SteamyTea

As does CT1

I have kept out of this as I know nothing about it. But, as I like voicing an opinion. If the walls are 2.7m high, how much room is there at the bottom, the width and length. Could you make a slide? Every degree from vertical reduces the downward force. At 30° it will have 87% of the apparent mass, 45° 71% and if you can get to 60°, then half the apparent mass.

That nicely sidesteps the particulates that are in the house that the wood burner is installed in.

Can't do anything about that, except develop a wireless solution, like I currently use. So when your import meter is constantly lit, and your export meter is flashing, you know that you are self generating and exporting. When you are importing and generating, both will flash. Sound like a third meter, with a CT clamp may be needed. Many years ago I rigged up two meters with 7 clamps to work out the flows on a 3 phase PV system, matched the usage, imports and exports very well. As Damon says, not perfect, but pretty good.

Well my CurrentCost, coupled to an RPI is good, shame they don't make them anymore. A few on eBay though. I have seen a project to make one that reads the LED pulses on a meter, that should cope with PV as you can put a sensor on each meter (I assume that the the LED still goes on permanently when exporting.

Probably only need to go up to 45°C, so should be a little higher. There is also a quirk when the external air temperature is between 0° and 7°C, the CoP can reduce. This is to do with frosting. On a really cold, but dry, day, the CoP can increase. Have you read the stuff on here, and over at the other place, about views on woodburning? Not a good thing.

And energy is too cheap to change habits/goods.

Why don't more people on here use an energy monitor and logger. Would take all the guesswork out if it.

As Dave says, bad design and execution are not a substitute for reality.

I had that problem. I cured it by putting sharp spikes in my flower pots. Made them from old slates. Works a treat, they shit in the neighbours garden now.

One of my sister's ex husbands has leukaemia, along with one of his brothers. He seems to have it all under control now and I don't think it is affecting his life anymore.

Right, yes. Why the outside of a building needs to be wrapped in a windproof barrier. It is also why adding excess mass does not aid temperature stability. There is enough mass in plasterboard and OSB for that.

Too true.

Not sure what you mean here. Shielding a house from the elements is a plus for stability, but may be a negative for overall energy usage. Stick a house on our western seaboard probably has the greatest benefits overall. It is why I get away with low energy usage, even though I am 200 metres ASL, when I get strong winds, they are warm. And when the temperatures are high, with little wind, I get cloud (last two days have been misty and wet here).

Car Sauna time.

I thought that my hayfever was bad this year, had to take 3 days off work (though I could have gone in after a day off), first days I have had off in over 25 years. Makes me a pussy compared to what you have.

I am not so sure. Looking at my data, when there is a very small, or very large difference between internal and external temperatures, the instability is greatest. Exactly what one is trying to avoid. Some of this will be down to the low number of samples, 322 for the bottom two temperatures, 43 for the top two, but 52,922 for the ones in the middle. The rest will be down solar gain and heating/ventilation. I am of the opinion that it is almost impossible to design a normal house that can take advantage of time shifting the thermal loads. This is mainly a UK problem as we are above 50° North, which means we have large change in solar gain throughout the year. We are also surrounded by a warm ocean on one side, and a cold sea on the other side and are windy and cloudy. It is also worth remembering that at low temperature difference, there is little capacity to store excess energy, the energy difference is the driver. Then at high differences, losses are greater as there is more energy to disperse. That is why cooling and heating does not follow a straight line, or even a simple sinusoidal curve. Not even solar power follows a sinusoidal curve (it is the sum of at least 4 curves, and then a random element for clouds, Fourier showed us this). I just added a trend line to my chart, the equation is y = -4E+08x - 2E+10. So basically flat. I expect the second part the, -2E+10, to get closer to zero as the year progress, though this is weather dependant, and weather is fickle.

May be a sign that your diabetes is all over the place, or an embolism. Had a regular customer in tonight, got chatting and found out she has tinnitus quite badly. I wonder how common it is? And how many people never bother to get it checked out.

Worth getting it checked out.

Does it match you heartbeat. My tinnitus is a high pitch squeal, sometimes quiet, sometimes loud. Loud at the moment as I am thinking about it. Some people get quite distressed about it, but having had it since my mid 20s, I just accept it. Does make very quiet nights a bit interesting. Usually just put the radio on.

If you genuinely have tinnitus, you need to be turning the volume down, not up.

Have sorted and cleaned up this years temperature data, interesting result. As a house cannot be placed into a lab, one can only work with the prevailing conditions. This can be described as 'normal usage'. What seems to be happening is that the decrement delay runs into the millions of hours, with the only times it is in the sub tens of hours is at the extremes. During the normal external temperature ranges of between 6°C and 18°C (this is Cornwall, so no big extremes), there is very little change in internal temperature , it just tracks external temperature (y = 0.2792x + 16.869, where y in internal temperature and x is external temperature). It increases by 0.28°C for every 1°C external temperature rise. Over the whole temperature range this year so far, it is only 0.34°C for each 1°C rise in external temperature. I suspect that most of this is down to the ventilation i.e. I close windows when it is cold, open them when it is hot, solar gain. I may have a look at night time temperatures later, and at extremes. This may give a fuller picture as it eliminates one element. Deaggregating is not an easy task as the signal to noise ratio is quite low, but I shall see what comes out. But basically my feeling is the adding additional mass to a building makes almost no difference to the thermal response times. This is more affected by ventilation, heating/cooling and solar gain. But to initially answer the question, does 2 hours difference actually make a difference, then no.

That is just the thermal inertia of the materials. Easy to work out as it is the product of the conductivity, density and the heat capacity. https://en.wikipedia.org/wiki/Thermal_effusivity

As 'decrement delay' is the time taken for a set temperature drop, knowing the starting points and the ending points are important. And the drop in temperature is only half the story, there will be a rise in temperature sometime, which in average, will need to balance out (or the temperature will always rise or fall). Then there are the measurement conditions i.e. energy forcing, are they positive or negative. This will make a huge seasonal difference i.e. what happens in the summer and winter can be very different. Even spring and autumn, which may have similar hours of daylight to your decrement time may well be very different. Taking my house, which I have long data sets for, I have a delay of 12 hours per -1K between midnight and 6 AM, 6 AM to 9 AM, it is 12 hours per +1K, 9 AM to 4 PM, it is stable, so infinite hours per 0K, a classic divide by zero, 4 PM to midnight it is 24 hours per -1K. So taking simple mean averages, it is 18 hours to cool by 1 K, but 12 hours to get back to the same energy level. These do not match, but one is in part darkness and the other full daylight, the 6 hours difference is due to solar forcing and my heating/ventilation system. Looking at the last week (01/08/20 to 08/08/20) there is no noticeable difference in times, just higher means temperatures. Worth noting that, so far this year, the internal temperature range is still only 1K on an average of 21.6°C internal (this will drop to about 20°C for the full year) on a mean external temperature of 11.6°C (this may creep up to about 12°C for the full year, autumn is warmer than spring). The mean temperature difference, between internal and external, so far this year is 9.9°C. So a better way to measure temperature stability may be to look at internal temperature range for different external temperature ranges i.e how much does my house vary when the external temperature is 0°C, 1°C, 2°C etc. This would take a bit of analysis, but shall see if I can do it sometime.

sCoP and SPF are basically the same thing, just measured in a different way. The main thing is to get it sized correctly, which may mean it seems oversized. This is to stop the inbuilt immersion heating coming on and reduce the chances of the unit frosting up. Basically all you need to do is work out the different costs of running different systems.