Savage87

Do you have it setup in a different way?

There's a video about this one

I can't believe that so many users have the same problem, but yet we don't have a simple (builtin) solution... I'm currently looking at some MQ-x sensors..

Because of wind direction I'm a bit reluctant to do that. My exhaust is almost 3m away for the intake, to the right as you look at the roof. The wind usually blows from the west to east, this means from the intake towards the exhaust. I'm afraid I might get contaminated air back into the intake if I reverse them. ?

I wish I could move the intake somewere else, but my MVHR is in the loft it's not going to be easy. This has been designed in such a way that I keep bends and ducts to a minimum to reduce pressure in the system. I have attached a photo of my room and the offending chimney in yellow together with the wind direction. I'm going to do a bit more investigating in what sensor I need to pick so it can sense the smoke in low quantities. I haven't yet ruled out the carbon pre filter. I would like this to be a last resort. Thanks all for all your help so far.

looking good! ?

I have just turned on the MVHR a couple of days ago and I keep getting smoke into the intake of the MVHR from on of my neighbours chimneys which is about 10m away. With the weather not being so good in the last couple of days, they have been using their log burner and I'm kind of forced to switch the unit off unit I come up with the solution. My unit has a summer bypass and I was thinking of switching this on when I can smell/detect smoke. I'm trying to find a solution ESP based most likely to detect smoke in the intake and either switch the unit off or activate the bypass until no more smoke is detected. I'm in the process of building a Wemos D1 mini with Tasmota loaded on it with 3 relay to control the 3 speeds on the unit + other temperature sensors attached. I have some spare GPIOs so I can attach some kind of sensor and control the unit based on the smoke readings. If this fails I was thinking of making a prefilter box with some carbon granules and have the smell absorbed. But I think this way I will introduce more pressure into the system and I will have to speed up the unit and consume more power. I'm looking for ideas on how to proceed, any help is appreciated! PS: My neighbours are lovely, but this is a problem that I haven't foreseen and I need to find a solution quick so my wife stops complaining

Hi @Agnius, I was in the same situation as you are now a couple of months ago. I didn't know anything about MVHRs. This forum has a lot of useful information, a lot of resources and helpful people. I have just installed my MVHR, all DIY. I have done the design with the help of other people on the forum. All I need to now is to balance it. There's a lot to take in but you will get there. Good luck!

Thanks for the info! In my bathroom I currently have a sonoff basic (tasmotised) with a temp/humidity sensor which has an automation if the humidity level goes over 90% ie when having a shower, turn the bathroom fan on. I'm planning to do the same with the MVHR, I will be keeping the motion sensor for the wc (to please the wife) and I will possibly attach it to another sonoff basic which I can automate to work only during the day. Like you, I like to overcomplicate stuff, but I need to keep things simple for the family

@MJNewton How did you connect the shelly to the aico relay base? I saw that you have boost switches for the bathroom/ensuite and you also have a humidity sensor on the extract. Do you have an automations based on humidity or do you use the swithes. I'm currently doing the wiring for my unit, which has an integrated humidity sensor, I also have a humidity sensor in the bathroom, but I'm not sure if to use a boost switch in the wc or have in on a motion sensor?

My house is 90sqm and I paid 1350 pounds for the everything including the unit which was 550 pounds, a Nuaire MRXBOXAB-ECO2.

great stuff @MJNewton How did you get the temperature sensors inside the ducts? Are you not worried that might create leaks in the system?

And this is how I insulated the 5inch ducts.

This is what I've done in my loft, It's still work in progress..

I had a similar situation with the PIR sensor for my stair lights. I have ordered another sensor so I can replace it and the new one was came from Germany and it was faulty. It took me about 1 hour to figure out that the new one not working. The old one had just a a loose wire with I had so solder back on and 5 minutes later everything was back to normal. Wife is happy

I'm having a radial sysyem done and the unit will be in the loft. I'm planning to insulate the radial ducts from the manifold about 1m up to where it goes under the insulation. I have been told that all the ducts in a cold loft need to be insulated. I had a word with someone at bpc and he was saying just to insulate the 125mm pipes.

I wouldn't worry to much about it unless they ask you about it, my local BC said just go ahead and fit the unit..

Does anyone have any left over radial duct? I'm looking for any length of Airflow Airflex PRO 75mm red duct 9041130

I don't like the idea of having the control panel, it's just only option that I have to make the unit smarter, I would have loved an app but the manufacturer doesn't have a bridge or app. I'm planning to hack the unit anyway with some home automations and relays via a microcontroller ? . I just want to be able to control temperature for the summer bypass and I also want to see the temperature from the supply end extract ducts. The unit has a built in humidistat but I'm not going to rely on it, I have a DHT22 in my bathroom and that triggers my extract fan at the moment.

As a quick update, I have settled for a Nuaire MRXBOXAB-ECO2 unit which is more or less identical with the Domus HRXE unit that I was looking to buy initially. I'm going for Airflow Airflex PRO 75mm radial ducting. BPC says that this is the best duct to use in a radial system because it's more flexible that other brands and it's anti static and anti bacterial lined. Good idea or just another sales technique? I would like to know how many of you have visual controls for your units? I would like to buy the https://xpress.nuaire.co.uk/mrxbox-vsc-wall-mounted-lcd-touch-screen-controller/ just so I can see what's going on with the unit and have the extra features that come along with it. It's over 200 pounds and don't know if it's worth it. I wouldn't want to buy it and then realise that I could have live without it.

@ProDave How did you get hold of BH anemometer? The spreadsheet that you have attached, does it have actual measured values in it? I had a word with my local Building Control and they said they are not interested in any air flow values, they said, just go ahead and install it..

reading in the quiet vent brochure, it says: "It is recommended to install a flexible or solid acoustic silencer between the ventilation unit and the air distribution box in order to further silence the sound of the fan." and I've also seen other manufacturers say to fit them on the ducts that go to atmosphere. So, I'm a bit confused on what the best practive would be.

that's what I'm planning to do, did you get the flexible or semi flexible silencer? Which duct(s) did you connect you're one(s) to ?

What is the best location for the silencers? Is it before the MVHR unit or in between the unit and manifold/distribution box?

as @Oz07 said, thanks @PeterW I'm clear on the elevation. I'm not clear on south/north positioning and intake/outlet position based on my geographical location.