Radian

Your comment back in May stuck in my mind for some reason. I have no obvious explanation for it but recently I put the Triac dump box in our kitchen to exercise it with a 3kW load (the kettle). Yesterday I noticed some odd flickering of the activity LED showing short bursts of power being dumped when it shouldn't be. It was very obvious that it coincided with the washing machine doing a fast spin. At first I thought it might be throwing the power measurements but it wasn't. Looking at the logs it was just a massive amount of noise getting onto the AC. This was more than my analogue filtering could reject so it looked like the AC cycles had been 'tagged' for consumption. It should also have been rejected by the fact that the MQTT messaging didn't show any export going out into the Joule bucket but this revealed a silly bug I'd put into the code... the whole point of all this testing! I also realized I had way too much gain in the analogue path so dropped the filter Q from 20 to 4 and gain down to one. Still get a ~5V pulse corresponding to the 120kHz signal coming from across the house. I hadn't paid much attention to the fact it was clipping at this level before so there were unhelpful amounts of gain in the initial analogue design. Anyhow, it made me recall your early troubles. It's made me wonder if the kettle might be a useful destination for excess generation at certain times of the day...

I would think it's worth customising as much as possible, so the welded solution is good. Bearing in mind what @Dillsue mentioned you could also redo the bend to bring the cranked end closer to the tile above the bracket so reducing the leverage that will tend to push it down onto the face of the tile below (it looks to be around 40mm too long).

Right, so presumably you're going to enlarge or re drill the hole in the bottom section (the bit that screws to the joist) to bring the bracket down flat onto the tile?

Daft question: why have you got those spacers there (18mm?)

This almost sounds like he feels very sore about his initial offer of help being rejected and is acting out of spite. That would be odd but It may stem from a lack of communication over the moves you took to bring in other designers. Sometimes people build an inaccurate model of what they think another person is thinking and act entirely on that misconception. ...Ah, I see Jilly just got in ahead of me but yes we're thinking along the same lines.

You may have noticed that I'm a big fan of these! ~£12 for an energy monitor that talks over MQTT and can be turned on and off as well - just heaven. The only grumble is how hard those cases are to pull apart to reflash the chip. I think there might be a way to do it OTA but I like to eyeball the circuit before putting it into service. You never know what you might find inside them!

It was a lovely picture in its day but HD only. And the width of that bezel !!! The new one is a 65" Philips OLED (LG panel) but looks much more petite in the room.

Simples. The 16YO Panasonic 55" plasma sucked nigh-on 700W. The clue was in the 5 fans along the top edge. The phosphors were so degraded the brightness had to be maxed out all the time. The payback is a simple calc. of the energy saving of 600W for ~4 Hours per day (the new OLED is ~100W). The clincher in this deal (apart from the heavy discounting on this 2021 model) was Curry's current trade-in offer... they paid me £100 to take the 50kg Panasonic away 😀 I did shed a small tear as it was otherwise working perfectly. Your PDF was a fun read.

Probably, but then it's still a 25 YO compressor and I'm the extra gas load may just see off the bearings. I have a program of renewal underway now. Just put into place another energy saving exercise. This one will save us around 875kWh PA. Before: After: An upgrade that should pay for itself in 3 years. And it's way more glowy.

The compressor is 120W and is running almost 50% of the time. So around 525kWh PA or £160 at 30p/kWh and £260 at 50p if it comes to it. I was using the mean of those tariffs for the ROI estimates. I think the compressor is shot. It's been going for the best part of 25 years now.

I've got that price down to around £850 where the thing could pay for itself in 3 to 4 years (even less if we get to 50p/kWh) - whereas if I got another 3 to 4 years from the existing one then at EOL I then have to fork out for a new fridge while this new one would already be at break even point and should go on for another to 10 years or so. So no brainer really.

From the spec "Ultraviolet Transmittance of UV 11 %" Peak Solar irradiance is around 1kW/m2 You say your roof windows are 134cm X 98cm (1.3m2) and 134cm x 160cm (2.1m2) or around 3.4m2 in total. At 11% transmission this would equate to a heat source of no more than 380 Watts. Of course it will depend on the area facing the Sun at any given time. It doesn't sound like much but I have roughly half that area in my worst hot spot and it does push the temperature up by a few degrees. This is when all your insulation starts working against you!

Almost as cheap and possibly nearly as effective and maybe permanent solution is to apply a UV blocking film on the inside of the glass. Amazon have plenty to chose from for around £10-£20 a roll. With plain glass the short-wave UV in the sunlight gets through and is converted into longer wave IR when it hits interior surfaces therefore blocking UV at the internal face of the glazing can be just as effective as external treatments. The coated glass operates on the same principle but the coating is usually much thinner to be more aesthetically neutral. I'm going to try some on my SE facing Velux - there's a choice of silver or black tint. I fancy black to blend in better with the slate roof.

You're right about that. Have already set my sights on a Siemens iQ500 for starters. It's an integrated larder fridge rated at 115 kWh/annum.

How much better at keeping out the heat are the external shutters? I was looking at the velux solar powered blackout blinds

Ah, my pet topic. Been sorting out impossible door locks and electric awnings all day so only got to this thread now 😬 But it turns out you've all pretty much got it covered (especially @joth's 8 point answer). The Emporia Gen 2 looks to be quite a decent bit of kit but I'm not impressed by their response in their FAQ about why their API is closed. To use the excuse that they're only a small team seems pretty lame to me. Does this imply that it's so poorly devised that they don't want anyone to see its workings? I doubt it. Really the free 'cloud only' option smacks of them reserving the ability to charge for this at a time of their choosing. Several high profile players have already closed down services when the cost of providing server bandwidth for free became unviable. @Benpointer If you opened up your CU would you have access to all the circuits you want to monitor? @billt is right about the benefits of the more compact toroidal CTs if you're prepared to pop a few wires off the busbar (you can use circuit Neutrals) but without lots of tinkering you might not be able to make them work as plug-and-play with the Emporia. But because of the limited cable length all your circuits would need to be inside the CU and I doubt that this would be the case. Can't fault you on that except for if it means compromising on what you really want. I've often faced this dilemma - sometimes the only way to get exactly what I want is to make it myself. For a distributed system I would point you to the PZEM-004T as the measuring device and ESP8266 or ESP32 programmed in the Arduino environment as the comms link to datalogging via MQTT. This way you can get the granularity down to a reading every second and keep all the data to yourself. You could get one up and running to begin with then replicate as often as you like. There's a Arduino Library ready to go for talking to the power measuring module.

I wouldn't totally discount timber framed windows myself. Wooden frames have comparable U-Values to UPVC. I've seen some that perform better. My preference for them is based on appearance - UPVC always come out bulkier with less area for the glass for a given sized wall aperture. As for maintenance, yes they need an application of good quality exterior paint once in a while, but regular washing down can reduce the frequency. All UPVC windows that I've had experience of have become scruffy on similar time frames but then there's little that can be done to rejuvenate them after that. PS your house looks a little bit like mine. Square leaded windows just don't sit right in UPVC IMO.

The maffs is hard. REALLY hard. Way over my pay grade. But it's not needed at all to get an understanding of QED. The maths is only necessary if you are going to apply it in a practical sense to an actual task like, say, working out what curvature of glass you need for a lens with specific properties (from first principles). The clever maths is there to provide short cuts to otherwise impracticably tedious but simple operations. A bit like how a lawn mower gets your grass cut: it's a simple process that you could get down on the lawn and do with a pair of nail scissor - but you wouldn't. In this analogy the mower represent years of postgraduate training in advanced maths which lets you take a big swipe at the problem and get quick results. Feynman makes a big deal about this distinction which is why he delivered his series of lectures to a very wide audience.

Oh dear, you've got me triggered. I think it's just astoundingly beautiful. Quantum electrodynamics (QED) is a mathematical framework that captures all the ways particles like photons and electrons interact. That all sounds pretty dry until you realise that this effectively covers EVERYTHING that isn't gravity or nuclear forces. There should then be a double-take when you see that this means EVERYTHING from the strength and all other physical properties of materials, the way that heat and light reflects, refracts and radiates... you name it, it doesn't matter what you point to - apart from the unsubtle effects of gravity and the all too subtle effects of nuclear forces - all our daily interactions with the world can be described with QED. And if that wasn't enough magic, at the very heart of QED is the principle that it all comes down to little spinning clock-like vectors. Honestly. Pick up a copy of QED The Strange Theory of Light and Matter if you're curious to see how something so simple could explain so much.

Brushless is best. A Stepper Motor salvaged from a laser printer perhaps? They generate useable AC power at far lower rpm than brushed motors (I've got a pile of those as often you can buy a new printer with a full set of toner carts for little more than the cost of a refill. Hopelessly wasteful unless you turn them into parts!). Still think a traffic cone would be good to funnel the water in...

Are you sure it's just water in that glass? 🤣 Aaargh - a swarm of those pesky little blighters drove us indoors during our alfresco dinner this evening as well!

Go out and nick a traffic cone.

Why thanks! So earlier I was scratching my head over this coating thing... I know the coated surface reflects a different spectrum to the uncoated (hence the blue tint to the second reflection) BUT how come the next two out (uncoated) return the same untainted spectrum as the first? Actually the answer is right there in the word 'untainted'. It's not that the coating acts as a filter (like a toffee wrapper) but returns (i.e. reflects) a different spectrum. Obvious when you think about in terms of Quantum Electrodynamics 😁 Aw, if only Feynman was still with us 😔

Do you know the trick to see if the glass is coated? You shine a light (smartphone LED good for this) and look at the colour of reflections from each glass surface (four for double glazing, 6 for triple). The coated one will look a slightly different colour... This shows the coating is on the outer surface of the inner pane of my coated double glazing.

LTSpice - wonderful bit of free software from Linear Technologies. It simulates circuits to save you blowing things up for real!