Giko

Thank you for advice, but if I understand correctly, then 1 duct would only be enough for normal Unit operation, but let's say if I have guests over, and now there are 6 people inside, so according to guidelines I will need to increase it to 180m3/h, and that may get loud with single, or even two ducts. Basically, I want to get it setup, so whole MVHR system works quietly even on max load. My second concern is, if I put supply in wardrobe, then some unpleasant smells may travel to living area (e.g. it's normal to keep seasonal shoes in there, that may be stinky). It seems it's very popular to rely on airflow through whole house (e.g. bedroom in, bathroom out), but I wonder how closed doors may affect airflow pressure? E.g. you sleep in bedroom with closed doors generating a lot of CO2, at the same time there's ~40m3/h air supply above your head, so can't it happen that new air will mix up with CO2, just because it can't leave the room fast enough due increased pressure? Perhaps it's more efficient to have supply and exhaust in the same room (at opposite ends)? The wall, where exhaust duct is leaving, is not an external one, there are other apartments/shared hall behind it. Though, I have no idea where duct goes after that (I guess to the roof).

Hey all, I recently bought an 45m2 apartment with unfinished interior, it came with 191m3/h MVHR unit with only external ducts (125mm) installed, internal ones are up to me. So after reading a lot about it (this forum was a bliss!), I made a design with calculations: I chose to have 2 double inlets in living room and bedroom, as well 2 double outlets in kitchen and bathroom, and 1 singular outlet in wardrobe, all this with 90mm flex (semi rigid?) 90 mm vents. Now if my calculations are correct, it may not be enough to run unit at 100% load without any noise, as air velocity through vents would peak at ±3m/s (as I am aware it should be no more than 2.5m/s). Now on the other hand, I am unlikely to use unit on the max very often (perhaps only when I have guests over). So I am thinking to add 1 additional outlet in hall (next to exterior door), and 1 more in living room (close to bedroom door), would that make sense? Or perhaps I am just overthinking? Never had seen MVHR working live, and wouldn't want to regret it later, If I didn't add additional vents when I had opportunity. Attaching calculations and design, I would also appreciate tips on how to improve it. Thank you. Also a note, that I am not from UK, thus regulations in my country are a bit different - actually, there are no strict regulations here for residential places, only recommendations.