hauntedicecreamvan

I need to collect some more data to draw any conclusions for my property. For humidity, it is a toss-up between letting the background rate deal with it, vs boosting, especially right now where the outside air is holding a lot of moisture - in that situation, I was finding that the boost could cause whole-house humidity levels to rise more than if I just let the background extract deal with the shower spike. I think the biggest limitation of CO2 sensors is how they handle baselining of the data, and their also long-term reliability. All my CO2 sensors are "true" sensors using NDIR, but because of how they baseline based on the lowest measurements they take, you never know if they are reporting close to the actual CO2 levels or levels with a big offset. I don't know what the solution is to this, it seems they all rely on rooms being unoccupied some of the day, and supply of fresh air good enough to ensure that levels do fall to close to outside air levels. I also had one sensor fail with ridiculously high readings (measuring 2000ppm+ indoors, and 900ppm when sat on a window sill outside).

are you looking at integrating via the serial interface or just using binary inputs to trigger boost? I considered the RS232 proxy approach, with an ESP32, so that I could keep the Comfosense while still allowing HA to read/set itself, but decided it was too much added complication, so just hooked up a dry-contact relay to the bathroom switch input. It would be nice to see the outputs from the various sensors and status of the summer bypass in Home Assistant though. Probably not needed long-term. The CA180 LUXE doesn't have any onboard display/buttons, so the Comfosense is needed to set the flow rates during commissioning, but after that its all stored in the CA180 itself so theoretically could run without it (or with something 3rd party running the reverse-engineered serial interface commands). I was initially using the Comfosense schedule to set some crude time-based boost that coincide with daily shower times, but now that the relay input is configured through Home Assistant, boost logic is based on CO2 sensors in habitable rooms, an air quality/VOC sensor in the kitchen, and humidity rate of change in the kitchen/utility/bathroom - I shouldn't need to touch the Comfosense much, if at all, going forward (assuming I have thresholds set up correctly).

I have a Zehnder Comfoair 180, with a Comfosense 67/CCS controller (RS232 comms). The controller has capacitive pads under the plastic faceplate, and after working fine for a couple of months with light usage it suddenly become unreliable with missed button presses, gradually getting worse to the point that it had to be operated with the plastic plate removed, and eventually mixing up key presses or phantom presses. I swapped it out for a spare Comfosense and the replacement is working fine. Has anyone here experienced reliability issues with these controllers? It seems potentially quite fragile, being based on a flexible PCB which sits wedged between the plastic display surround and the front cover. I don't see myself interacting with it much from now on anyway, since flow rates are commissioned, and boost is controlled via the bathroom switch input by Home Assistant based on air quality and humidity rise/fall rules.

You were absolutely right. In the end I went for 2x 18mm plywood sheets with a layer of Tecsound SY100 between. Even without doing anything special between the Zehnder brackets and the plywood, just screwed on rigidly, there is zero vibration or hum, even if I set the unit to run at max fan speed.

I went for fully glazed, from Just Value Doors, who use Smart Systems profiles. Very easy to fit, and there is a small adjuster on the top of the door in case it ever needs the toe and heeling adjusting without taking the beads off. I went for 6.8mm acoustic laminate plus 4mm toughened glass which was a custom order but I found them helpful to deal with. My only criticism is that if the handles ever need to be replaced, there aren't a lot of options, because standard 32mm wide plates don't fit due to the narrow aluminium profile.

Rigid spiral type - Lindab SLXU.

Yes, 900mm Lindab inline attenuator first, followed by Comfowell attenuator manifold. Ducting is 90mm semi-rigid, with Zehnder Luna valves.

I drilled an exploratory hole to pinpoint exactly where the joist is, and it's 170mm from the face of the wall. There is enough space to just do a simple S bend using two 45 bends, keeping all ducts parallel and the same length up through the ceiling. I have decided to use multiple sheets of 18mm ply, with green glue and between each layer. The bottom layer will be use Fischer DuoXpand fixings into the blocks and some OB1. Just need to work out if I need 3no or 4no 18mm sheets to pad things out enough. I note that Zehnder specify a mass of 200kg/m2 for the wall, which suggests that 4 sheets is needed when combined with the awful 1970s blocks. Does this sound sensible?

Probably just paranoia about getting it right first time. My current Nuaire Drimaster 365 PIV is mounted on ceiling joists and the basic sponge isolators supplied with the unit did nothing to stop the hum. I ended up with a slab of 38mm worktop and aftermarket anti-vibration mounts to get it quiet enough in the room below. Partly I was concerned about the added height, but also I wanted to avoid as many additional bends as possible. However, I can see from the Zehnder ComfoPipe curves that the pressure loss is minimal at my normal background rate. The ducting and adapters arrived this morning, and it looks like it might just fit, the front pair of ducts clear the joist with a 45-45 "S" sweep. The rear ducts would require a short length of pipe between the two 45 degrees, and I need to check if they then hit the front ducts because they overlap when viewed from above. I probably need to model this in 3D space in CAD to know for sure. The will be a bit of wiggle room to play with because the cupboard is actually around 640mm wide wall-to-wall.

Thank you, sounds like I might be overthinking this. I should probably just build a basic frame offset from the wall for now, and pack behind with Rockwool, faced with plywood like yours.

I am fitting MVHR to a bungalow. Originally it was going into a kitchen wall cabinet (it's a Zehnder Comfoair 180) but duct runs are much nicer if I install it in the former airing cupboard. The airing cupboard is 600x600 and blockwork on all three sides. These walls back onto the bedrooms. Due to the location of a ceiling joist, the MVHR unit needs to sit forward from the back wall roughly 150mm. This allows the ducts to pass straight up without additional 45 degree turns. Given the proximity to bedrooms, and the 150mm of dead space behind the unit, I was wondering if it is worthwhile building some isolation in between the blockwork and unit? I was going to build a timber frame fixed directly to the back and side walls, filled with Rockwool RWA45, and faced with 18mm plywood. But that doesn't do anything to physically isolate the unit from the wall, only added mass, and does this risk making the frame become a mini stud wall that resonates more than the blockwork would? Is it worthwhile going through the effort of building a "floating" timber frame to mount the MVHR unit on, with spring/rubber mounts to keep it in place? Any advice or tips welcome.

Thank you, this is what I went with in the end. Looks fantastic in the slim profile aluminium frame.

I'm looking to replace all my windows. Most windows are a mix of either 2400x1200 or 1200x1200 squares. Currently they are mostly split with a vertical mullion into 2x 600x1200 or side casements with a large fixed central pane, but the design of the property looks so much better with the original simple square windows. I understand that 1200x1200 is right on the limit of a standard uPVC awning window when using 4-20-4 glazing, and exceeds it for 6-18-4. Anecdotally I've seen large uPVC awning windows fitted to properties and they felt so flimsy and were barely usable after a few years, whereas my smaller 600x1200 openers are fine after 30-odd years. I can't fit tilt and turn due to obstructions in the window reveals internally. I see that fully reversible systems like Rehau Total70R allow up to 1400x1400 sashes. They have a "flush casement" appearance when closed, and some systems have a brush pile to cover the hinge slot. I don't need any of the reversible features, although even on ground floor I suppose it could make cleaning easier since you're standing higher inside. Does anyone here have these windows? Any disadvantages to be aware of? I guess they require more care with squaring the frame and toe-and-heeling glass during installation.

I'm planning on fitting a fully glazed aluminium door in my porch to let more light in the hall. I want the door to be glazed full height but can't decide between a single large glass panel or two panes with a midrail separating them. Adding the midrail adds a significant cost to the price of the door, but I'm not sure if there are any real benefits. I don't need to fit a letterbox slot. The fully glazed I assume wins on thermal and acoustic performance, having just a single pane. I assume that the midrail would improve the integrity of the door, but given that it's aluminium, how much does that matter? There's also the argument that if the bottom pane gets broken, there's half as much glass to replace, but then would I be able to get the same glass to match the top pane anyway? The midrail seems to win on security too, because if you smashed the full pane, you could push it out and step through, whereas the midrail glazed door would require crawling through broken glass. Any thoughts welcome.

If you go for a higher-end trickle vent (e.g. humidity-sensitive) check that they can physically fit on the frames in terms of width/height. There used to be a product sold by Aereco (their "EMM" vent), that were quite slimline at only 27mm height. I fitted a few before putting in a PIV unit and they work well for opening and closing themselves based on humidity levels. Now, Aereco only sell the EMM2 which looks similar to those offered by Brookvent and is a much larger unit (the Brookvent HY is 45mm height!). I think out of the standard vents (like the Slotvent), they're all much the same as each other. The only consideration you might have is upward-deflection or downward facing for the interior part. Upward-deflection vents should be less prone to feeling drafts. They also do a better job of hiding the holes, in case you are incapable of drilling holes in a straight line like whoever did some for my home's previous owner.