joth

Note this link no longer work, since that was the account at our rental and we moved back into our build. (Oh no I hear you cry, so what's your new referral code??? Oh ok if you insist: https://share.octopus.energy/mist-star-414 )

+1 My experience is designing/installing for cooling is the hardest part, not intrinsically difficult just unfamiliar to any UK plumber. But MCS doesn't even train for cooling (still sticks to the it's-not-legal mantra) so complete waste. Has anyone ever met a https://www.flexi-orb.com/ certified installer??

Cycling through Essex a few months ago I saw a modern new build rural mansion with a three story hallway staircase "bolted onto" the side of the house entirely surrounded in glass. I couldn't help but grudgingly acknowledged how impressive it looked. I'm sure it's total hell for heating/cooling, but if designed well (LOL) i.e. to be outside the main building thermal envelope it could act a bit like this. A giant greenhouse. Still be stinking hot in summer though. There was clearly an ungrounded swimming pool going in too, so odds are the whole place designed to hemorrhage money.

Ours has a humidity sensor in the extract pipe so it's automatic. I also have a sensor on the shower that I use home automation to force boost mode but that's just to help get ahead of the steam cloud.

Depending how you're using the 3ph maybe you only need to bring one phase to the house CU and can have a separate distribution board near the meter (outside??) to split our other phases for big things outdoors like EV charger, ASHP or whatnot. Else the EV chargers' power maybe wrapping the house twice. Assuming cars park at the front.

For me overnight electricity is cheaper than midday solar (7.5p cheap rate import vs 15p to export excess) so it's a no brainer to get the tank ASHP hot overnight, then top up from ASHP at midday (or as soon as the battery is full). The only question is whether to then use the immersion diverter for >55°C top off or just export the rest.

One benefit of central submetering is if National Grid start requiring evidence of the specific load shedding, then you can imagine centrally managed supplier gear to be more accurate/trust worthy for them than random appliances reporting being turned off. It'll be interesting to see how this plays out. For my part I'm becoming increasingly skeptical of the whole ToU shifting thing. Octopus already have such a mix of complex import and export tariffs I can't keep up with them, and I'm an enthusiastic target customer for them. Add on top this entire winter I've participated in and scored "points" in all their power saving games, and earned a whopping £2 for my efforts. Consumers are not going to take this up at scale

Absolutely. But doing it with physical control like a fat contactor switch in the submeter is very 1970s E7 thinking. 21st century IoT will have each controlled device individually managed in the logical plane, not via killing the power to them. Reasons I believe this: - E7 tariffs themselves have moved away from using a central contractor - smart meters already have ability to kill the power but it's considered to be unsafe for use in the UK, as (a) there could be life support equipment in the house that mustnt be disconnected and (b) a remote re-enable of power may occur when it's unsafe to do so (worse case someone has their finger in the power line trying to figure out why it's not working). - you can get much more granular control via logical plane e.g. only turn off certain devices, or disable certain operations (comfort heating off, but DHW and eco heating on, etc) - you get better monitoring and maintenance reporting - it's less harsh on an electromechanical device to have it manage it's own power off/on cycle then regularly killing the main power to it. - logical control still works even if the home owner messes about with the wiring topology (e.g. renovation moves appliances around and connects them to different circuits). Obviously IoT brings a plethora of its own challenges, plus the who ethic of revenue sharing for this needs figuring out however it's done, but seems highly probable if it happens at all it will be via digital control of devices.

We had a Q350 installed in 2021. The quotation originally made in 2019 was £5k design and supply, and £1.5k for the installation. 160m2 deep retrofit, 7 supply 6 extract rooms. The price went up £550 by the time we had the work done, partly because of an error from the original sales engineer.

This is not a ludicrous conspiracy theory for why they're doing it, but honestly yanking out the main power supply to an ASHP they already supplied and installed and no doubt have some sort of cloud control over seems both brutal on the device and operationally inefficient on their side. My bet is they did a survey of N hundred existing retrofits and found statistically installing it from the meter box was least agro and most in their power to deliver, so they just blindly quote on that as their standard procedure

It's unclear what stage your build is at, but if you haven't set an airtightness goal and figured out how (hint: written into contracts) you'll get the designer and builder to work to achieve it, then I think doing that is probably a higher priority than choosing the specific heat pump make model This is a good idea, but learn from my mistakes: - MCS tradesmen (and builders in general) are not trained / experienced in FCU install so you need to find a unicorn, or do a lot of the design and install detailing yourself. - remember the whole system will need insulating against condensation if you run cold water for FCU through it. This includes all pumps, filters, valves, etc - typically a FCU will be much lower kW output than a UFH circuit on a house your size, and you often don't want all FCU running at once (e.g. if some bedrooms are overheating but others aren't you don't want to turn them into a refrigerator) so you'll almost certainly need a buffer tank / volumizer on the FCU circuit even if you don't have one (and it's more efficient not to) on the UFH circuit. - installing ducts and plenums for hidden FCU as retrofit is a miserable job so get them put in in the build.

Okay but the question I was addressing was about adding a buffer tank, not a thermal store. You've reverted to talking about eshp here so I presume the topic is DHW heating? In which case yes some way of heating it from PV (or overnight cheap rate) makes sense. A buffer is part of the heating circuit, not DHW, so a different topic but not relevant if you're going a2a.

Which manufacturer is the alarm made by? Most support some sort of system take over process., for when the original installer goes bust. Yours can't have had the programming fuse blown as programming not done so technically should be possible. Contractually may leave you in a sub optimal place though: - you'll probably loose acces to supplier's warranty through the original installer - original installer may still expect programming payment if it was part of their instruction. - who will do ongoing maintenance and support? Most relevant if you're doing a graded system with police call out.

I rebuilt part of my rented house plumbing with help from here during my build. As it happened, I was renting from another BH member who I'm now helping with his new build that's replacing the site of that now demolished rental, but that's by the by 😂

They can, but it can be tricky to engage them prior to tendering the main contract, but without their design input the main contractor doesn't have all the information needed to quote from. As others say these thing don't all need to talk to each other. PV <-> Battery is the only crucial one from that list. Getting individual design & supply quotes for each item and providing to the main contractor is certainly an option, this is what we did and it worked out well. (They went with our quotes on all of them in the end, as they couldn't beat them. We novated 2 of the contracts over to the main contractor, for PV and MVHR, but I kept the ASHP installer directly employed by myself mostly for VAT reasons)

The idea being to heat the buffer from free PV? This is probably not worth it as PV is minimal at times you want heating on. If you use the ASHP for cooling too, there maybe a better case for this.

You can't really just add those two figures together to get a meaningful result, as the airtightness test value is just a nominal value arrived at under test conditions (50Pa pressure difference) which may never actually happen or be massively exceeded in practice, depending on weather and building exposure. Whereas the MVHR flow rate is constant (for a given speed setting).

Just to clarify you're talking combination of capital and running costs based on some assumptions? A2W (possibly extract air) heat pump for DHW (with PV+battery) will give lower running costs in absolute terms. And resistive heating will be cheaper in capital cost terms. So selecting a mix of resistive + heat pump will depend on the assumptions around usage patterns and quality+size of property, and future energy prices, etc. (Not saying it's a wrong or uncommon conclusion , just it will depend on circumstances and assumptions)

https://www.quooker.co.uk/most-frequent-questions/i-live-in-a-hard-water-area-and-wonder-if-limescale-is-a-problem Suggests the scale filter is an option to reduce the maintenance effort, nothing here to suggest it is mandatory. I'd be interested to see where it says it's a warranty requirement, and for which models/years, as I can't see any reference for that. """ We've developed a scale filter - the Quooker Scale Control - that you can fit to take out the excess limescale before it reachs your Quooker tap, making it very low maintenance indeed. It can be used equally well with an existing tap or a new one and removes the need for regular internal maintenance. """

Obviously have them (main contractor or otherwise) to confirm in writing they will 0% rate the work prior to instructing them. It can be extremely hard to get them to retrospectively remove VAT from an invoice, and if it's for labour or professional services (anything other than materials) there's no HMRC reclaim process

Not sure it's been mentioned but the design will also depend on the heat pump make/model. If it's a basic one with little to no modulation (maybe not even inverter driven?) then a buffer tank is much more likely to be needed. Also in Malta I think PV makes much more sense than ST and you can use PV for cooling, and to drive DHW heating via the heat pump can be a good choice depending what you're paid for energy export vs import

Plug a computer directly into the VM hub via ethernet and do a speed test. If that's okay but it degrades on WiFi, you know the VM hub is not the limit

I'd do both. Some mesh network APs have the power line adapter for backhaul built in. E.g.. https://www.amazon.com/TP-Link-Deco-Powerline-Replacement-P9/dp/B081ZWJ6FX

This. Ours signed off a raft foundation for the extension, and only after it was dug changed his mind and wanted strip foundations deeper than original and tied into the old dug out. The excuse was "because of soil conditions" but when challenged he agreed they were basically as good conditions as could be hoped for and there wasn't any other ground that could have changed his mind. I.e. he never properly looked at the submitted plans thinking he'll just decide after they're dug. Cost of£5000+VAT in unnecessary muck away. But I did gain +100mm of extra floor insulation for it.

Yes, in slab sensors are largely pointless for control purposes, my suggestion to put them in is purely because they cost nothing to add now but impossible to do later. I use mine mostly for logging/monitoring/diagnostics. It's nice to to see how warm the slab in each zone is getting, especially if you have fancy floor finishes or zoned controls and what to confirm how it's working. I do actually have mine set as an emergency shut off for the pump if the floor does get too hot. Also I can use it to dynamically control flow temp to eek maximum value out of overnight cheap rate (run a very high flow temperature initially and then back it off as the slab warms). But these are really not things I thought about until a couple years after the build. Don't worry about using slab sensors on day 1