jack

I think this is how US central heating often works - large bore ducts distributing lots of hot air. One issue is that if you're using your MVHR at high rates, the efficiency drops dramatically (not to mention the increased energy consumed by fans to move that much air - not sure how much the reduced resistance of large ducts helps). [edited to add:] I can't find it, but I'm sure we've dicussed a system where you have large-bore ducting internally, with a central connection to a smaller-bore MVHR system. The large-bore system distributes heated/cooled air, and small proportion of it is constantly exchanged by the MVHR component. Sounds like a recipe for complexity and extreme air drying, but it could work. You also need to think about duct insulation and condensation if you're cooling using internal ducts. I cool our downstairs (polished concrete) floors like this and it's remarkably effective. It also doesn't dry the air like AC can. Upstairs isn't cooled though, and I do wish we'd planned for a way to keep the bedrooms, in particular, a bit cooler. I think if I were doing this again, I have tiled bedroom floors that are cooled in summer and covered with rugs in winter - not sure I'd bother with much or maybe any warmth in winter. Best of both worlds.

MVHR isn't very good at moving around bulk heat. Cooling one room will have some impact, but isn't as effective as cooling a central air where the "coolth" will be distributed more widely as a result of air currents. You don't want summer bypass on when you're trying to cool the house on a hot day. The effect of summer bypass is to take the heat exchanger out of the MVHR circuit. If you have an air conditioner running inside the house, you'll just be ejecting any cool air you generate. Summer bypass is only useful when the air temperature outside is closer to your desired internal temperature than the current internal temperature. Think cool night following a hot day, when the inside of the house is 24 deg and it's 16 deg outside - in that situation, you want to encourage the (cool) outside air to replace the (warm) inside air. This is achieved by turning on summer bypass, which stops the incoming (cool) air being heated by the outgoing (warm) air via the heat exchanger. During the day, however, if it's 28 deg outside and 21 deg inside (where due to aircon or insulation), you definitely don't want summer bypass on.

Meh, it's alright when it's a fun one like this. From memory, the only objection we got to our proposal to knock down a tiny bungalow and build a large house was from our local parish council. It was a generic "doesn't fit the streetscape" objection without reasoning, and was (rightly) ignored by the planners.

Agreed, although be careful about knock-offs. We ordered a sample from one place, which was fine, then ordered three more, which arrived as slightly different (and unpleasant) colours, complete with overspray and crooked welding. After years of looking, thinking and procrastinating, we ended up going for Ercol bar stools in black: Not cheap, but we got them locally in a sale. I've been amazed at their durability. The paint still looks brand new, and they remain rock solid despite the best efforts of our teenagers.

When I proposed doing this, the supplier I got my Brink 400 from said that there was something special about the switch. I was convinced there wasn't, so refused to pay extra for one. As it happened, it came in the box anyway. I fitted it 5 years ago with grand plans to do something more clever, but in the end it just hasn't be necessary. Didn't fit the humidistat I paid so much for, either (although that was because some clod-hopping painter somehow managed to stand on it and break it, despite it being on top of a box out of the way). It's been fine without. We get a little condensation after showers at this time of the year due to not having heating in the bathrooms, but that clears within an hour or two without boost.

I know about that building regulation, although it was completely ignored by our BCO, incidentally. My (obliquely made) point was that if the BCO believes a regulation is not being met, he/she should point at the regulation rather than making inane comments like "there might well be a problem if he intended to store suitcases next to a hot water pipe".

It depends on how loud the unit is. Our Brink Excellent 400 is in our pantry, which is off the kitchen and doesn't have a door. It's boxed in with simple kitchen-type doors without any attempt at sealing or otherwise soundproofing them against noise. You can't hear the unit at all when it's on low (about 25% power). You can hear it on boost, but since I only manually use that now and again, it's actually helpful being able to hear that it's still on so I remember to turn it off! It isn't an offensive or intrusive noise - just a low level background roar.

What pipe and where? And to which building regulation is he referring?

From the installation instruction manual for my 5kW Aquarea model (WH-MDC05F3E5): I interpret this as suggesting a buffer tank is not required. I believe there's a small internal buffer in the unit, hence the use of "additional" here. And the troubleshooting section says this: I assume "is used" is a typo for "if used", which again suggests that a buffer tank is not compulsory. As an aside, the (Panasonic-authorised) engineer who fixed mine suggested that a buffer tank was desirable irrespective of what the manual said.

Does the installation manual say that a buffer tank must be installed? Or just that it should be? If you can find something in the same manual saying that it's only needed if less than 50L system capacity, I don't see how they have a leg to stand on. Even if it's an installation fault, isn't that the whole point of them requiring that you use an approved installer? What does the warranty say about the installation, if anything?

That's exactly the situation.

I just checked and the cheapest we were able to find it was £380. No idea why it's so expensive. I spent some time trying to find a generic substitute at the time, but from memory, it's a proprietary part.

Interesting. We had a water pump problem with our 2015 Panasonic Aquarea ASHP about 3 years after installation, and it needed replacing. No extended warranty as it wasn't installed by an approved installer. The part cost was a ridiculously high proportion of the unit. I want to say it was something like £400 for the pump, when you could buy the entire ASHP unit new for around £2k. Who was supposed to back the warranty? Generally I'd have said that was the manufacturer. Also, if it's anything like ours, the requirement for a buffer tank is set out in the installation manual. For ours (5kW), I believe it was needed if the system volume was less than 50L. If you meet the system volume requirement, I'd have thought Panasonic doesn't have a leg to stand on. Even if you didn't, I don't think they can hide behind the installer. What does the paperwork say - was the warranty in writing?

I have the same build system as @Bitpipe. When the contractor who we engaged to put up backing boards (and install brick slips onto them) turned up for their first morning onsite, they realised that the studs behind the panelvent weren't spaced at convenient 400 centres. No idea how they'd missed that when pricing the job, since it was pretty clear. One possibility was to cut the boards so that they fit the spacing that was there, but that was going to be a mammoth task. Probably more than 80% of the boards would have needed some form of cutting. In the end, we decided to go with counterbattens. Vertical battens were installed along the stud lines, then horizontal battens were installed on top of those. Fixings for the horizontal battens go through both battens and into the stud behind the panelvent. I do have some concerns about the potential longevity of this approach. There's the odd bit of fine cracking along the mortar lines of the brick slips, but other than that it's mostly held up for over five years. I think with some care it could potentially be an approach that would work with renderboard.

I couldn't disagree more.

The post you quoted referred to the UK/England, which are political bodies, not people. It also didn't use derogatory language.

Bit late to this, but I believe building regs requires you to have an unsoftened outlet (and maybe even requires that to be in the kitchen). I drink softened water all the time (bathroom tap) and it tastes fine to me.

For sure, but I don't have any way of measuring that!

Mine's hard to work out due to the 8.5kW of PV on the roof, but looking at the two meters, covering almost exactly 5 years: Electricity: 35598 kWh (= around 7100 kWh/a) PV: 37583 kWh (= around 7500 kWh/a) House is 289m2 If I assume we used all generated energy locally, that's 14,600 kWh/a, or about 50 kWh/m2/a If I assume we used none of the generated energy locally, it's roughly 25 kWh/m2/a The truth is probably somewhere in the middle. We don't try that hard to time our usage of electricity, and my wife's a massive user/abuser of the dryer (which at least is a decent condensing model), so on balance I don't think the numbers look too bad. I did look into this a while ago and I seem to recall that our feed-in tariff payments just covered our electricity bill. One day I'll get around to measuring how much of our generated PV we self-consume.

We've been in five years next month and I still see the flaws and challenges virtually every day I live here, although I worry about them less as time goes by.

Amazing work. You must be overjoyed. And can clearly take a joke.

Yes, I have, and yes, you do. From memory, when I unboxed it there was a separate piece of paper with instructions for unlocking the cooling mode. Somehow that went missing, but I was able to find it by searching online. I didn't save the link or the info, unfortunately, but I'm pretty sure you just need to get into the service settings, and it's a simple on/off setting. As I guess you know, the terminal is just an input to allow a thermostat to call for cooling. You still need to enable it in the settings.

Yes, I think we do, but I've not had anything to do with its tracking unfortunately.

As mentioned earlier, there's a massive difference in usefulness between a steam oven and a steam combi oven. We were talked into the [edited:] former latter by friends and family who use there's all the time, but ours is hardly touched. It does make boiled eggs and steamed puddings very easy, I'll give it that. I also don't doubt that there's a lot more we could be doing if we bothered making an effort and learning what it's capable of.

What a saga - great to hear it paid off in the end, and well done for sticking to your guns.