Deniance

That’s what I did as a temporary measure and I managed to get air to blow out of the pipe!

Righteo,I’ll crunch the numbers after work , thanks

How do I calculate pressure drop?, I’ve found all the values in the Nuaire catalogue for each bend and length of ducting, do I add the entire branch system together or do you calculate each run and use the longest run ive drawn the entire branch system out and added the values of each item onto the drawing, and if I simply total them all up together I get 159 pa for the supply branch, 122 pa for the longest run, may need to draw it properly to get exact figures

There is 1 metre of attenuator in each duct before the terminals of each room, it’s the Nuaire attenuator that slides inside 1 metre of duct, heavy black rubber thing, looks like it takes up most of the area inside the duct, but I guess that’s what it’s designed to do?

so I’ll make a list of all the bends and lengths of duct , go to Nuaire site and right down the pressure loss for each one then add it all up? What do I compare that with?

Hi everyone I need some mvhr help please… ok so about 10 years ago I looked into MVHR and got all excited and I bought a Brookvent air cycle 1.1 , the green one, I did a bit of research and armed myself with the thermal ducting from Nuaire and all the various bits and bobs, I got as far as installing all the ducts in the loft , then I read that mvhr was pointless as the house is 150 years old and will never be airtight and all that jazz, so my project kinda got mothballed and everything went in the loft and just left! well, fast forward 10 years and I had a small flat roof bathroom extension built, and I needed an extractor fan, so I started thinking about the mvhr unit I have in the loft and whether it is worth trying for MVHR again? We had new windows fitted and our condensation levels are getting out of hand, my partner also bought a co2 monitor with an alarm that beeps, and in the middle of the night it starts beeping, not every night but some nights it alarms and on the sticker it says it’s at medium danger for c02 levels. So temporary connected the mvhr unit with some flexi, switched it on and connected it to the old ducts in the loft and got some air blowing to the bedroom, it’s been 2 weeks now and the c02 alarm hasn’t gone off at all and condensation has been reduced by about 50% so it may be worth installing it properly just to get some ventilation running in the house. So everything I read 10 years ago I’ve forgotten so where do I start redesigning the mvhr? do I need to start with house total volume to see if the unit is even big enough? it’s only a 3 bed terraced house im extracting from the bathroom and utility /kitchen which is about 1metre each away from the unit, so just two extracts, the vent to outside is straight out the wall so it’s only 300 mm from the unit, the fresh intake is only about 1.5metres away, and it’s supplying 4 rooms with fresh air, (3 bedrooms and a living room) the ducting that’s already installed is 125mm holes on the unit that will go to 125mm round adapter that changes it to 220x90mm Nuaire ductmaster all the way through in a branch system, and I think at the end of each branch in the loft it goes back into a 125mm round adapter for connection to the rooms the duct runs are probably 4m to bedroom1, 9m to bedroom 2, 13m to bedroom 3 and then if I drop from the loft to the living room ceiling it’s probably 18m? (The 18m run takes 4 90 degree bends to get there) sorry for the long boring post I guess I just need to know the first step, which I guess is measuring all my rooms and corridors and getting a house volume and then comparing that to the unit specs? Anything else I need to measure or look for? if you’ve got this far thanks for your time!

Hi all, hope your all well! Just a quick hello! Just arrived here and hoping I can get some help! I’ve had a read so far and it seems like I’m in the right place!