Hi /diy/, I am trying to come up with the best way to fix a room with poor ventilation. It has a single sliding window, right next to the entrance door so airflow to the opposite corner is non-existent, that's where my bed and desk are. Weather is fresh right now but often times the room feels damp, during summer heat it gets very hot inside with stale air even though I can feel air is fresh right through the window, but there is no way to make it circulate through the room. I've made a simple drawing to show the bedroom dimensions in centimeters. I've also drawn below that what I have in mind, I will make clear I have zero knowledge about ventilation in general. What I'm thinking of is adding simple ducting (circular, cheap semi flexible aluminium duct) that starts roughly at the wall opposite from the window, running through either side of the room and ends on the top part of the existing window. The bottom side of the window would be covered with plywood or whatever to simulate two really small windows serving as intake and exhaust, these would be around 10cm x side, or 4 inches, separated by around 100cm (hopefully enough to prevent "mixing"). The end of the duct on top and the bottom square to serve as "intake" would have gaps around them because a hermetic seal on a window that must remain functional for rain is hard. At first I thought running the duct through the right side of the room (yellow line) for aesthetic reasons, because there wouldn't be a big duct hanging on the entrance, but the problems with that is firstly, there's a wooden bookshelf right on the other side of the window that I'd need to drill a big hole to pass the duct through, then there's my blinds headrail (little orange line next to the window), this doesn't leave a lot of space to work with, at much 3-4 inches without needing extra work to move it frontwards, also would need a few sharp 90 bends that I'm just now learning adds a lot of air resistance.
So I reconsidered doing it on the left side even if it looks a bit ugly, only 4 45 degree bends.Next thing to decide is duct sizing, I have no idea how much airflow is actually needed for what I want but google recommended 4-6 "Air Changes per Hour", did the math and got 70.6cfm. Then I looked up what cfm's can the smallest ducts handle and according to that I'd need at least 6". Fans come next, again I don't know how much power I actually need, prices are all over the place and I'd of course rather go for something cheap, most of the fans I can find seem to be axial fans or wall mounted, and "inline" or duct fans. I feel like inline would be perfect for my aplication, but most I've found seem a bit overpowered (>170cfm) for my needs, but again I don't know how much I really need. Lastly there's fan and duct end positioning, I feel like it'd be best if one end of the duct was at the opposite end of the window, but I don't want it above my bed either.Thoughts, opinions or advice? Has anyone tried this and what were the results like? Would I really need a large diameter duct that'd look ugly, considering the short distance (5~ meters)?Does placement and direction make a big difference? For example if I were to put the fan next to the window, drawing air through the other end of the duct, or pushing in, does it really matter?Apologies for ESLness :)
>>2975280You have such a small room, why do you need forced ventilation? Just leave the window open longer. Even if it feels like air isn't moving much, there is definitely some exchange going.If your air changes in the room are low, start by checking if your window is vented or not. Modern PVC windows typically intentionally have small vents, usually along the bottom. If it does not have vents, consider making some, look up how to add air vents to PVC windows. It's mostly just about preventing rain from falling in with hole placement/covers. Beyond that, if the whole house has a problem with ventilation, add a central positive pressure venting fan. If you have roof space, you should go through there to reduce noise leak from outdoors. If only your room has this problem, then you can go with a smaller fan, again, ideally through the roof. You do not need high CFM or high ACH if its a very quiet fan that can run a lot, so I'd recommend buying a large but well pressurizing computer fan if it's just your room. If it's whole-house, then you do need a higher power unit. There's also the very cheap and very easy solution of putting a regular fan in front of the open window, ideally facing outside.
Think of the decibles.
>>2975280It seems you're overengineering a solution. Just buy an inverter AC that has a dehumidifier mode and get some contractors to demo where you want them to put it so they can make a hole connecting the AC to the compressor. You have to demo way less compared to HVAC which has you taking down big chunks of wall to put ducts. Get someone to install anything air related because DIYing that shit is more expensive and retarded than just using contractors. Or you can go the even more poorfag route and install a swap cooler right on your window by cutting the window and putting the ventilator part towards your room and sealing it around the seams.
