joth

Did you record the outside temperature at all? Otherwise any experiments are quite meaningless. In my experience (in the UK) using a thermal imaging camera any time other than winter (sub 10°C outside, ideally sub 5) won't yield much useful information at all. Will be interested to see what you can achieve in mid summer.

Have you considered bioethanol fireplace in a wood-burner style cabinet? They're pretty good for creating the ambiance, and If you have very high levels of insulation you might find the real wood burner to hot to ever use. bioethanol is much easier to temper the heat output of so you might actually use it more. And has many additional benefits (minimal particulate pollution, no penetrations in the airtight envelope, potentially easier to source and store the fuel, depending on situation)

Orthogonal to your question, but interested if you've had a structural engineer or building control approve this design yet? I was just mentioning on another thread we had trouble getting an insulated slab approved on a retrofit, so interested to hear others can do this. The fact you had a suspended floor to start with maybe of relevance - depends what the existing concrete slab is actually doing I guess.

conc slab on top of insulation can be fine for a clean sheet new-build, but on a retrofit where you're digging out an existing concrete slab, you may have challenges getting a SE and BC to sign this off. We certainly did. As we were digging down deep there's a risk of disturbing the existing strip foundations (that were unknown depth/quality until we'd already committed to work, i.e. post BC design sign off), so all they would approve at the design stage was MOT->slab->insulation->screed. So we ended up with UFH in 80mm screed on top of 160 - 260mm of insulation (thickness dependent on the depths we could dig to in various places). Not ideal, but this is retrofitting for you. We also tried to do a raft foundation in the extension, but this was rejected after doing all the ground works as the BI decided the raft might float away from the existing house strip foundations.

forget about the PV and sort out insulation underneath your new wet UFH. Now is your only chance to do that. As you say, you can come back later and add PV

We did something very similar to this. 200mm pavatherm EWI retrofit on existing 60s B&B cavity wall, and extension is 300mm blown cellulose TF with 80mm pavatherm EWI. Thermal bridge free all the way around Likewise the EWI is continuous up into the roof insulation

Thanks. It's £299 at plumbnation (fulfilled by Gledhill) so what the heck I've gone ahead and ordered. I've got a fun project ahead figuring out a bunch of MBSP adapters and draining and refilling a system full of Glycol. I hate plumbing

I made a mistake in my original response. I take it you mean a UVC using the normal DHW connections? Just coming back to this to finally place an order. Again the same question arises: a 120L UVC costs less than a buffer tank. https://www.snhtradecentre.co.uk/product/gledhill-es-120l-direct-unvented-cylinder-stainless-steel/ vs https://www.plumbnation.co.uk/site/gledhill-stainless-lite-plus-direct-buffer-store-cylinder-120-litre/ Any reason not to use the UVC? It has a complementary PRV. 2x immersion heater and expansion tank...

I wish we'd installed it upstairs, for increased cooling capacity, not for heating! Like others we currently have no heating upstairs and it still runs 2-4ºC warmer than downstairs. Stack venting cools downstairs a treat, but the house stratifies the warmth very well and retains it upstairs. For a new build I guess the cost is negligible but we were a retrofit and installing upstairs would have been quite a lot of expense, so still glad we didn't, but I now have a never ending project getting the upstairs FCU installed and effective.

The sensor is probably a simple thermistor or possibly a "1-wire" digital sensor, either way fairly easy to extend the wires on it if you need to. Just make sure the joint is water proof if it will end up under the floor at all. (I like to solder the wires, cover in epoxy and heat shrink, but other methods exist) My ASHP controller doesn't have any underfloor thermostat (although I added one for my own data logging interest) - it uses sensors on the UFH flow and return pipes

Very similar here. I was given a miniserver by a colleague and initially I just hooked up various super cheap switches and bulbs via to the built in digital inputs and outputs. I trusted that the Tree gear would "just work" if I ever bought any, so was more interested to learn about interfacing to less proprietary standards before committing. I played with KNX a bit (and discarded using it at all), got the dmx extension and then got comfortable using the Loxone config programming software before deciding to commit. All in a lot less cost, and a lot more educational for me and my goals, than buying a demo case.

Which year was it that the challenge to become a SI unit pedant? We certainly noticed that one 😆

So true. It's a small mercy they didn't restrict 0% VAT on tampons to supply & install too.

You can do it either way. Some people like to run DMX all over the place to have drivers in the ceiling void with the lighting fixture. Personally I don't like that as DMX is a pig to diagnose if something goes wrong so my DMX universe is strictly internal to the Loxone cabinet. Per the title of this thread, I use a start topology with one power cable back to the cabinet per light (or logical group of lights). If I need any remote DMX actuators I'd put them on a separate DMX universe, probably via an IP to DMX bridge. Another option is to use a DMX amplifier/splitter which at least separates branches from each other at the physical layer (separate termination resistor needed per branch, but not as clean as independent universes)

Agreed, but if you have the DMX module already I wouldn't even consider Loxone dimmers, get DIM rail mounted DMX mains or low voltage drivers http://www.whitewing.co.uk/acdim.html

Yes, I bought my "Panasonic" FCU from shopclima, (actually rebranded Systemair unit). Rather tatty condition package by the time it got here, but otherwise do drama (pre-Brexit). Note the size of FCU makes a big difference to the price, and you need to size it (and the buffer tank) carefully both to be effective and to avoid short-cycling the heat pump.

We will have a motorised velux at the highest point (my architect is mad keen on velux for purge cooling) We have this (actually, a Fakro PH window) at the highest point and it works great for cooling. Overnight it's much more effective than the ASHP (via UFH or FCU). Couple notes: - we also have an opening rooflight in the ground-floor extension flat roof, opening both together is most effective to create a through-draft - the open plan area, inc hallway stairwell and landing, all cool down fabulously. However, the bedrooms tend not to benefit much as we keep doors closed (no cats in bedroom policy!) which means I'm still working on designing in some extra mechanical ventilation to push cold air around into those rooms more effectively. (The MVHR, even on bypass and boost in winter, isn't enough to compensate for 2 human bodies in the room) - I really appreciate the home automation for keeping track of indoor and outdoor temperature, heating and mvhr status, and current rain status, and automating the skylight open position accordingly. - originally I just had it "open" or "close" but it's a bit slow to move between end-stops (30secs?) and a bit noisy, so when at the threshold temperature it would clatter all night opening and closing every 15 mins. so now I set the skylight angle proportionally to the amount the house is over target temperature, which very nicely modulates the window down to "closed" as the house cools down, and gradually opens it up as it warms back up.

You can still make changes to the trees (esp lopping that maybe needed for safety), you just need to file an application https://www.gov.uk/apply-work-on-protected-tree We've done several

The problem is 30 years ago the government decided to sell off BT so they could profit from it, rather than invest in making it ready for a digital future https://www.techradar.com/uk/news/world-of-tech/how-the-uk-lost-the-broadband-race-in-1990-1224784

Hmmmmm. Our evening cooking generally starts after the sun is down. Either of our 3kW oven or the 5kW on the hob is going to empty that battery PDQ and then there's all the evening's lighting and entertainment. And in winter the battery may not get recharged for days if it's cloudy. I think paramount to going off-grid is completely changing to an off-grid compatible lifestyle. Taking that to the extreme, why bother with electricity at all?

Overall, while smart way of maximizing self use of PV this probably isn't a very helpful for achieving fully off grid. The limitations for off-grid will be in the depths of winter, and you won't have enough excess solar to achieve these higher temps on those days. If you're only using the cylinder for DHW that's a very small part of the challenge anyway, but if it doubles as a thermal store for the heating system then this could make a dent. I'd say this maybe one case where a wood burning stove with a back burner has its place. Even if you can't grow all your own wood fuel on site, it can be grown a lot more locally than diesel which feels closer to the ethos of self-sufficiency

I went for the same plan, however note you need thermostatic mixer taps for this to work. the cheap tap we ended up choosing for the utility room turned out to be a basic mixer tap so does scold on a sunny day when the PV has been busy. Also the bath filler doesn't have a thermostat so the amount of manual mixing needed varies by season. We'd have to fix both these if we ever decided to let the property

That shouldn't be any issue, just make sure all this is understood by whoever sizes the SWA run from the kiosk to the house. You can use a 3ph PV inverter and that avoids all the G99 approval bother too.

A common option is to put the "temporary" meter in a green kiosk at the boundary (cheapest location for the DNO and minimises risk of cable strike) and but leave the meter there after the build as the permanent solution. 7-8m run from there into the house will be fine. You may get a slight dimming of the lights when there's a surge powering up your circular saw etc, but the steady state voltage drop is not enough to be any issue. Smart usage of all 3 phases will minimise this effect further. Edit: xpost with MrPunter, we're saying the same thing

IME The main issue will be the air flow noise, rather than the FCU motor. You can locate the FCU some distance away and isolate it from vibration, but the challenge is the quantity of air movement needed for any effective heat transport is always going to have some noise with it. Largest duct sizes you can manage and oversized grills and plenums is the best shot I'd imagine.