Dan F

Hmm, I was wrong. My blinds appear to be PH certified! https://database.passivehouse.com/en/components/details/shutter/romawiegand-modulo-p-0254rs03. Looks like this is about the window head detail more than anything else.

These look good! Do they supply direct in the U.K. or via resellers?

Do you definitely want shutters and not venetian blinds? Our blinds are venetian, but close better than most venetian blinds meaning that once closed they look much like shutters and block out most light. Being able to adjust them to block direct sunlight but allow reflected light is also invaluable in the summer to minimize solar gain, but still be able to see out of the windows. External blinds/shutters, given they are outside the building fabric itself won't ever be PH certified. The use of blinds/shutters however can be used in PHPP for modelling overheating. If possible try to get your blinds/windows from the same supplier and installed by the same person.

What would you use case for this be? Personally I put two AOC cables in: 1) One between TV cabinet and potential projector location. 2) One between a poential "frame" TV on a wall in the living room (which doesn't thave a cabinet or anything) to a remote cupboard. One I was recommended were these. Not used ones we have installed yet though. https://cleerlinefiber.com/product/hdmi-active-optical-cables/ https://www.wyrestorm.com/global/aoc-cables/

Yes, assuming compressed 4k. IPlayer/Netflix streams currently use up to around 24Mbps whereas Cat6 supports up to around 9000Mbps. So, even if streams become less compressed over time there is still a ton of overhead. The difference betwen Cat6 and Cat6a is maximum distance supported at 10Gbps. Uncompressed 4k or 8k you primarily need to think about being blu-ray, ps4, reciever ->TV and you should use HDMI (AOC is required for length) in these cases. Uncompressed 4k or 8k coming into your house is a long way off, but if you wanted to future-proof for this you'd want to plan for 40GB or ideally 100GB fibre links everywhere.

Depends what you mean by "full rate". The uncompressed bitrate for 8K HDR is around 48Gbit/s and and even 4K HDR is >10Gbit/s, so technically CAT6 won't support these bitrates. No. See https://www.truecable.com/blogs/cable-academy/know-your-cable-cat7-ethernet You could. What make most sense IMO is to run unterminated fibre for future-proofing but not pay to terminated it until you need it. Or you could install pre-terminated cables from somewhere like https://www.fs.com/. If you buy fibre need to look for multimode (OM3, OM4 isn't justified and costs more) and you'll also want something with mutiple fibres to support throughput. Should be available for around £1/m. If you are only concerned about 1-2 locations where video source and dispaly won't be next to each other, then the best solution may be to install HDMI AOC cables in these specific locations. These are available up to 40m long and support 48 Gbps. That said, I agree with others that we are a long way off 8k 48Gbit/s video steams being widely used. Netflix 4k UHD steam is only around 18Mbps today!

The PHPP numbers are simply the values from the PV datasheet. As such, our PHPP has the details of our 365W panels which were high mid-range two years ago. If the value is 268W then there is nothing conservative about this, either there has been a mix-up or these are pretty bad and/or old panels. They are sligtly smaller than most panels (typlically around 1050mm x 1750mm), but not by enough to make 270W sound very reasonable in 2022. Are these panels already on the roof? Can you ask them what panels they are using and why? Did you get a quote at any stage?

There are multiple suppliers of "heat batteries" for cooling MVHR incluing Zehender and Veab, but cooling via MVHR provides very low cooling output. See: https://www.greenbuildingstore.co.uk/can-an-mvhr-system-be-used-for-cooling/

Domus just resell multiple different Italian and Spanish brands at crazy prices. You can buy the same tiles elsewhere at a lot less. When you buy toilets and taps you buy Geberit or Grohe etc. and you know you are getting and can easily check prices are competitive. With porcleain, most suppliers rename and put they'e own markup!

No, I don't think you can do that. 1.5bar. 2bar or 2.5bar dyanmic pressure (or whatever you have after losses) will give different flow rates through a shower mixer+head than just out the end of a 15mm pipe! Aside from the theory I know this from practical experience as, when I was trying to work out why I only got 7-8L/min from shower, I took the whole mixer body out and then measured the flow-rate (using water meter on cold supply) and it was a lot higher. I also flooded the bathroom!

Yes, now set to 3.5bar and this helps. But doesn't negate the almost 1bar of loss those runs have (0.4 due to elevation and 0.6 due to pipe), so shower still only gets around 2bar. This translates to a satisfactory flow rate of 10-12L/min, but not quite as much as I'd expexted.

OK. Some of ours were 16m away and flow rate isn't great (even with new 32mm main). We also used 16mm MLCP. It may be partly down to the showers we used, but the fact dyanmic pressure after PRV and water softener is <2.5bar doesn't help either.

This graph is from the PassivLiving MMSP package which was installed as an extra as part of install. I use eeBus for controlling heating in the winter based on slab/room temperatures and tariffs, really annoyed that I can't control cooling via EEBus though. I don't have any ebus hardward and haven't tried this yet. It's on my TODO list though, as I really do want to find a way to control cooling, if possible. Vaillant promised a Modbus interface, but nothing exists yet 😞. My only concern with ebus is I haven't seen a coprehenisve list of registers/commands for arothem plus anywhere.

15mm copper of plastic? 15mm hep2o is only 11mm ID and, depending on how far away your showers are and what flow rate you want.. might be tight. It's one thing If your showers are close and/or you are good with 8L/min, but if they are 20m away and you are expecting 15L/min, you need to size accordingly.

This isn't the case. You can use a 3-phase hybrid inverter with a single battery, or a mains-coupled battery on just 1 battery. With the correct inverter (this may be bit more expensive, agree) it will export on L1 (from battery) to compensate for loads on L2 and L3. You don't have to. Could have house run on single phase and only use 3-phase for PV and battery chargers.

We used a black high-density acoustic soild pipe which supposedly helped avoid "flush noise" given we have 3 first-floor waste which comes down internally in the ground floor. I don't know how much real difference it made though. One of them still made a lot of noise and we ended up wrapping it in a specialist acoustic pipe wrap which made a very big difference. You don't need pans, but ideally you have frames in. The waste height will depend on height you want toilet at (frames are adjustable), but datasheet will give you standard height. 23cm it seems.

I actually bought the Mixergy Modbus interface to enable me to do all control locally without a cloud dependency, so it is very doable. The installer commissioned it with the standard controller though and I haven't got round to fitting the Modbus controller yet. That said I haven't found using the control or app to be complex at all (simpler than stting up and interfacing with modbus anyway) and if connectivity is lost everything (apart from the app of course) continues to work locally without an issue. What the controller app allow you to do is: - Set temperature (which you could easily do in your ASHP controller too) - Set target charge level (this assumes partial charging via top coil or immersion heating) - View graph of top/bottom temperatures and % charge. - Setup schedules (which you could easily do in your ASHP controller too) The smarts (which I haven't tested yet because I turned it off fairly early on for some reason) is allowing it to automatically decide when to heat the tank and to what charge level and temperatue based on, supposedly, the your usage patterns and tarrifis. Aside from the PHE (which uses a pump) and enables, according to them, a more effective us of the tank capacity it is still a UVC under the covers, so while not the simplest of UVC's it's still simpler than something like a Sunamp IMO. A good part of the value IMO of the Mixergy approach is the partial charging story which I bought into and plumbed for. While this works great, what I've realised is that heating a UVC in this way, while possible, is not efficent and I really need to switch to the PHE and heat the whole tank at once. This is because you are constantly needing to provide a 60C flow temp, ramp than ramping up from 10->60C as the UVC heats up. There are other avantages of Mixergy aside from this though. This is spot on. Excellent summary of my various posts 🙂 We did find coding resistor available for £5 online though which someone bought and is using. To clarify, if we had UFH in a screed above insulation then standard Vailant controls would work great for cooling. The problem is that, as our UFH pipes are in the slab it self the very slow reaction time means the the Vaillant controller acting as a thermostat doesn't suffice. The controls are there and work, but in my case (as with others with UFH in slab) you really need to control UFH based on slab temperature is posible.

Yeah, Octopus don't care. It's the DNO's who typically give permissions that say "0kW Export" for battery systems. They have no way of knowing if the expot is from PV or battery in practice though (assuming PV is approved). That aside, who has a battery system that allows them to export to grid from battery at will?

You can do this if your battery storage system lets you (although you technically shouldn't). Do you have a battery system that let's you do this though? Majority don't AFAIK.

No, Agile Outgoing still available AFAIK. https://octopus.energy/outgoing/

How would you do this? - You can't use Octpus Agile Outgoing with Octupus Go/Intelligent. (That said, I am paying 28p import (Flexible Octpus) and Export is paying up to 80p last couple of days) - DNO permissions typically don't allow for export from batteries, only from PV generation. Most battery systems don't have this option either.

Depends on size and layout of your kitchen. Ours has 2 extracts over the kitchen island (to get require extract flow rate) and a single supply in a connected breakast area. Most MVHR designers will calcualated required door undercuts based on flow required between rooms.

Tesla have moved to li-ion for 12v now, other EV manufactuer may well follow. Lasts longer and an EV doesn't the amps that a starter motor requires.

It's not grey in the sense that the DNO permissions clearly states "0 Export" on it. The 3-phase balancing is still zero "net" export, but yes, the Tesla tariff breaks the rules. I guess Octopus must have some kind of DNO permission for this. Paperwork aside, if you have approval for your PV to export 5kW and your G99 approved inverter is setup to export a maximum of 5kW (battery+pv) at any point in time, I don't really see the issue or know how anyone would know. You can't make Powerwall export at will I don't think, but I think you might be able to do this with some other solutions. Today would be a be a good day to do that given Octupus are paying 75p for export later today!!

I was quoted £14.5k+VAT in Janurary, but this went up to £18.5k+VAT in June (including gateway and install). You can use them in a power-cut. You need DNO approval. PW's won't export to the grid, only cover loads. (although in 3-phase setup, using the gatway, it will export on one phase to compensate for load on other phases).