joth

Where are you in the build? Has the certifier already issued design stage sign off? Who is listed as the PH designer in the file? Do you have the spreadsheet? Who is going to file for post build certification, including making any other PHPP updates to anything else that occurs during the build? (Not least of which is the final airtest but there could be any number of other minor edits during the build really) On our build I made some edits (mostly to the plumbing and ASHP details) but I fed them back to the passivehaus designer (also our architect) to include into her copy. Otherwise my edits would just get lost whenever she made subsequent updates.

*Sigh* No, with a polyphase smart meter, it will net across phases so export on one will reduce the metered import on another phase. Does the smart meter have a indoor display of real time usage? This would be the quickest way to confirm what's going on. If it doesn't, maybe it's not a smart meter at all. Maybe share a photo of the meter.

I'd just put an outdoor style tap in there and hookup a hand held shower head to it after BC signoff...

Great to hear you are making progress at last on this! Interpreting this with a bit of license, they're saying that it's a 3 phase inverter, but your house is only consuming power from 1 (or 2) of the phases, so even if you turned everything in the house one, you'd never be able to self consume all the generated power as some goes on a phase you don't draw any loads on. This is absolutely fine, so long as you have a v2 smart meter. (Do you? sorry can't see it in this thread but I though you had said), or a correctly configured dumb meter, it should balance out the phases (using net-metering across phases) so e.g. if PV generates 2kW on each of the 3phases, but the house draws 5kW on a single phase, you shouldn't be billed anything for import but get paid 1kW for the net export (3x2kW - 5kW) if they start fobbing you off saying your whole house needs rewiring to use 3phases push back This probably means the new inverter requires a different number of strings, so they need to chain the panels a different way. This should be fine.

Does the cool energy ASHP have any control over it's flow temperature? Ideally you want load compensation: turn down the flow temp as the building temperature starts to approach target. This way the manifold is just a safety backstop rather than being the main control of UFH loops, and you might squeeze a better cop out of the ASHP too

But but but, 40A or smaller fuses are common place in Europe (in France you get higher standing charge the bigger the fuse) so if it's not already supported chargers will soon come with the option to shed load if import exceeds some defined cap. It's already super common their to have contactors that automatically shut off some loads of approaching the supply limit. All that said, personally I'd do the 3ph before I got vaguely serious about installing half the gear mentioned in the OP, but I don't think the OP really is and they're future proofing for things they'll never install. Else they'd already have got 3ph without complaint.

It's worse than that, the electrician appears to be adding up a lot of equipment that hasn't been bought and won't be installed for many years. If you put the oversized wires in but don't connect them into your consumer unit (which you really shouldn't anyway if the other end is just dangling in the air) then it's just a bit of dead burried copper. There's literally nothing there for the electrician to certify. I'm all for ppl installing 3ph when they have the option, but this seems to be bullying you into it over hypothetical possible future scenarios. Seems mad to mad.

Could you PM me the sign-up link? I'd be interested to read up more on it

But very easy to consume the residual ~2kW in winter, that which the 10kW system will then only provide ... Yes absolutely, wasn't trying to say exporting some in summer is an argument against buying PV at all / in those quantities, just flagging the OP should think now about strategies of what they'll do about it to make it acceptable when it inevitably happens.

The 50L cylinder is the buffer tank, so not relevant for your DHW temperature loss but adding equivalent losses to the heating circuit. https://www.cordivari.com/Calorifiers/Inertial_tanks/volano_termico_pdc_hanging The pumps are all in the loft? They're naturally going be much more audible there. We have some heating pipes in our loft (warm loft, so minimal insulation from bedrooms) are they're silent when running, as the pumps are far away in the corner of plant room downstairs.

It will be hard to self-consume those 10kW in summer. Does the install include MCS certificate? To get paid export. Do you have a v2 smart 3phase meter? To ensure you get net billing across phases. Have you considered adding a battery (or two) now? They're only VAT free if bought with the PV.

https://ofset.co.uk/ have some seriously huge options, but not PH certified. And no idea on their prices! Depending on where it is located, you maybe able to get by without a certified product..

Rather than run water to top-up, just heat the tub to stop it cooling down in the first place. simples. https://www.aquaticabath.co.uk/products/627722004484-aquatica-true-ofuro-tranquility-heated-japanese-bathtub

That's a curiously precise number. I'd say the problem is at the temp where condensation starts to form, and then mold is one possible consequence. Condensation is a function of RHI and internal air temp, but sits a bit nearer 15°C in our house.

Unless you have secondary return running all the time, this will mostly depend on the ErP rating of your cylinder. We got a ErP A rated specifically for this reason (Oso Geocoil 300L). It drops about 4 degrees per day, so less that half the rate yours appears to be dropping. It's spec has it rated to lose 1.18 kWh/day, so about 4p per day (assuming COP of 2 for DHW, and on Octopus Go). (Of course being indoors this offsets 1kWh of space heating in winter, so at the moment really only costing 1-2p per day due to COP difference)

Yeah you should ask your DNO for a quote instead. If National Grid are doing it, it'll be coming in hot at 400,00 V and get categorized as a regional infrastructure project. 😉 But yeah shame its not practical, as the trend is towards encouraging more 3ph installs generally.

yeahbut that's supplied from the house's own main feed, so in the context of this discussion this would obviously need to be on the house battery with failover (or a UPS), same as the IP router and Wifi APs. It's all the other gubbins between house and exchange that's in question, but I think with FTTP there should be much less of that gubbins. (That's kinda the whole point of fibre) - In fact, you can ask OpenReach for a a modem battery backup to keep the household phoneline working without the need to retain copper pair to premises https://www.bt.com/help/landline/fibre-home-phone-service--questions-about-the-battery-back-up-un

As others mentioned, which SolarEdge gear supports grid failover it doesn't have the necessary approvals for use in the UK. (You also need an inverter with the dual AC outputs, battery backed and direct grid, which their new HD Wave inverters don't have so needs a transfer switch of some sort). Also to check the other snag here - who is your internet supplier over what technology? Anything using FTTC (openreach VDSL or virgin media) will generally go dark during a power cut anyway, as the local cabinet is most likely on the same supply. It's not like the old days of direct copper to the exchange with its own UPS. Hopefully FTTP would start to reverse that.

As far as I know, A2A has never attracted a government subsidy. They certainly didn't meet the criteria for the obsolete RHI as that mandated "use of a liquid" to provide space heating (and various exclusions around use for cooling, depending on the variant of RHI) The new BUS potentially could go towards a2a unit so long as: - it can supply the FULL heating demand of the property - it can also provide the DHW demand - it is MCS certified install All three of those are currently pushing people towards a2w, but it could change as AFAICT the BUS itself does not preclude a2a.

Actually not the case: Phil is saying you can run the ASHP whenever you want, perhaps timed to maximize COP, and if the COP is better than the ratio of import to export price, you're better off exporting (all) excess PV and (potentially) paying to import all energy required to run the ASHP. With current prices at 33p vs 15p you only need to achieve COP of 2.2 for this to hold. If you can time the ASHP run to be around max PV generation, so around midday which happens to be likely time of best COP, the case gets even better. For my part, I have turned off my PV divert for more or less this reason. (Additional motivation is I now have a battery, and I'm on octopus Go so some import is at 7.5p)

Gu10 downlights work fine in our shared office. The fitting doesn't matter so much as the bulbs used and placement. You can fit dimmable bulbs which is quite nice. We went with 3000K temperature, I really don't like anything colder than that. Will you use computers and video conferencing? Positioning the lights to illuminate faces rather than backlight silhouette is worth some effort. We have whiteish walls so our lighting designer put most the downlights close to the wall so it creates a scallop of light on it and reflects off to fill the room with indirect light which is very effective.

Also, it doesn't look anything like a doorbell so many people fail to find/use it 🙄 (Like the old Loxone intercom, it'd look more at home on a Swiss apartment)

🤮 to that. Even if you can notice the change in load, it will be quite high latency and then the zigbee has to communicate to base. Be prepared to get to the door after the visitor has walked away. Hot-wiring the chime sounds more promising, but still vulgar. Looks like since Nov 22 there's some side-loadable Firmware available for it that adds ONVIF "Visitor" notifications to it, so with a suitably advanced ONVIF client you should be able to get the notifications purely in SW https://community.reolink.com/topic/4412/homeassistant-and-reolink-doorbell-poe https://community.home-assistant.io/t/homeassistant-and-reolink-doorbell-poe/485857 https://github.com/JimStar/reolink_cctv/ If it works this is actually best approach, as it also provides a path for "Face detection" notifications and (hopefully, one day?) 2-way communication with the camera. (obviously caveat emptor about installing sketchy FW images you find knocking about on the internet.) Let us know when yours arrives and how you get on, I might order one just to play with for some other house build projects I'm helping on.

I think the hope here is installing batteries as part of a new build dwelling, batteries are automatically 0% rated due to no VAT on new houses, regardless of if any PV is ever installed. Problem is I can't see any way you can claim batteries are "ordinarily incorporated" into a new dwelling. Notice 708 by default excludes most electrical appliances, and a battery while being professionally is straight forward to take with you when you move. (It's about the same effort as a washing machine.)

Looks really good, PoE and RTSP steam at a good price. Only niggle is there's no way to get a notification signal (neither in SW or HW event) when the button is pressed. So you can't use it with existing chime, or trigger any other home automation when the button is pressed. Seems to me in all the excitement of video they forgot the main function of a doorbell button is to be a button...