JohnMo

We have big overhangs over the windows which is great until mid afternoon and the the lower sun going down to west get in. The internal blinds work quite well, but not good enough. Will have a look at external blinds also, thanks

Or a dMEV fan, designed to run 24/7 at very low watt draw, so running costs should be low. Shop around and they can be picked up cheaply enough, greenwood, vent axia etc.

Think I would have shrunk some of the south/west facing windows, trouble is we have great views, seemed a shame to miss out on them.

Been told we need cooling in the lounge and possibly in the bedroom (about 10m away from lounge) for next year. So looking for advise So two options, as I see it. May be others? 1. Get a heat pump with cooling, run through the UFH, most expensive option. Not sure how good it is compared to aircon 2. A2A, least expensive option, but depending on how many units I need could be more expensive. Could run in heating mode also if required. Not sure how to size? Not keen on pulling house apart to fit something and wife not keen on external units (but may have to live with one) Have seen through wall aircon, but input vs output doesn't appear that good. Water cooled aircon, main water in and then to drain, seems a waste of water.

But perspex will look rubbish, unless it's thick, so it doesn't flop about in the wind. But it scratches easily, thick perspex is a similar cost to glass, last time I looked, a couple of years ago.

https://www.hse.gov.uk/healthservices/legionella.htm

Forgot mention, we had no PHPP modelling done or any consultants. Most building firms don't have a clue about airtightness or low energy building, nor most plumbers for heating system design.

I would rather work with, with being the important word, an architect I have a good relationship with. Teach yourself about thermal bridging, insulation continuity etc, same for airtightness principles. Formally review the architect drawings to ensure you have what you want, get him to change what's required. Be an active client, explain this to the architect from the outset, as most client are passive. Nothing is approved until it's approved by you. That's how I did my design. It may not suit you, if that's the case go to the architect you don't know, but with passivhaus design experience. Remember - Form factor is important, basically the closer the building is to cube the more efficient the insulation becomes. Our house is as far from a cube as you can get, if we insulated a cube to the same standard as we have, it would need no heating. But a cube building on our site would be wrong and look out of place. So we have heating.

Simple truth is to heat a set volume of water takes the same amount of energy plus a bit for heating coil efficiency loss) Heat loss will depend on how well insulated the cylinder is and how well the pipes coming of the cylinder are insulated. Some manufacturer will make it possible to heat a small part of the cylinder, so only a small percentage of the cylinder is heated, cutting down heating cost, but also water available to use. Great if you live alone and sometimes have a house full. But may not be much use for the normal family. Big surface area coil (more efficient and quicker reheat time) and thick insulation is best. Sized to suit your circumstances.

Surely that never happens 😜

That would be right! We're being ripped off like everyone else

Looked at Scotland's production profile, it has approx 10% of all production installed capacity as gas, the rest is renewables and nuclear. General average of 97% of electrical generation comes from a none CO2 source. Gas is pretty much only used as and when needed.

Nice, but well over budget. Or on budget in some other alternative reality, like some of these builds on TV tend to be.

I read Stiebel Eltron ASHP manual a while ago, it went in to exactly what the min flow and system volume you were to provide for their heat pump. If you could not provide both the flow and system volume you had to add a buffer to meet or exceed those requirements. Making the sizing or need of a buffer pretty easy. May be worth finding a Stiebel Eltron manual for size heat pump and see what it says.

You may be better running in weather compensation mode anyway, so it runs at very low flow temps, so get a better CoP. Run in day and overnight in set back mode (2-3 degrees lower temp), and normal mode when your home.

Is that 14 zone (thermostat with time control) or 14 UFH loops? If it's zones I would reduce to one upstairs and one downstairs. Use the thermostat as a limit stop, tune flow temp and rates to get room temp where you need them. I would say your flow temperature is set incorrectly. For cylinder heating (45-46 cylinder temperature) you would need a slightly high flow temp 50ish, otherwise your heat pump will struggle to get the cylinder up to temp and use needless energy. For UFH your flow temp should be no more than about 30.

None of options are easy. I want to install some more panels on a wall on the drive, no shading, but wife says no.

Your getting a CoP of less than two. I would be looking at flow temperature for UFH and hot water cylinder, you should be Getty a higher efficiency than you appear to be doing. Other things that effect efficiency Too many zones, cause short cycling To many many on/off cycling of heating timers and thermostats

You can also change the angle. Vertical mounted panels flattens the output curve, a more flat mounting position, decrease winter output in favour of summer production. Best idea is mess with tool linked to previously, to get a system that suits you and your available mounting positions.

Just size the array to suit your needs, make it smaller

Just use a normal string inverter but add Tigo optimisers to each panel.

I just purchased a lot of ultra signature composite decking planks, they come with a 25 year warranty, so hope I don't get an issue.

No to human, but the way we are going we kill our selves off. Cows yes. They could be banned, they emit loads of methane also

They only bothered with CO2 emissions reduction - blunt stick approach will do

Another way I found was (in US units) V= t(Qhsmin – Qloadmin)/500(delta T) V = minimum buffer tank volume (gallons) t = minimum heat source on time (minutes) Qhsmin = minimum stable heat output of heat source (Btu/hr) Qloadmin = minimum concurrent heating load when heat source is on (Btu/hr) ΔT = change in average tank temperature during minimum heat source on time (ºF)