Jolo

Thanks for the tips! The unit goes in a cupboard on the first floor, the difficult bit is the Dutch stairs, which can be more like ladders than anything that would be called "stairs" in Britain. (Though lots of people here have their washing machine in the bathroom which is usually upstairs, I've no idea how they manage it...) However, I went for a Duco Energy Comfort 325 in the end. It seems like a good choice, I like the programming menus, and as it's over-sized for our house we'll end up running it well below capacity, which should be good for efficiency and noise. Although I think I might be cursed -- the first one that arrived had been opened before, and the unit was covered in scratches and paint blobs... so they're bringing us a replacement tomorrow. This will be our fourth MVHR unit since August, hopefully the last!

Oh that's interesting, I've heard differing opinions on the need for a pre-heater. It was one reason I went for the Flair instead of the Ease. We did have several days below zero this winter, but I thought the pre-heater was only really needed below -7 or something? There's a separate external pre-heater available for the Comfort, and there's version called the Premium which has one as an option.

I think I will go for the DucoBox Energy Comfort 325 as it's available now, and is light and compact -- and as its capacity is so much bigger than our maximum, surely running it so slowly will get amazing heat recovery? Also what I wrote last night about the Duco wall-mounted controllers is incorrect, the three ventilation positions can be adjusted (I found it in a separate manual, which goes through all the options in detail). So that's good. Out of interest, I wonder what people's thoughts are on the Itho Daalderop HRU 200 ECO. It's an absolute bargan basement option, available for well under a grand in either Euros or Pounds. I'm amazed at the price! The volume setting is done via two potentiometers, one for low and one for high, the middle speed is just the average of the low and high. https://www.ventilationland.co.uk/en_GB/p/itho-daalderop-hru-200-eco-unit-e-rft-high-rise-200m3-h/9947/

One big reason for choosing enthalpy was the lack of a convenient condensate drain point, but I feel up to tackling that now I discovered the drain pipe saddle clamp things...

Thanks everyone for your input, much appreciated! I'm baffled too, as is the distributor. And I chose Brink as they're well-known in this sector, been around a long time, manufacture in NL and sell globally, and they're part of Ariston. But their customer service has been very poor -- they don't respond until they're nagged, go silent for weeks, they've even ignored repeated emails from the distributor, and apparently told him it was sorted when it wasn't. It took them two months to get around to testing our first (returned) unit, and even then it was only because I'd emailed one of the executives at Ariston out of desperation. They said it met all required norms, yet every house guest who's been willing to try it has scored full points at a game of "guess the odour". Even their installer who came could smell the problem. I've offered to help test it, told them they can send someone whenever and I can demonstrate the issue in 30 seconds. Part of the problem is that we self-installed, so from their side it's the distributor's problem, but he just runs a small ventilation business and whatever commission he made from the sale will have already been eaten up in the time he's spent dealing with this! If he was based nearby he'd probably have come round to smell it for himself, but that hasn't happened as he's almost an hour's drive away. Now I'm thinking about it, I'd have been happy to pay for a visit to test it. Even after all this, if there was a solution offered then I'd rather keep the Flair (or switch to an Ease) than go through the hassle of swapping it out, but Brink seem to have little to no interest in engaging, so sadly I'm out of options. 🤷‍♂️

As mentioned in other threads, I've sadly lost confidence in Brink due to the odour issues I've had with the Flair 200/225. So I'm having to dive once more into the world of MVHR units, and I'm drowning in research now 😵 my head is just swimming with it. I was going to splash out on the Zehnder Q350 with enthalpy exchanger but then I noticed it's almost 50kg, which will be a total pain to install. (I guess I could take the exchanger out to get it upstairs and on the wall...) I do like the look of the DucoBox Energy D325 (and it's smaller sibling the D250, which isn't available until April), but the four-button wall-switch will apparently only do 10%, 50% and 100% of the maximum speed, and that can't be changed?! (Having a 10% flow button seems really strange to me, especially as there's a separate holiday mode. I'd much rather 30% 70% and 100%) I've also just learned that many models of MVHR don't have constant volume regulation, which I think means that the m³/h you set is just a hopeful target, and it will drop over time, which seems a bizarre omission to me. So... does anyone have recommendations, suggestions? (Or brands/models to avoid!) Our house is less than 80m², and the calculations based on Dutch norms came out at a top flow of 175 m³/h. Nothing fancy going on, a very simple set-up really!

Sure! It never worked properly, as there's a leak inside the unit. This means any smells/moisture are just distributed around the house. I've been posting about it here, hijacking an old thread on the same topic, from about halfway down the first page. The ordeal still isn't quite over, I'm waiting for a collection date and refund at the moment (though the distributor has agreed to this). It's a shame, as I really liked the Flair and chose it after a lot of research, but I can't live with the cooking (and worse!) smells being blown into the bedrooms all the time. (I've been closing the vent into the main bedroom when we cook, the transfer is that strong.) If you decide to go for a Flair anyway then maybe yours will be fine, but I advise you to test it straight away. It's fairly easy to do -- just have someone waft a bag of ground coffee or squeeze the air out of a half-full bottle of shower gel near one of the extract valves, and see if the smell comes through one of the supply valves. I'd be very curious to know if anyone else has the same issue we have!

Thank you John! So these units are just missing some logic which adjusts the fan speed depending on the pressure, is that right? BTW I was considering getting a Zehnder Q350 with enthalpy exchanger, but then saw it's almost 50kg!! The Duco 325 is only 21kg, that might be a better option... Both seem to have constant flow, at least!

I'm currently researching options to replace my faulty Brink Flair 225, and have found some which apparently don't have constant pressure or constant volume, which seems bizarre to me. So without that basic feature, if I set the normal flow to, say 100 m3/h, it will drift over time as filters become dirty? Here's an example of one: https://www.ventilationland.co.uk/en_GB/p/vent-axia-mvhr-sentinel-kinetic-advance-250sx-including-preheater-right-250m3-h/9985/

Somehow I missed your reply when you sent it -- but thanks for this confirmation, Dave! What you describe is exactly how I expected the system to work, and also how it's marketed -- but our Brink Flair unit doesn't behave this way at all. Any smell in the extraction rooms is immediately blown into the supply rooms. Out of interest, what system do you have, and would you recommend it?

Great question -- and one which I've been pondering a lot, so any input is welcome! The main benefit of the enthalpy exchanger, besides not drying the air out, is that there's no convenient drain point right now, so it felt worth the extra price. While the main house drain passes directly beneath the MVHR cupboard, there are two concrete floors in between them, and that was putting me off it last summer! But adding a condensate drain doesn't feel too difficult now I've discovered those drill-patch-pipe things that just clamp on. The enthalpy exchanger options I've found are mostly Zehnder, a few units in the confusingly broad ComfoAir range, which are a few hundred euros more expensive than the Brink we have. The Q350 for example. The main down-side of the Q350 is the size, it's got a maximum airflow of 350 m3/h, which is much larger than we need, and so the unit is physically larger, although I think would just about fit in the MVHR cupboard with maybe 15cm space on each side. It's also a lot heavier at 48kg, so I'd be tempted to get an installer to fit it. The upside of that unit is that, as our top airflow is 180 m3/h, and we typically run it around 70 m3/h, we'd always be running it very slowly, which should mean it's super-efficient. For non-enthalpy units, having looked at other brands, Zehnder is of also a popular choice there, and they have options which cost less than the Brink we have now. I also quite like the look of the Duco Energy Comfort units, they've just introduced a 250 m3/h unit which would fit the bill, although I can't find it listed for sale yet. https://www.duco.eu/uk-ie/products/mechanical-ventilation/ventilation-units/ducobox-energy-comfort

Agreed, it can only be something such as a design issue or manufacturing flaw. Either way, I've sent the legal email cancelling the purchase contract due to defective goods (and it's been acknowledged) so I guess legally it's Brink's unit now, and I'm just waiting for them to collect it!

Well I said I'd provide updates, but there's nothing much to update other than to say I'm really disappointed with the customer service I've had from Brink. In early December they sent an installer who swapped out the whole unit with a new one which, to our amazement, behaves in exactly the same way. I know you'll think I'm mad, but there is definitely strong odour transfer between the extract and supply ports. We tested this new unit, again just via the ports on the top (to exclude any internal ducting issues) and the problem is the same. I wonder now if Brink have a design flaw or manufacturing issues with the Flair 200/225. The technician from Brink who came checked out our ducting and external connections, and said it all looked very neat and well-installed. I also got him to smell-test the old unit, which he did reluctantly (not sure why, it only takes a minute), and he acknowledged the problem. I didn't do another one on the new unit before he left, as it never entered my mind that the replacement unit would have the same issue. I clearly trusted them too much! So I emailed the supplier and Brink, explaining that this new unit had the same problem, and they wrote back telling me they were going to thoroughly inspect the returned unit, and would get back to me hopefully by the end of December. Well it's now February, and I still haven't heard anything at all. They even seem to ignore the supplier when he emails them (at least, they don't include me if they do reply!). So I've had to send a legal email to the supplier, cancelling the purchase contract due to defective goods. I didn't want to do this, I'd much rather they fixed the issue but they just don't seem interested. I'm not sure how they'll respond to this, I hope they just take it away and refund the money, I have no trust in Brink any more.

Nope nothing like that! I'm very sure that the high humidity is because of a leak inside the MVHR unit, so there's extracted moisture being blown into the house along with the smells.

Yes, those ribbed sections are 1cm apart, so you can cut it to length. I ended up doing this all over, with good results! I even used one of the off-cuts to extend another section where I needed a longer section, joined with a regular metal-with-rubber-rings piece, as the 125mm plastic pieces fit together perfectly with the 125mm spiral ducting pieces.

You're welcome, @Mattg4321, I'm glad I was able to help Like you I was also disappointed that expensive solid attenuator I bought didn't seem to make a difference. I wasn't entirely surprised though, as the drone always sounded like it was coming from inside the green pipes, at it had the same reverberating timbre as can be heard if you speak into them. Yes I used 90mm ducting (external diameter) so the 100mm flexible silencer fitted over pretty nicely. The difference is amazing. Glad this solution worked for you too! (BTW if anyone else needs one, this is the silencer I bought, on the UK sibling site of the place I bought mine from: https://www.ventilationland.co.uk/en_GB/p/flexible-silencer-non-woven-with-connection-diameter-100-mm-length-1000mm/6172/ )

I might try this, though I'm not sure if it will hurry Brink up at all. I feel like I've dotted every i and crossed every t, and asked here and elsewhere to test my sanity!

Exactly right @Russdl and @JohnMo! I've gotten a template letter from the government's consumer authority, and I'm going to send it shortly. It gives them two weeks to repair or replace it, and if that doesn't happen then I can terminate the purchase agreement unilaterally and they have to give me the money back. I'd really prefer that it didn't have to come to this, but I don't see any other option as nothing is happening.

Yeah it's a weird design, isn't it? I'm sure I saw a bracket at one point, into which those flat bits at the top would slide. But I can't find it now. Maybe I dreamt it? Anyway, I just drilled holes in the flat bits! Also strange that the two-duct valve adaptors have sensible screw points. There's a new design which is even better, as it has a pair of screw points at the top and the bottom of the main section. Are you aware of the restrictor rings they sell, which click into the distribution box? https://www.ubbink.com/gb/products/ventilation/air-excellent-ventilation-ductwork/distribution-boxes/air-excellent-dbox-internal-air-restrictor-ring/ I used the Ubbink AerFlux online tool, and I have to say it made setting the flow up really easy, as it tells you how each ring should be configured. https://www.ubbink.com/int/advice-service/aerflux-configurator/ Although I don't know if it takes the UK building regulations into account, it definitely has the Dutch ones, which may be slightly different. VentilationLand seems to be an auto-translated version of the Dutch site https://www.ventilatieland.nl/ -- alhough it's possible that the Dutch site is an auto-translation of the German https://www.lueftungsland.de/ ! I'm not sure how it all ties together. I'm not sure how these companies work behind the scenes, it's possible that VentilationLand has to wait for a big delivery from Brink. But then some other similar sites don't seem to hold any stock of their own, instead the goods arrive from other retailers/warehouses (even though the price may be cheaper than on the other sellers' own websites!).

Thanks for the replies -- but just to be clear, it's definitely not the internal ducting, as I've mentioned earlier we've done every check possible. The extract ducts suck and the supply ducts blow. The ducting is still visible so it's easy to follow each pipe to its destination vent. We've tested with just a single pipe connected to each port on top of the MVHR unit, eliminating the internal ductwork entirely. It's definitely not external cross-flow either: We followed the supplier's guidelines, he's happy with our inlet and exhaust locations The bloke from Brink was satisfied with them The odour transfer is too strong and immediate to be happening outside anyway So the problem is definitely inside the unit, there is no doubt about that. However, my question this time was just about what the humidity should be for an MVHR unit that was working properly. Thank you John, that's good to know! Thanks Mike, that's useful information. But nothing changes regardless of the speed, because the unit is just blowing a mixture of fresh and stale air into the house. So when showering, the bedrooms and living room are getting some of the steam blown in. Not yet! This is one of the reasons I'm getting annoyed with Brink, they go weeks without any progress or updates. (Also, the odour transfer is so strong that anyone with half a nose can detect the issue. Spray a bit of deodorant in the bathroom and a few seconds later it arrives in the living room.) I'm now considering starting to send legally valid complaints to the supplier, in the hope that he'll get Brink to up their game. It's been three weeks since I let them know that the new exchanger didn't fix the problem.

Update... there is no update! I'm a bit disappointed with Brink and the supplier, to be honest. I don't get any progress unless I push for it, and there seems to be no answers forthcoming. The latest "news" is that it's been passed to the R&D department to figure out what might be causing the issue. One question for those with experience of such systems -- should the MVHR system help regulate the moisture inside the house? I ask because we've had really high moisture levels indoors, like 80 - 90% RH sometimes, which is surprising to me. Windows covered in condensation in the morning, even though we're running the unit at around 0.45ach. We're not doing anything weird like hour-long showers or running a commercial kitchen! I've taken to opening the window vents, which helps a lot with the humidity but of course defeats the purpose of the whole MVHR system!

Oops, I missed your reply somehow! It's a radial system. Small house, really simple, the ducting is mostly still visible so it's all been checked a dozen times. We've even tested it with just an elbow and a metre or two of ducting on the extract and supply ports, and the problem still exists, so it's definitely not a problem with the internal ducting.

Oh 100% Here's a photo from during our installation

Thank you @Mike that's useful info! I discovered last night that despite my best attempts to cover the metal box, some condensation is forming in awkward to cover places, so I might take the plunge and get a proper one. I do like DIYing stuff, but with the time and money I've spent on trying to insulate a metal box, I could have gotten the proper one!

Can I ask where you bought that, Mike? I wanted something already insulated, but couldn't find where to buy one! Ended up using a metal one and covering it in Armaflex, which does work but it was a faff