joth

Sorry i lost track but is he still assuming a flow temperature of 40°C or something? If you're running low and slow, any rooms that are already over 24°C simply won't take any more heat from an emitter that is barely any hotter than target temperature. Whereas rooms that are (significantly) colder will have a steeper temperature gradient and hence transfer more heat. This is one of the great advantages of low and slow in a low energy home: it's largely self balancing and so you can jettison all the complicated controls as @JohnMoand others evangelise so well here

One thing I'd add is the secondary (output) side of the driver must be 150V d.c. or so, which is definitely not SELV and enough to give a fair belt. So take care handling it and maybe one reason replacement driver would be hard to find. Do you know how many watts the fitting (i.e. The LEDs themselves) is rated as? Here's a 150mA driver which will be fine current wise, but only 6.3W which is likely (but not obviously) too low https://www.aliexpress.com/item/1005009676981309.html Edit: 12W, maybe getting closer https://www.aliexpress.com/item/1005008654656151.html

No, it was oversized to facilitate fast DHW reheat times, and because the MCS installer was skeptical our enerphit would succeed. PHP said 4kW demand but we installed 8kW. This supporting the fast cheap rate heating cycle is a happy coincidence, as in 2019 I really wasn't specifying this based on the existence of such deals.

To get best energy efficiency you'll want to use weather compensation, so you set a curve of flow temperature for given outdoor temperature. Perhaps 35 or more on vary coldest days tapering down to around 20 when the outdoor temperature approaches 20. The only downside of running a very low flow temperature is risk of the heat pump short cycling, which reduces its efficiency greatly, but a large ufh area makes this very unlikely so long as most looops remain open.

It's controlled by Loxone with load and weather compensation, but during periods of very cheap energy i push right down the turn on threshold, bump up target temperature very slightly, and boost the curve based on the difference between the floor slab temperature and target temperature Means i can squeeze out a day's heating demand in about 4 hours operation. The DHW schedule is a bit more hard coded as I want that to happen last thing during the cheap rate block

Even with a 10kWh battery we find Fast and Furious ashp program is still a cost saving in winter, because the battery is fully used time shifting the rest of our demand. (2 people working from home, with compute heavy work). For sure a larger battery would change that, but it's not a good capital investment for just a couple months a year. YMMV, but designing to work low and slow is surely the sensible starting point

Not to contradict this, but this is specifically true for energy efficiency. Some folks talking about efficiency actually want running cost efficiency. With TOU tariffs, in a low energy home, running the heat pump fast and furious for 5 hours of overnight cheap rate electricity can be much lower cost than the low and slow mantra has you believe. So some consideration for higher flow temperature and potentially controls to avoid specific room overshoot can be helpful if chasing low running costs. All that said, to the OP this doesn't really impact the choice of a buffer tank or volumizer, such items are less necessary for short cycling reduction if running the ashp hard, and don't help at all in effective TOU shifting of demand. (An oversized UVC however can be useful if chasing low cost tariffs)

Got it. I expect it's a Tuya motor, extrapolating from their App support info: https://acrimotracks.com/wp-content/uploads/2024/04/Folleto-motor-wifi-EN.pdf A quick search suggests Tuya RS485 is generally running modbus. Dooya is perhaps another brand using Tuya and there's some info on it here https://community.home-assistant.io/t/dooya-curtain-motor-rs485/140398 (inc links to other pages with some code that has position read back support https://github.com/chuanjiangwong/RS485/blob/665bc856cff307b876acc519dcc02d17ec1dec1d/app/rs485d/src/device/curtain/doya/doya.c) so that's what I'd probably start poking around with (either using that code, or more likely using a generic modbus read/write tool) There's also A-OK curtain motors that have a different RS485 (non-modbus) interface, but I think Tuya is the place to start for reasons mentions.

Is it not this device? https://acrimotracks.com/wp-content/uploads/2024/05/Product-manual_EN.pdf Connect pin 1 or 2 to pin 4 for open/close. It has a 220V ac input connector (figure-8 style) to bypass the solar/battery gumpf. I wouldn't bother with RS485 as i doubt it offers anything more than the dry contact input controls. (It'd be lovely if it reported back current curtain location, especially if it supports tug to open, but I doubt it would)

No, you'll appreciate having the wire when the battery (or motor) in these fail and you can't get a replacement. I'd always use wired power and control if I can. Does it not have any option to bypass the battery? In most cases you can use a couple "dry contact" relays to trigger each direction. Electrically equivalent to having a up/down momentary switch to control it. It's just a case of figuring out the pinout on their rj45. If it wasn't that expensive perhaps worth a shot opening it up and tracing the PCB a bit. Or email the manufacturer and ask?

Looks like the Eon honeymoon is over. My one year renewal arrived: Import cheap rate is down from 7 to 6 hours. Price up from 6.7 to 7.5p Export is switching down from 16.5p to 6p per kWh!! Apparently as I'm on a TOU tariff i can't renew export to the higher paying Exclusive tariff. Despite the original renewal offer saying that's what I'd move to As expected they make the list of options complicated enough it's a maze to navigate in the hope you'd give up. Probably back to the even bigger maze of Octopus for me

CO alarm is best kept separate to CO2 monitoring If CO too is high you need a loud alarm to wake you up and get you out the building. (Things that combust continuously, like a boiler, are biggest risk) CO2 is most interesting to see long term graph off, correlate any spikes to activity (house party is classic) or equipment performance. So suggests a cloud or App connected device of some sort You don't need an alarm for it to save lifes in the same way, even in a very airtight build

Link? +1 to that. If keeping the TS I'd just heat it from the 6kW immersion and have the ASHP bypass the TS completely and directly feed the rads (and DHW, if zoning allows). You can then heat the TS to 80degC to increase its capacity using cheap rate at a slight saving vs running the ASHP on expensive rate (savings would increase if the cheap : expensive ratio increases in future, or be wiped out if the difference reduces - who knows). Personally I'd be on the side of removing TS altogether, for simplicity and maintainability. But I'd love to program an intelligent control system for it, just for funsies.

I'd lean towards multiple power supplies in this case. But I'd also wager the whole lot would be fine on 1.5mm2 in practice for the combination of reasons mentioned before.

Loxone recommend budgeting 10W per speaker for normal installs https://www.loxone.com/enen/products/audio/install-speaker/#:~:text=Power supply planning,to safely cover power peaks. Also bear in mind that on a 40m run, no all the current will be drawn along the full distance. It's a ramp function, so on average you can model the full current at the midway point (or half the current the full distance). You can also run it as a ring and feed the power (but NOT DATA!) cores from both ends if you really want. That halves the average current again. I typically run data buses, even strict buses like 1-wire, as a ring back to the node 0 anyway, and only connect one end, as it makes it easy to test for continuity, diagnose issues, and even split the ring into 2 separate buses in case of any issues (cable damage or interference).