SteamyTea

Genetics. Kids generally take the average height of their parents. Always tease my tall mates about their eldest being the mean height between myself and his wife. It is great when looks are exchanged and the conversation dies.

No, just (expletive deleted)ing short.

A really strong light will make your pupils like pinholes. That gives your vision a greater depth of field. It is really quite amazing that we can see in such low light levels, less than a W.m-2, and also in extremely bright light levels, greater than 1000 W.m2. Imagine having a heart that could do that, pumps around a little blood at rest, then 1000 times more when we are running. The human body should not work at all.

This is the whole point. The time it takes to cool is governed by the thermal conductivity, not the heat capacity. When in a steady state, the temperature of the mid point of the wall will be the mean temperature of the wall i.e. 10°C for an internal temperature of 20°C and an external temperature of 0°C. This has the effect of halving the stored energy in the wall. Because of the high thermal conductivity of stone, as the energy escapes to the environment, that 10°C point moves inwards, reducing the stored energy even more as heat only moved from hotter to colder. It effectively reduces the thickness of the wall, so what energy there is stored, is released to the room faster. It follows the Cooling Law, which is an exponential decay that is proportional to temperature differences. It is this proportionality that often causes confusion. It is not just the temperature difference between the inside and outside face of the wall, it is also to do with the temperature gradient inside the wall. If you really want to stabilise temperature, get an oversize MVHR unit and scavenge the energy out of the air, easier and more controllable.

My intuitive feeling is that separate HPs for Space and Water heating. They are different things, at different times and at different temperatures. My thinking is that you can get a small, but better, modulating one for space heating and a non modulating one for water heating. The reasons being is that weather effects both the HPs performance and the house heating load, but water heating is generally quite fixed in the amount of energy needed. So you can find HPs that better suit the two separate tasks, rather than compromise. And you could divert, via a buffer tank the DHW HP to space heating during exceptionally cold spells. But if it is worth it financially, I am not so sure.

If you have a buffer fitted, would there be any advantage in adding a low loss header, and visa versa? A buffer is a simple, cheap and easy to understand bit of kit, I would have thought it was one, or the other, but both is, if correctly sized, unnecessary.

Well that is wat all this debating is about. Built two equally well insulated cartoon house out of stone and timber, ventilation rates identical, and input the same energy to warm them, and you will not see a difference. This is what Physics tells us. Now if you build a stone wall, of normal dimensions i.e. 0.12 m thick, in the stone house and the timber house, you will see no difference. But if you built a timber wall in the timber house, you may see a slight variation, probably too small to notice. This is an interesting topic, skewed greatly by the local build types, but the Physics are the same. If I get time later (feeding my Mother at the moment and then exercises/looking up tax information) I shall sketch up some scenarios to highlight the problems in calculation all this (there are a couple of different ways to calculate it all, the energy model and the power model). No promises though.

Yes, but that is more to do with the energy input and the absorption. If you pump 800 W.m-2 into something that absorbs 95% of all the energy hitting it, it is going to get hot. Very different climates, why most of the studies are done in cloudless places. Go to undeveloped equatorial regions i.e. rain forests and the building style is very different. It is a balance, and non linear, between the heat capacity, shape, thermal conductivity, area exposed to energy inputs and outputs, it is not as simple as just mass. This is why there are no units for 'thermal mass'. Granite has a thermal conductivity of between 1.7 and 4 W.m-1.K-1 so yes, it does slow thermal transfer. But then Oak has a conductivity of 0.16 W.m-1.K-1. So it slows at least 10 times more. So even if, for the same raise in temperature stone stored the same amount of energy per unit mas or volume, which it does not, it also looses to the semi infinite heat sink that is the environment at a faster rate, leaving very little energy left to be transferred to the interior. Quite simply, if just adding mass to a building stabilised the temperature, we would all have been doing it for millennia. Part of the reasons that in the UK we think that adding mass helps is that we have an odd climate for our geographic location, stick the UK 1000km East and we would not be building in the same method. Find a low lying island 1000 km West and thing would be different again. There are also historic reasons that the UK likes 'brick', some go back 1800 years, other just 80.

Temperature is not energy.

That implies that the maximum temperature does not exceed 27°C, not that the mean temperature, over the whole wooded area, is 27°C.

That becomes a bit tricky to work out as it will depend on many things i.e ∆T, current ventilation rates, solar gain, modulating state of boiler/HP. Best way to test it is to close all windows, vents, put MVHR on low setting, boiler/HP on full/boost and watch the meter and thermometers. But don it on a still night to isolate those variables.

How did you account for evaporation losses if the water? One problem with storing energy in water is that the min and max temperatures are limited. Rocks stay solid over a much greater temperature range. Why storage heaters work. Harder to shift rocks about though, water is easy to pipe and pump. The only good experiments are carefully designed ones to test just one aspect of the material properties, and are repeatable by just about anyone with access to the same equipment.

Boreholes will perform better as the temperature is more stable. Trenched pipework can freeze the ground and this reduces power transfer, this is much less likely to happen with a borehole. There may also be a lot more free flowing ground water deeper down.

Concrete SHC 0.8 kJ.kg-1.K-1 Density 2700 kg.m-3 Heat Capacity 2.16 MJ.m-3 Liquid Water SHC 4.18 kJ.kg-1.K-1 Density 1000 kg.m-3 Heat Capacity 4.18 MJ.m-3

Can the type of lights/controllers you are using on the other circuits be sending a 'spike' down the line that is affecting the controllers. Some people pay extra to get 'remote control' of lighting circuits. Usually done over the interweb, but not sure why.

Or water source, get a good CoP from them, as I keep telling the morons are the Jubilee pool who spend over a million doing a geothermal project that failed. They then put in a WSHP. They could have just used a couple and drawn energy from the Atlantic.

Or not. Any store needs direct heating. Relying on natural inputs basically means you get cooling. No one has ever built a large, unheated basement and said 'wow, it is always warmer in here than the house' Others disagree, but it is what I studied at university and I am happy to stick by my findings. If you are considering batteries, may as well add a heat pump, for the costs of 4 kWh of batteries you can get 5 kW of heating.

Be about 30 modules, so 10 kWp. So not particular large. I quickly ran though my location and one near Aberdeen, used 4% as the interest rate, £800/kWp installed price, came out that the levelized costs was 0.046p/kWh and 0.065p/kWh respectively. That was for optimised systems.

Run your best estimate of usage though PVGIS

Is that St. Awful Brewery's New Year offering to go with Big Job, Odd Job, Proper Job and Blow Job, or was that last one just the name of the waitress in the Harbour Inn, Porthleven (actually has a fishing boat named after her).

What is the problem. Veg will grow well with all that blood and bone meal.

Would it be a temperature self regulating type?

That is not so bad. If they were in Chinglish it would be worse. Or IKEA could have written them.

Called the learning curve.

I will do that next month. It won't be what you want, or need, and probably won't perform very well. But I will make £3k out of it. Or They are doing it to comply with ECO rules/targets and will only install them in places that are suitable, and may be very low quality installations.