SteamyTea

It is the smallest independent circuit in the system, not the compete system.

Not in my pots they won't. Got furry fungus on my potatoes though.

How about this one. Not read it myself, just a quick skim. Does talk about thermal mass though. https://www.irjet.net/archives/V8/i2/IRJET-V8I2307.pdf I think the problem with using timber shelves is that the grain needs to be pointing towards the heat source (sun). Books should be similar to cellulose insulation, a bit denser, with a higher volumetric heat capacity, but greater thermal conductivity as they have less air between the pages. I find that books, when stored badly, go mouldy. My first dissertation rotted away in my first house in 18 months. Shame as I was quite proud of it at the time. I once modelled this and then created an experiment. I used 15 W.m-2 and 25 W.m-2. There was very little rise in temperature at those low levels. Newton's ghost was hanging around I think, then Fourier came and gave me a kicking.

Why don't oil burners modulate. My car is a diesel, modulated extremely well.

Would you be interested in putting energy meters on both the ST and the DHW side of the PV. Chart the readings against your weather station. (the ST thermal meter need not be an expensive one, just something that logs the times it is running and the flow and return temperatures, a RPi job)

Like any water problem. How to remove the water faster than it collects. Just complicated by the amount of suspended solids in it, evaporation rates and frequency of rainfall.

When the USA decided to put a man on the moon, they did not know, in detail, how they would achieve it. So they made the big decisions first i.e. man on moon and return. Then looked at the next big decision, getting to orbit, why they used a 3 stage rocket, was all that was realistic at the time. Then the journey between Earth and Moon. Easy, a large enough container to live in. And so forth. What they did not do was get stuck on details like the size of windows and the colour of the bog, all that flushes out later. So make those big decisions now, write them down, amend if necessary, get an orderly list, then start to go into detail. Much of the detail can be changed easily. So How large is the house--> 1 or 2 storeys-->Number of rooms Running Costs--> very low or ordinary--> renewables energy or traditional Build Type--> quick to watertight or quick to completely finish And so on.

Could be. My seed was quite old, been in the useful draw for 2 or 3 years. Just got a timelspse package for my old kindle. Shall see if I can set it up overlooking the beauties.

Usual to send ones like that to a psychotherapist. Sprouted a lot faster than mine.

Just cost me £480 to have the mixer unit (actually the box in the loft) on my Mother's Aqualisa shower replaced. No real complaints as it is well over 20 years old (we are not quite sure when it was new). Simple control. Press button, it comes up to temperature, light stops flashing. Temperature is controlled by simply turning a dial. I assume the temperature has an upper limit for safety.

It is the same, really. With the sawdust and shavings being the inefficiency of the process. If you start with the plant growing, energy forces the chemical rearrangements. Then, when you saw and chisel, you are adding energy to break those chemical bonds, usually causing a rise in temperature (I bet you have touched a drill bit right after use). So rather than think of woodworking in a top down manner i.e. what saw blade is best, think if it from bottom up i.e. how strong are these bonds, do I need lots of small cuts, or fewer large cuts. Richard Feynman was once accused of not appreciating the beauty of nature, his reply was along the lines of: "I can see the beauty in a flower, just like everyone else. I can also see the beauty of how the cells are arranged, and the atoms that make those cells, and the equations that describe those atoms". Got to be better than just using a bigger hammer.

Just think of heating as a radiative model. Add energy to any material and electrons will be raised up an orbital level. Then, as the electrons drop down to the more stable position that they prefer to be in, a photon of light is produced. This photon can be thought of as pure energy. That photon will soon hit another electron, raising the energy, only for that energy to be released again. This goes on forever (or untill all electrons are at the lowest energy state). Sometimes there is not enough energy to move an electron up a level, but enough to twist, turn and unbalance the whole atom. This is how energy is stored. Some materials soon rearrange themselves, giving up that heat quickly, others take there time, so can store energy for longer. So like a game of snooker, bounce balls of each other, but just think that instead of the colours being worth more points, they are just different materials with different energy levels waiting to be released. What's hard about that.

Wrap the joint in composite plastic. A vacuum bagged and autoclaved wrap of carbon fibre should outlast most of us.

Sounds like you have normal condensation problems. Really a matter of how far you are willing to go to solve it. First things though, are there any problems with drains, downpipes, gutters, window sealing, roof, walls etc that may be allowing water into the house? Assuming there are not any, then it is a matter if controlling the ventilation. As a house can be thought of as a box, the less air that can escape it the better. The problem is, people breath out and sweat water vapour (about 2 kg a day each). If that water vapour is not removed, it will condense on the first surface it finds where the temperature is below the dew point temperature. This is usually windows, so quite visible. Thing is, not all the vapour will condense, some will work its way through floors and ceilings (generally via holes and gaps) where it can condense into timber joists, unnoticed. This is where the real problems start as rotting can happen. Old fashioned thinking was to allow cold, lower humidity air from outside to, in effect, carry the excess moisture away. Modern thinking is to contain the moisture laden air inside the building, then mechanically extract it. This is done with a vapour control layer, which is just a plastic sheet to keep the air in, an airtight bag if you like. Because it is airtight, and people are inside it, eventually the air needs replacing. This is why trickle vents were fitted to windows, and air bricks, now we fit fans, and some of those fans have heat recovery on them. So to sum up. Old method was to allow uncontrolled ventilation, haphazardly installed by the builder i.e. holes and gaps, so lots of air changes when windy, none when hot and sultry. New method is to have controlled ventilation which is at the correct rate to stop condensation and keep the air fresh. Simple really.

Not claiming 15⁰ is the minimum, but in the couple if flat roof installs we did, that is what I set the angle at. Both of them were easy to clean anyway. On the West (wet) side of the UK, setting modules flat has the benefit that in cloudy days they perform better than optimally angled modules. Only a small difference though.

I have played around with LISA and SolidWorks, but on here, it is usually a spreadsheet. The basics of thermal modelling are pretty simple, just areas, material conductivities and temperature gradients, plus ventilation. Where it starts to get complicated is where water vapour starts to condense, especially true when drying out a new building, or renovating an old one. The other thing people are interested in, is energy storage within the fabric of the building. This opens up a can of worms as some believe that adding more mass is better than lightweight structures where just the air is heated (or cooled). The waters get muddied when energy prices and CO2e are included. Solar Gain, which in most of the UK at least, has not been much of an issue, is starting to be thought about because of better insulated and airtight buildings, and Architects love of large windows. The usual mitigation method is to add blinds, reflective films or air conditioning. I usually find it easier to do a statistical model and then decide if there is a serious problem, or a very small problem. I would hardly want to pay out a few thousand to solve a problem that may only last a week, especially if it only happens every few years (had our very first extreme heat warning, where I am, 50°N, 5°W, ever last year, got to 26°C). Hardly a real problem.

I like the clock. Did you take the reflectivity and absorption of the glass into account, or just treat the window as an opening? You may find you are in great demand for thermal modelling.

Good stuff, just wait till @Adsibob reads this. Only GCSE stuff, just a case of learning the SI and SI derived units. At least you will be able to work out thermal inertia and hopefully explain it better than I have.

A few weeks back yes. Since then, not much rain. Today we had loads this morning, a proper SW amount.

I have been amazed about the lack of reports of modules coming off roofs. They do have a second line of defence in that the cables should stop them hitting the ground. I did see a ground mount system where just plain washers and nuts where used, thermal expansion and contraction and 'wind rattle' had loosened them. The installer thought that someone had undone them in advance of stealing then. But it wasn't. He went back the next day with Nylocs.

One of the problems with very shallow angles <15°, is dirt build up. Rainwater just starts to stick to the modules.

Do you mean this product, rather than any Medite product. https://mdfosb.com/en/products/medite-vent

Comes about from the MCS rules. If I remember correctly, 200mm from top and sides, 100mm from bottom. But may be more as the rules change. Wind and snow loading calculations should be done as well. Should be something on the MCS website.

Maybe something is introducing something that should not be there i.e. leaky gas boiler flue.

Going to follow this as I want to make my Mother a grab rail by her front door.