SteamyTea

Did you take that picture at my local Wyvale, or a special trip out to see the chavs in Essex?

Said be wanted me to dwell in his bottom.

When designing anything, the big decisions have to be made first. So in the case of a house, decide how much energy you want it to use, and when it is used. This is where Net Zero becomes a bit confusing, a lot of houses can be energy neutral, but you may still be importing 10 MWh in the winter, while exporting 15 MWh during the rest of the year. Be careful how you measure the energy usage, a kWh.m-2.year-1 metric does not actually tell you a lot. Much better to say 'I want it to use no more than 1 MWh for heating in a year. That then opens the next question as to where that is primary energy or delivered energy. This is where the technology starts to come into play. Different technologies have very different efficiencies: don't believe the manufacturers claims. CO2 emissions are also important, to keep them low you only have one choice, electrification. Generation is getting cleaner every year. If that is the route chosen, then PV is a must. This will set your roof design and house orientation (to the sun). Ideally you want to have no shading and possible multiple angles to spread the power delivery throughout the day and the seasons. So now you know how the roof will look, and how the house is located on your plot, the details can start. Those details may include location of waste treatment plants, water boreholes, connection to existing services, road access and parking, views and landscaping. Get a feel for that, and you are now into more details such as room layouts and location. Too may people start with the internal layout and hope it fits their plot. Seen a bungalow near me that has a lovely floor to roof sliding door, the view is a stone wall, less than 3 meters away. Then they put the garage in front of the kitchen window, but left enough view so that passing car's headlights shine into the bedroom. Was on the market for years; I assume they sold it to a blind person. When it comes to building a low energy energy home, it is all down to detail, both architectural and engineering. In reality, architects are just trying to hide good engineering details. There is no myths in what is needed to create a house to passive standards, anyone could do it with a spreadsheet and a book of material properties. The architects job is to make a properly sized widow and door fit into a 300mm thick wall. If the only way to control solar gain is to add blinds and shades, the initial engineering has gone wrong. Review it. Good engineering practice is what makes a low energy home, not bolt on afterthoughts that are only useful for 15 days a year. And don't get stuck on building materials, there is nothing wrong with a combination of masonry, timber and steel. They just have to be interfaced correctly. So, get a good structural engineer, a good understanding of building physics and a builder that you can trust and is willing to learn or at least does as they are told, then get the architect to make it look acceptable. Too often it is done the other way around.

It may be useful when doing a room by room heat loss calculation for sizing heating/cooling systems. k = W.m-1.K-1 [thermal conductivity] R = L / W.m-1.K-1 where L is thickness [thermal resistance] U = 1 / R = W.m-2.K-1 [thermal transmittance]

I have had about 4 handfuls of edible runners of mine. I chop then up and eat them raw in a salad. Not many left now.

Won't that be a very short lived thing. Vehicles battery chemistry is changing to make recycling much easier. Once a standard chemistry is agreed on, then there will not be any end of life vehicle batteries. If you have space, worth looking at lead acid and nickel iron. Hydrogen can also be produced from NiFe batteries once fully charged, but that is only for people that think hydrogen is worth pissing their pants for.

Because you have to plumb them to outside air or they just become heaters.

The Mini does only have a net 28.9 kWh battery. Which is 3 hours 12 minutes at 7.2 kW. https://www.mini.co.uk/en_GB/home/range/more-mini-electric/mini-electric-tech-specs.html Just about enough to get to other side of Exeter.

I am after an enclosure like that, better get on eBay.

There is so much there to unpack. And it is all wrong.

Either would probably do. But safer to assume a rate of 18p/kWh. One thing this latest energy crisis has shown us is that the 'challenger' energy companies, that perpetuated the myth about being ripped off, where talking bollocks. Hard to see how, Evan at £40/MWh wholesale, they could deliver at £120/MWh retail, to domestic customers. I would be very wary of signing up to Octopus, their prices seem too good to be true, so probably are. Market share and profitability are separate things.

Or, in a year or two reduce again. I don't think energy prices are a new normal. I would cost out at 18p/kWh. CfD prices for new RE generation are ~£35MWh.

@Radian As our electronical expert, how easy would it be to hack a cheap timer, like I linked to above, to add a ESPxxxx so that remote control is also possible. Thinking simple override for times of inconsiderate guests/children, or excess PV production.

If the volume of air in a building has a mass of 1 tonne, is changed 5 times an hour (typical ACH for a new build) and the temperature difference is 12K. Then that is 150 kWh a year. Don't sound much, but old houses leak at a greater rate and the delta T is for my house in mild Cornwall. My small house has a volume of 160 m³, so a mass of 200 kg. So 30 kWh/year. 6 quids worth of E7 electrons. Still going to improve it though.

Kelvin x angular frequency x hour

Welcome Get to grips with the insulation and airtightness. Stop those draughts (or is it is drafts). Read up on here about ventilation. Find out how your current heating system works. There could be energy savings to be made there (putting my old mates heating into ECO mode helped a lot). The rest is DIY. First room I did cost me about a £1000 to do back in the 1980s, had to buy loads of tools. After that it got cheaper. I even managed to renovate my back door last week, Got the twist out and it now closes against the frame, 3 quid draught excluder keeps the wind out.

So do I, much quicker if you put the right amount of water in. How so, an induction hob is more efficient. This years usage Last weeks usage. And the percentage of time that I draw no power at all, I think this is the real secret.

It's watts. Can cut that out with a £2 washing line. That is about what it uses to keep the 'systems' going, without actually going anywhere.

It is. Posted up some science GCSE papers a while back, was quite a lot of relevant questions in it.

@MikeSharp01 How you getting on with making a ESP based pulse logger?

Been there, done it, got the T-Shirt. A price shock really brings the point home. The main problem is that many people will blame externalities i.e. VAT, Green Taxes, overseas war, but make no attempt to actually change anything that they have some control over. An old girlfriend of mine runs a 2 kW fan heater all day in her living room, which is a good 1/3rd of the area of her house. She has gas central heating, TRV on all the radiators, but has convinced herself that it costs more to turn the central heating on. Her BiL is a plumber and gas fitter, she has worked with him, on and off, for many years. In her mind, the problem is the housing association, not her choices. She is (expletive deleted)ing mental though.

And then get it wrong.

Totally and unnecessary, the current higher prices is enough. Sometimes the stick is much better than the carrot.

" I think in about two years’ time we won’t need to heat the house at all,’ says Andrew." Who is going to call him and ask how it is working out. What village in Buckinghamshire was it?

https://www.boxabl.com/