joth

We had Wunda do all the design and supply, so I personally have no idea! There's loads of discussion on this forum about it, I've seen links to software packages that will do it, but it was one area I was happy to keep my nose right out of. Hopefully someone else will chime in with more useful guidance.

Have you had a loop design done? I requested 4 zones but the design came back with 9 loops, to my surprise, so spending time debating 3 vs 4 zones maybe moot if they'll split it to more than 4 loops anyway. Also, it took us several weeks to iterate and finalize design, then more time to get parts, and several days to install the loops, so I have to say if you're pouring screed this week you need to get a proper wriggle on. Good luck!

Hope you installing 3 phase, and got enough space for a serious outdoor heat exchanger. Over 30kW of cooling? on a UK domestic home sounds insane. https://www.orionairsales.co.uk/daikin-air-conditioning-rooftop-packaged-uatyq30abay1-heat-pump-30kw100000btu-415v50hz-10214-p.asp

Dunno about "latest" shortage, we had a 4 month wait on our fridge last year. I think this is just the new normal.

To caveat my suggestion, I'd say the Tempest weather station itself is so-so. Very clever design, except it's made in California and has unrealistic expectations about how well a solar-powered only device can work in our winters. And their silly wifi bridge seems unreliable and need a periodic reboot. If the station itself had the option of PoE it would be much nearer a strong recommendation. The lifetime subscription to their cloud API for forecasts is nice though (at least until they turn that down...)

I've got a weatherflow tempest, and the loxberry integration for it works very well providing weather forecast off of the tempest cloud API, as well as live readings from the weather station itself. No recurring charges Very helpful info on the rest of your setup! I had intended to circulate UFH in this way (also copied the idea from Jeremy) but so far haven't found it necessary, as the UFH is only on the ground floor and that's almost all open plan and solar gains very naturally convect through the building anyway. What I really could use is a way to redistribute overheating from upstairs back down into the slab, but that would require another (water to water) heat pump

This summer was peak tinker, especially before lockdown eased. I think my wife was looking for "Loxone Widow's" support groups at one point.

Yeah exactly. We have 9 UFH loops, so I have 9 salus autobalancing actuators sat in a box in case I can ever be bothered to install. I've modelled downstairs as 3 rooms with 3 Intelligent Room Controllers in loxone, but they all drive Call For Heat onto a single heating/cooling controller that drives relay for the downstairs zone call for heat on the ashp controller. Having 3 IRCs means I can have different cooling profiles for the areas under automatic rooflights, and also can set different target temps based on different schedules and occupancy per room. But that's just me tinkering in the loxone programmer because it's a bit addictive. From a systems point of view it's just one room stat calling for heat on one big ashp UFH zone.

We have a skylight at the top of try vaulted ceiling over the hallway (3 story void) and a rooflight on the ground floor extension flat roof. I open the skylight to an increasing amount based on the difference between actual and target internal temperature, and when that's beyond 10% open I also open the downstairs rooflight. For whatever reason the skylight supports setting an exact % open position whereas the rooflights are either 0 or 100%, hence this algorithm. For bonus points I calculate an "overheating risk" based on tomorrow's forecast and whether we overheated in the last 18 hours, and if so set the overnight target one degree lower as a sort of cooling "boost" mode. Finally, it all locks out closed if it's raining, rain forecast in the next hour, or if it's hotter outside than inside. I tried to also make interlock so that the LED strips around rooflight won't come on when they're open, to reduce fly attraction, but I found in practice we didn't get flies in anyway this summer, fortunately. Fly screens would be the other solution!

This is very much like my setup. One other thing I've found is that while I do use the Touch temperature sensors to control automatic shading in rooms with a tendency for overheating in summer, for the whole house temperature I've found it even better to use the MVHR "indoor temperature" sensor as the guide. This is effectively a ready made average of the entire house temperature so extremely simple to use to guide heating / cooling. Automatic roof window opening at night time, for stack cooling, is probably the single biggest utility of the entire loxone install, somewhat to my surprise as I only added it as an afterthought. It's incredibly effective, and again I use the MVHR "outdoor temperature" sensor as a very reliable guide as to when stack venting will be useful to enable. (the MVHR "bypass status" would also be a good signal for this, as it ensures that the mvhr and heating/cooling are not in danger of fighting each other)

Option 3 for me, with some caveats 1. The UFH manifold does not have any zone actuators. They are sat in a cardboard box waiting to be installed. For now, the whole ground floor UFH comes on/off together. (Likewise the upstairs FCU) 2. I used Touch, not Touch Pure switches, and just for the "main" switch in main rooms, so about £500 How well insulated is your house? Will you need zone based control? Do you actually like the Touch [Pure] switched to use? Are you okay having to (repeatedly) explain them to every house member and guest? I think those are the main questions I'd ask to guide a design. At the moment my loxone-> heat pump integration is just a couple relays on the two zone "call for heat" inputs. (UFH and FCU). While loxone programming (which I do myself) is needed to adjust details, a future owner could easily unhook the two and use the Ecodan room stat instead. If I do install the manifold actuators it'll probably be just for the self balancing feature, but if start using them for more fine grained control of the downstairs loops it will definitely entangle loxone into the heating system a lot more. Loxone also controls skylight opening for automated stack venting, blinds, boosting ashp when there is cheap/free electricity available, towel rads, electric UFH in the ensuite, MVHR boost, and putting stuff into eco mode when we're away, so I appreciate having all that logic together with a single system acting as source of truth for what should be happening

Yep ecodan supports it fine, just a dip switch and a bit of fiddling in the controller menus. (and for me, messing around in the loxone program) To be generous to installers, when they say it's not supported they may not be referring to the ASHP or RHI, but just the lack of gap-free insulation they applied to pipes, pumps, valves etc which will guarantee puddles of condensation everywhere. A system has to be designed and installed with cooling in mind if it's going to be usable, and our UK installers are just not trained to do this. Nor do they seem willing to charge a premium for the bit of extra effort this takes.

I have one of the emonpi devices, which is similar. Easy to get going but a bit frustrating all in all. It only sends power reading samples once per five seconds, ok for hour by hour monitoring bit a a bit lethargic for real time control of PV redirect etc. OTOH it's all local not cloud based, otherwise it would be far worse again.

"Energy throughput" is called Power and is measured in Watts or kW, not kWh. (Just saying, as someone was bound to) I think of it as the battery is like a water butt with a very small constrained outlet tap. If you get impatient filling a bucket from it, and fill it from the (expensive) mains-fed hose at the same time as from the ("free") water butt, then it will use less volume from the butt and thus not get as much usage from it as anticipated

Have you put your details into PVGIS? https://re.jrc.ec.europa.eu/pvg_tools/en/#PVP

Yes it's called the Smart Export Guarantee now, much lower rates, see league table below. You need an MCS certified install to qualify for payments. https://www.solarguide.co.uk/smart-export-guarantee-comparison#/

Well it's a loss of efficiency, which could become an issue if there's too much

To clarify, I'm definitely not suggesting delay the ashp to make a financial saving, I'm saying give up on trying to install it by March to achieve a massive stress saving. Unless you have a tame MCS ASHP installer in your pocket that will work exactly to your schedule, my experience was whatever you plan, they'll work on a very different timescale.

Depends entirely on what solar gains and other heat sources are in the building. If it's a dark cave with one inhabitant, probably not, if it's a greenhouse containing bitcoin server farm and 5 people then some active cooling will be necessary. Also, how happy are the inhabitants to sleep with doors and windows open. I don't believe MVHR ventilation rates would ever shift enough air to keep even a single bedroom cool indefinitely. The heat output of one bed-bound human is greater than that which one mvhr outlet alone can offset . The most effective cooling in our house is automated stack venting via skylights. The ashp+FCU is very useful, mainly held back by poor sizing fcu for the ashp, resulting in a lot of short cycling. I will add a larger buffer tank at some point (and probably another fcu) to balance it out. A dedicated A/C would definitely have been more effective, primarily because it would have required me to pay for professional design and installation of a fully specified system. As it was I just slung in an fcu and pipes on the offchance it was useful, and not finding it is, I'm on long haul project to upgrade it to get it to full potential. If UK ashp installers were used to design + install of cooling systems it would be very different matter.

Correct, but even this summer my MCS installer still thought it triggered the "metering for payment" clause though, so wouldn't enable it. (I enabled it myself) My point being with the end of RHI hopefully they'll get over it and start designing systems to customer needs, rather than RHI needs. (I'd be fine if he'd charged a bit more for cooling. The extra work on completely insulating all pipes, pumps etc and getting condensate drains in isn't zero effort)

Do you planning to have a backup source for heating and DHE? (E.g. immersion heaters in the buffer tank and UVC) If so, maybe just leave the ashp until later next year. No doubt there will be a panic buying in the lead up to March with price increases, supply shortages and substandard rushed installs . Late summer there could be good discounts available as installers try and drum back up work, and in addition you won't be beholden to RHI constraints so might get a better end system. (e.g. if cooling is required, installers can't use the antiquated RHI excuse to not enable it) If your house is well insulated you won't need heating until October, and many here muddle by without an ashp for one winter (or indefinitely)

I assume you mean to share one inverter between both arrays? The main constraint is the distance from array to inverter. This is high voltage DC cable, needs armouring if not left fully visible. Too long a run will cause losses, especially if it's on a short "string" of panels (which means lower delivered voltage, hence line voltage drop takes a greater proportion of the output). In general Voltage drop can be minimised by using thicker core cable, but MC4 connector limits how far you can increase PV cores. Ours is about 10m, from house roof to garage. What sort of distance are you thinking?

I'm struggling to understand the page but isn't that just the battery (as in, stack of cells), and you need to add an inverter to the price Compatible inverters: Growatt, Victron, Goodwe, Kehua, Solax, Voltronic, Studer, Sermatec, Solis, sofar, Voltacon, total of 16 brands If it could be DC coupled to my PV inverter (SolarEdge) it starts looking interesting

I was skeptical too, but the Bora Pure X with recirc has greatly exceeded expectations. It has a built in dishwasherable filter that does really well, I've never yet found any grease on the under plinth gap in expels air through. (It blows out across porcelain tiles and we have a weekly house cleaner, so maybe they just keep on top of mopping it well enough we have never seen any build up). YMMV! If you have a plan to extract to outside with an airtight damper when not in use, and solve the issue of where the inlet air supply comes from to balance it, then fair enough, but that sounds a lot of extra cost and faff where the recirc would work.

The in-hob extractors are typically equidistant from all four "rings" on the hob, whereas the pop-up ones have to be on the far side of the hob, making them too far from the front 2 rings thus much less effective One more thing to add:- If doing an airtight build and/or with MVHR, you should plan for an internally recirculating downdraft, not one ducted to extract to outside.