joth

Of course they can ask... Real question is would it be successful. It obviously depends a lot on the area and demographic of potential buyers. In 2021 a local estate agent said ours could achieve up to 25% premium for the "right buyer", which apparently wasn't unicorn hunting, at least he claimed he'd already had people walking in off the street asking for a passivehaus. That was 3 years ago.

I'm fairly sure it's a certified Passivhaus, I know the architect and build team and it's what they were aiming for. It's one of a small development of three. I can't see it on https://passivehouse-database.org/ yet - certainly would make sense from a sales PoV to have it listed and details included in the advert. Price in this area is largely defined by distance to nearest mainline train station and quality of the local schools. The guide price is in line with the going rate, so on the low side of what it will raise if a PH motivated buyer turns up. EDIT: bit more pre-build info here https://www.adpractice.co.uk/st-albans-passive-houses

Sometimes when people say they "don't need building control" what they actually mean is they don't need a Full Plans application, and can do it via a building notice. So maybe clarify if this is what they're thinking of? https://www.hertfordshirebc.co.uk/guidance-note/full-plans-and-building-notices/ Personally I'd do the full plans application anyway, else you risk failing BC after the work is already done. For a garage alone less tricky but with living accommodation included there's a lot more boxes to tick. Thermal performance, fire doors, escape routes, sound proofing ... Other times people mean they heard someone else got away without doing BC at all. It's true, it's a self notifying process so odds are reasonable you won't get caught if you fail to send the notice. It's a false saving, and will absolutely catch up with them as an additional headache when the property is sold if not before

So 30W/m2 - about twice the energy demand of our retrofit. (We achieved 0.5ACH) I'd ask them to do a calc with the MVHR recovery figured in too, so you can get an idea of the likely real-world demand. Mine was way over spec too until I did this.

FWIW I suggest this could prove a fragile way to specify requirements. A six year old child may yet grow up to enjoy growing their hair out very long, regardless of gender - who knows what the fashion will be for post-zoomer generation. A teenager of dating age may desire long shower times regardless of gender. The future owners of a 5 bed house may have any various needs for many long showers or baths.

Do all 4 bathrooms have showers? With 5ppl in the house, 3-4 showers could easily be used at once (if your water pressure & flow are up to it). The boys are approaching the ages where showers will get longer too. I'd be looing at 300L minimum. 400L if you have space for it. A 11kW ASHP will recharge it pretty well. An alternative / addition to oversizing tank is to store water at a higher temperature. If you get the new R290 Ecodan it will heat up to 70C, obviously at a hit to COP but an option if you're space constrained and think you'd only "sometimes" need the higher heat energy storage capacity. Place it somewhere central and the heat losses will offset your heating demand in winter. (Think about mitigation if you do get overheating in summer) You say it's super insulated, but 9.6kW suggests it's either >400m2 floor area, or not that thermally efficient really. Do you have an airtightness target, and did the heat loss calc take it into consideration? (The MCS protocol typically doesn't)

This issue is with adaptive flow compensation. What temperature is it generally flowing at? Do you have it on a timer schedule or running 24/7 ? With well oversized rads and left of for long periods it should be able to modulate down to a very low flow temp which would mean the rads in warmer rooms having negligible output. But if for some reason something is making it run at a higher temp than per room controls of some sort are very likely to be needed.

Lots of opinions of them in this very recent thread. It depends on the heat loss profile of the house in question but tldr unless there's a very specific problem you're trying to solve that it's suited for, you're almost certainly going to save on both capital and running costs by using the ASHP manufacturer's proprietary controls on their own, per @JohnMo comment

Just to clarify my answer above was for terminal ends, with a single cable. For daisy chain intermediate nodes that have two cables I always gel crimp ALL unused cores to pass through to the next switch in line, in case ever needed there in future. These I'll wrap tight like Rob and stuff in the back of the box

I do something similar, normality wrapping them around the jacket of the cable they come in on If they're connected at the far end, or any chance they may ever be I'll cut it a bit different length and electrical tape it to ensure it doesn't touch any neighbours or backbox.

A variation on #3 is they may charge you an additional fee to put right any issues in the CU install before notifying it. That'd be my favoured answer as then you know the work is safe and up to standard and you have the certs and BC notification you need.

Fwiw we have 80mm screed throughout ground floor, a batch charge it overnight cheap rate (octopus Go) for up to 3.25 hours, about 20kWh heat production, which slowly releases from the screed over the next 12+ hours and is generally all the heating we need. Generally under 60p of electricity input a day. (161m2 passivehaus retrofit) To get maximum energy dump during the cheap rate I crank the flow rate right up (based on outside temperature too) and then back it off down to 28°C as the screed temperature approaches that temperature, to avoid cooking the bamboo flooring (I can also close off loops where the floor is overshooting temperature, but that's rarely needed now I have exact control over the flow temp). All automated with Loxone and modbus interface

To ask the other question, do you have 3 phase? Or any of the agricultural buildings around you have it? This may allow 3x export without the need for a G99

It can be done single phase, but 3.68kW per phase is the limit for dno notification without pre-approval, so going 3 phase avoids the need for G99 process (which isn't guaranteed) If you source components yourself you'll need to handle the VAT reclaim on it yourself, and be sure you purchase an MCS certified inverter if you want to get the installation cert.

Looks like you've set tank temperature to 56° and turned on the immersion heater (Choc thermique?). That will hurt your wallet. You should be able to get acceptable shower temps of 48° or so without needing the immersion on all the time.

Look for the ecodan data book, perhaps here https://www.mitsubishi-les.info/database/servicemanual/files/201803_ATW_DATABOOK.pdf Page 100 onwards, you need the exact model number. 1PH means single phase (not 3 phase) The best case COP is at air temp 15° so irrelevant this time of year.

MELcloud is very limited in the info it provides, a few graphs but little in the way of numbers, and no COP. Part of the issue is the underlying modbus interface to FTC6 only reports power at kW precision (which is little better than an on/off signal for lower power devices). The previous day usage is reported in Wh to high precision but no good for understanding behaviour through the day. To get good tracking I'd be looking at a separate device but it would mean plumbing in an additional flow sensor. (Unless the signal from the FTC one can be split, I may actually investigate that possibility)

Interesting I hadn't heard of this before. Seems like something Homely will need to provide for their products

OT wondering why this is in "Forum News and Site Issues" Ahhh "site issues"! I get it 😂. I think this topic really means "website issues" but this works

A reasonable compromise my current project has struct is all wiring infrastructure and "peripheral' devices (lights, switches, sensors, relays, HVAC & PV interfaces) are using open standards: KNX, DALI and a bit of modbus. So the only single-vendor bit (Loxone miniserver) is confined to a single wiring enclosure. In theory if Loxone go up in flames, it's not too invasive a job to drop in a Gira or LogicMachines server in place. It'd be hella lot of re-programming and the user experience would noticeably change, but no need to rip any walls open.

(Sorry dipping in haven't read all the pages) Do you know where the 3 port diverter valve is, that switches from UFH to DHW? If that' near the boiler, there should be a dedicated flow/return pair from boiler to tank so easy to switch to 4 pipe. If it's far away then you're stuck with what you got (unless you fancy pulling 2x new pipes from boiler to tank)

Actually, perhaps it goes support sub distribution boards, I found an option for it. I think the idea is you need exactly one Emporia per board. I don't have two Emporia so can't test it (and won't be buying another due to the battery/PV limitation)

Emporia supports 3 phase pretty well, setup detecting and confirming the phases (designed for US split phase installs but supports 3ph too it seems) However it's not good for anyone with PV generation or especially bad for bidirectional loads like battery storage. The main meter clamp detects power flow direction but it seems the individual circuit clamps don't, so it detects charging and discharging my battery as the same thing. Also it only supports a single distribution board really. It's a good product for quick and dirty monitoring setup but not something I'd want to use for fully designed long term monitoring. The lack of flexibility in setup and especially lack of local API is too big a limitation. Shame as it's excellent value and for what it does support a well implemented bit of kit.

So I actually never use them at the TB end. Spring loaded terminals are (generally) designed for stranded as well as solid core wire and I generally find it easier and quicker to put them in non ferruled. You do have to press the release button right down when inserting them and of course this doesn't work on solid core only terminals without a release button like the Loxone link and knx wago blocks. One time on a hundred a single strand will sneak out into its neighbour's hole, but it's part of the fun debugging those case 😂

Modbus even more so. Maybe DMX and Dali, a few others. MQTT is stuck between camps. Unlike KNX etc it's not a complete standard, just an application layer protocol. (A bit like modbusTCP or KNX/IP). It depends on a lot of other stuff to work, ethernet and IP layer, stable device naming or addressing, and good luck if you want TLS encryption. I certainly wouldn't want to build core house functions like lighting and heating around it. But nor is it consumer friendly either, it takes so much manual config. It shocks me to hear myself say this as MQTT support is one key feature I find shocking to be missing from Loxone, but maybe I just answered it 😂. Loxberry is moving to use it as the core messaging fabric. Maybe things will keep moving that way.