with the car one, but 'in the shed with the inverter'. Can be trickle charged as well. There is a 130 Ah on on ebay for 77 quid. Say you draw 50A for one hour, 600W, that would be the same as burning 1/4 of a litre of gasoline. Or about 35p worth. The equivalent grid electricity would be 15p. I would hope a leisure battery would do 2500 discharge/recharge at that level. The inverter is a bit more expensive. A pure sine wave one (which is what you need) will be about £160 for a 2.5 kW, 5 kW peak one So about £300 to sort something out that can be emergency charged from a car. Pretty good considering that you can easily add an extra battery.

Generally yes, if everything else is kept in proportion. The main thing with heat pumps, like cars, is to not use them at maximum capacity too often.

Can you copy and save all the material, then we can all have a go.

Eh ... 0.25! 0.288 kWh.day-1 But probably idling some of that.

1992 the format was released. Some of those old, grainy, artefact edged, colour corrupted images will be considered charming one day, just like sepia pictures are.

About time. If only people did not want to send multi meg pictures of their privates to each other, we could have a much faster internet. when I send a picture from my phone, by default, it send the full size image, that then gets viewed on a tiny screen. 30k would be ample, just like it was back in 1998.

They do not show the thermal conductivity, but it could be estimated from the data sheet. It has a density of 30-33 kg.m3 and is made from polyurethane. This one has a Tog rating of 0.3 A Tog (comes from the word for clothing, Toga)1 TOG = 0.1 m2.K.W-2. So at 0.0018m thick 0.0018 [m] / 0.9 [ W.m-1.K-1] = 0.002 [R = m2.K.W-1] 1 / 0.002 [R] = 500 [U = W.m-2.K-1] It should really be called a thermal conductor, not an insulator, but it is very thin.

I can see a misselling scandal coming.

Are these readily available, or a shield? Can't these also be just as effective, if made from to tin foil, and placed on head, like a hat. But this is the problem. PM 2.5s and 10s are smaller than a visible gap. Shall see if I can find the report about indoor air quality when I get home (and if I remember). Always struck me as odd, like getting a kettle, but no lid. But they are selling a feature, not a function in reality.

We can thank Isaac Newton for that.

Need to throw in system size as well. There is a big difference in suppling, say 55°C water, from a 5 kW unit and a 15 kW unit, regardless of weather.

Not any more. I miss it sometimes, but generally I grew to hate it. Was not the students, was the piss poor management.

Trouble is, unless you only need a handful of kWhs/day, you are into thermal store territory. Also, if you could rely on a 5p/kWh (equivalent) tariff long term, just fit a resistance heater/s into a large store.

Probably been thought of, and as it is not a main stream, well published feature, probably just not worth it. Easy and quick to take, what may be just half a kWh (about 10p), and pump it around till the unit drips.

Yes, basically means junking all the existing control system. May be easier to make it work on a non inverter one. I have often wondered how hard it would be to put a speed controller on the fan, I am not sure how much difference it would actually make. One of those 'retirement project'.

Then maybe the idea Joe, Dave and myself had could be worth a revisit. Should only need three Temp and RH sensors, external temp/RH, heat exchanger temp, and after heat exchanger temp/RH. When I was heat exchanger, I mean the radiator that the air gets blown though. Then a dew point predication algorithm that has a built in offset i.e. 3% above dewpoint, or 1 K above dew point, that turns the refrigerant pump off, but keeps the fan going to blow out moisture as it would not be 100% perfect. Then after a set time, it turns it all back on again.

I think the problem is, they do not frost up enough to have to worry about it. It is only us that want to extract the last 2% efficiency out of them.

But you are still using DHW, which is possibly your largest, continuous draw on power. It was an exceptionally cold and damp spell last year mind. I suspect the air was dryer this time as it was a North East wind, not a North West one.

Yes, it needs to happen a proper amount before frosting, not as it happens, that is then too late. Do you remember if we discussed it here, it on eBuild, I can't be bothered to look.

@joe90 and myself discussed this at length a few years back. We wondered if there was a way to sense the conditions that would cause frosting i.e RH and temperatures, then stop the ASHP for a set time i.e. half an hour. But as Joe90 found out it took 4 years before his ASHP frosted up last winter. Has it done it again in the last few days @joe90, I am still up country were it snows and freezes.

This topic has got me thinking a about having a hot buffer. Generally, the day tend to start cooler than they finish, e.g. the first 3 hours are, on average cooler than the last 3 hours. There are obvious exception to this i.e. a warm weather front moving in. Now if you start with a buffer that is at the slab temperature, pump some energy in until it gets to maximum operating temperature, then start to reheat the slab, while at the same time still putting energy into the buffer when needed, you will end the day with a buffer hotter than it needs to be. So maybe the answer is to stop adding energy to the buffer at set time, and just let the slab draw what it can. This could be made very sophisticated with rate of change comparators, but I think maybe a simple thermal lockout is all that is needed i.e. @7PM if buffer is at max temp, stop adding heat to it, if @7PM buffer is not at max temp, reheat for 30 minutes, then check again.

Or use supplientary heating for those extreme days.