joth

So first, so long as the standing voltage at your property is acceptable even when you're drawing max load, then the length of cable running into your house has little bearing on the length you can run from your house onto an outbuilding. The power loss (voltage drop) along a long cable run is proportional to the current being drawn. Using large diameter cable will reduce the effect. There's voltage drop calculators that can give a ballpark idea. This one says 10mm2 swa will have 8V drop when delivering 6kW over 80m, which should be fine. If there's still issues, if you can shift the high power loads off of electric to bottled gas then the remaining loads (lighting and a phone charger) will be no problem at all.

This just BS policy though isn't it. All it takes is a Nova of teenagers to park underneath the mast and your 10Mbit will drop to 10Kbps. And mobile standards and operators change so fast that having some coverage this year means nothing about what you'll have next year. Honestly you can install Starlink anywhere in the country (or out at sea) and get over 10x these speeds anyway. So wired USO is obsolete concept if wireless can satisfy it. (I'm just grumpy at OR as they won't install FTTP for our house for less than £8k despite being in the middle of a town and every other street having it. Our street has underground GPO copper so apparently not worth their effort)

Goodness if the battery caused any issues with house sale I'd just disconnect it and take it with me.

Interesting, when we extended and attached our garage in 2020 we didn't install a smoke detector in there and no one suggested it Tbh there wasn't much point when it just had some storage and an inverter, but now it has a battery probably worth me adding one. (Even though solaredge battery has built in fire suppression... I'd still like to know asap if anything was smokin out there)

What's the full list of parts you used? I've been faffing with various sensors for shed at bottom of garden - wifi coverage is great there, but sucks for battery life. I've now bit bullet and pulled Loxone tree down there. But Lora always seemed an interesting one

Very timeline thread. What sort of temperature is that room maintained at? My garden room is a gym, so naturally gets a lot of humidity, and we positively don't want to heat it at all which means it's always sat at/below dew point and creating lots of pools of water esp around the door handles and window frames (cheap 2G). The trickle vents can't keep up. I've set the A2A to do a dry cycle during overnight cheap rate, but it's already so cold that I don't think it can shift much by cooling the air to condense water out of it. For the little money it costs I'm very interested to give this dMEV a go. Current situation

Don't underestimate the amount of effort it takes to install and maintain a generator that will reliably start and take over supply while the property is unattended in the middle of a storm Personally I'd go with the @Beelbeebub approach of put in antifreeze valve at lowest point you can below the ASHP But if you want an autostart generator for other reasons too, why not.

A few thoughts arising from this... That's US news, there's a million billion things they do there that our utilities would not consider fair, and vice versa. So "us" == US citizens in this instance; UK citizens access to power will be dictated by UK regulators However it's really not surprising in when most generation is privately owned. It's all just market economics at the end of the day There's nothing new under the sun. Google has been doing it for at least 2 decades: their very first privately owned data centre opened in Dalles, Oregon in 2006 was on the site of an old aluminum smelting plant, chosen for it's direct connection to a private power plant and fresh water supply.

FYI your address is still visible in these plans (in the embedded document title - \\WOOKIES-SERVER\SharedFolders\Wookies Documents\..yadayadayada..)

In this case forget about the heating system. Start by working out how you are going to get 160mm+ of insulation under the floor, remove or minimise thermal bridge through all the existing supporting walls+foundations, and seal junctions to make it all airtight. That's going to be the expensive/labour intensive part of the job. Once done you have various options on UFH you can price up but they'll be a fraction of the above works. (On our Enerphit, we had to dig out an existing 60s concrete slab and excavate down 500mm to completely relay the floor slab - one of the more expensive steps but once we decided this all the other decisions pretty much fell into place around it) A QS won't design it for you though - you need to give them some detailed plans of what floor/wall/roof build ups you're going to use. I'd start with a PH designer or PH architect. even if you're not going for a certified retrofit, they'll be best placed to give you the options in your budget.

Costs depend vastly on what your starting point is, which is not very clear. Do you already have a completely finished occupied house you're planning a heating retrofit to, or just some plans being prepared for planning permission, or something in-between?

Yeah I agree installing MVHR without the HR is a pretty silly suggestion, but no more so than taking the heat recovery energy savings as a good indication of the full system savings as I was previously doing. And MVHR without the HR was the simplest way I could think of to make a valid apples to apples comparison. You're probably right that some kind of dMEV is a better comparison but you'd have to adjust for the fact it's more to run (more filters, more motors) and less efficient (more external penetrations) than central MV to every room. Whatever I'm philosophically opposed to paying good money for windows with intentional holes in them so was never a moment of consideration for me.

Yes totally agree. Given building regs require proof of sufficient ventilation in every room they're almost mandating it (they will be just as soon as the bar gets set high enough to outlaw unmanaged ventilation)

Do you mean wrong morally, or you found something wrong with my logic? We literally embarked on the deep renovation purely to install MVHR and got dragged into the whole Enerphit project as a side quest while trying to improve airtightness to fit said MVHR. So whether it is "Wrong" or "right" I can promise you, without the goal of managed ventilation we'd have just spent a fraction of our budget doing a conventional extension and redecorate like the other 99% of house renovators "wrongly" do every year, retaining the original airtightness of a 1960s house.

No. However I would have paid more than 5p per additional marginal kWh of delivered heat over last 4 years, and predict I would pay more again on average over next 6 years Actually I just realised, the 2000 kWh / year saving is compared to having perfectly managed (mechanical) ventilation without a heat exchanger. So the relevant cost saving here is the heat exchanger itself which is £800 Inc VAT (Zehnder Enthalpic) so pays for itself in under 8 years even at 5p/kWh for extra heating. (Shorter if paying more for heat) In reality if I hadn't installed MVHR then we'd: (a) have trickle vents, (b) renovated to a much lower airtightness goal, and (c) have the windows open much more of the time, even in winter. Together these three would yield far greater (and largely unmanaged) heat losses than that what the Heat exchanger is recovering. The principle savings come from the upgrade to managed rather than unmanaged ventilation, and the heat recovery is just the icing on the cake. And I should add I've also automated the window opening and closing now too, modulating the window gap according to needs in summer, so even that is managed. That's the cherry on the icing on the ventilation cake.

No. However I would have paid more than 5p per additional marginal kWh of delivered heat over last 4 years, and predict I would pay more again on average over next 6 years. It's a weak comparison without factoring in inflation, prediction of future energy prices, and opportunity cost of tying up the capital, which ICBA to do given I didn't install for financial payback. It's O(10) years. Good enough

Thanks for the recommendation! I finally got around to watching this. Incredible. That French interior designer seemed a right knob but the rest of the team seemed a really solid crew. Bearing in mind it's all put on for tellie, Paddy McKillen especially came over really well, so hands on - sad to see he's now in a multiyear billion dollar battle with Qatari Royal Family over it all, but hey - it's tough at the top. I've been trying to find info on their new plant room architecture. Like how 5 floors below ground does Aircon work - do they still have roof mount chillers or do they dump heat to ground? Or to pre-heat incoming mains water? etc. What else does the CHP feed? What is their mix of gas vs electricity? So many questions! Searching around there's a few promo articles from suppliers e.g. on the BIM tools and recounting the impressive dig out, but not much else. It'd be fascinating to see much more into how it now all runs. https://www.linkedin.com/pulse/tech-stack-behind-epic-renovation-claridges-hotel-uk-steffen-waite/ https://www.newcivilengineer.com/innovative-thinking/ingenuity-behind-claridges-five-storey-mega-basement-01-08-2019/ https://kanegroup.co.uk/case-studies/claridges-hotel <- Promo video from M&E installers https://committees.westminster.gov.uk/documents/s20607/ITEM 04 - CLARIDGES HOTEL 47-57 BROOK STREET MAYFAIR LONDON W1A 2JQ.pdf <- the original planning app decision

I also installed mvhr for comfort rather than financial payback. But it claims to have saved over 2000kWh per year since installed so will pay for itself in ten years. The fact it uses power is negligible. It's about 3% of the saved energy. But again, it's for the comfort. Every previous house my wife would constantly be opening windows (to remove humidity to avoid mold) and I'd be constantly closing them because it was so damn cold. So I guess the biggest financial saving was mvhr has saved us a costly divorce 😂

That...... actually makes sense

Yes to this, obviously you're incurring unnecessary cost of room stats, actuators and installation if you go this route. Also in a lower (BR) spec property you'd risk one outlier cold zone calling for heat too much and driving everywhere, but the calculated heat loss suggest this is a better than BR property so most likely work just fine without zoning. (Aside - do you have MVHR and planning for good airtightness? This is likely the difference between the heat calculation methods) In some cases I find zoning useful to avoid bedroom overshoot - but the easiest and cheapest solution to that is simply not put UFH into bedrooms at all if they're upstairs. If you're sufficiently savvy then installing without zoning but with a plan for zoning should it become needed is the alternative tactic.

Sounds like a cracking opportunity for and a2a heat pump. Less power draw for more power output, and built in slow start to boot.

Did you try the Tuya mmWave offerings at all? https://www.aliexpress.com/item/1005005477612297.html much as I dislike wireless sensors, at less the £10 each they seem worth a look. it'd have to be Zigbee as their wifi models are effectively locked into dependency on their cloud service ... and some report they spam the zigbee network quite a lot. Actually... https://smarthomescene.com/blog/best-and-worst-presence-sensors-for-home-assistant/ has me looking at the Apollo Automation MSR-2. it's a little bit more ~£30 but is very interesting - native ESPHome so easy to add custom notifications, temperature built in and CO2 can be added at a very reasonable price. Just darn ugly.

2 years on, it looks like Zehnder now have an officially supported option for a local BMS/HA integration in the "ComfoConnect PRO" https://www.international.zehnder-systems.com/en/comfortable-indoor-ventilation/products/connectivity/smarthome-for-ventilation-systems/interfaces-for-smart-home Of course costs even more than the ComfoConnect LAN C, but it has modbus RTU/TCP built in. Very annoying they've in recent years they pushed FW updates to the LAN C to enable cloud service, but haven't added not modbus TCP support which would be relatively simple addition in comparison 🙄 Also funny to see "Google Protobuf public AP" listed in the table above as not supported by any device. That of course being the private API used by their app, and also used/abused by Home Assistant and Loxberry plugin to get local control over the LAN C.

So my guess... One of the main intents of BUS is to support wide scale training in domestic HP installation, hence the instance on MCS and encouraging profit taking by those with said training. Domestic plumbing is seen as a wet plumbing not F-Gas skill set and so they want people to cross train into the skills that are typically needed to maintain these things going forward

Correct, cooling is not prohibited in a bus install. The two challenges with cooling are (I) it's not allowed under permitted development, and (ii) MCS training doesn't cover cooling (MCS install being mandatory for BUS) so it's extra hard to find an installer competent to do it. In practical terms so long as you keep the cooling temperature above dew point there's not a lot of additional effort needed to support cooling.