I’ve been racking my brain lately thinking of what are good methods to increase internal airflow in a house with few windows, all facing the wrong direction to catch wind. What are your ideas?
Edit: Breaking a wall to make more windows isn’t an option.
Suck the air out. Pushing air in with fans creates a higher pressure zone in the house. You won’t move as much air. On the upper floors where it’s warmer suck the air out of what windows you have, but push the air in at the lower windows. Personally my house doesn’t have any windows, this is Lemmy we use Linux here.
Peak lemmy here.
I have been trying to slip in Linux references when I can. I swear 25% of our user base is Linux SysAdmins.
I swear 25% of our user base is Linux SysAdmins.
That’s impossible, as it would mean 25% of our user base is also furry. Wait a second…
where it’s warmer suck the air out of what windows you have, but push the air in at the lower windows
computer case airflow!
I suppose that is an accurate comparison.
Fuck! Exactly the idea that hatched in my head.
So lower front fans are more efficient to suck in cold air than higher ones, while the exhaust fan in the back is higher and more efficient for moving hot air away from the case as hot air rises (ryzens).
But doesn’t it better to keep your house at positive pressure to keep the dust out?
In theory, but by lowering the effectiveness of the fan. You could put outward facing fans in each window and a furnace dust filter on the window sucking the air inward.
Example blowing air into a balloon. The air goes into the balloon, because the balloon can expand. If you had a balloon as a house, and the fan was your mouth, your house shouldn’t expand. The air has nowhere to go, so it doesn’t blow in very effectively.
I personally kept most of my house cool by running a single window AC that has a filter and a single fan. The AC blows in at the lower levels of the shaded side of the house. The fan sucks out the hot air from the second floor One ~8,000btu AC will keep the house comfortable until it hits ~97f.
Moving air out of a house is more about sucking the air out than pushing the air in. As long as their is a flow to it.
this is only effective if the inlet is well filtered, otherwise you will just be blowing outside dust in anyway
My house has so many windows. I’m such a nub.
Mathias Wandel on YouTube made some good videos a few years ago about maximizing airflow through a house with fans. One big finding was that rather than having a fan directly in a window or door pointing out it is actually best to have it a few meters away and directed at the opening. That allows the fan’s airstream pull in and start moving much more air in the room out the opening. He used strips of paper hanging in doorways around the house and also I think took anemometer readings to get good measures of the airflow.
I think the general theory is to run the fans starting in the evening once the air temp outside is lower than inside, then close up the house in the morning to trap the cool overnight air?
https://youtu.be/1L2ef1CP-yw?si=aLTlAMKv_3p3ri2q I think he may have made multiple videos on the topic
Yeah that was really fascinating
You’ll see this sort of thing in action when firefighters are ventilating a house with fans. They’ll move the fans back until the air stream covers the entire opening it’s aimed at. Any less and the spots the air stream doesn’t hit are gonna have air flowing the wrong way.
A good trick I’ve found is that fans in long hallways are markedly more effective than pretty much anywhere else.
I do this all the time, just stick 2 fans in windows on opposite sides of the house, 1 facing in, 1 facing out. Bam; cross ventilation!
Bonus tip: set them a couple feet away from the window frame so that you create a venturi effect and move a ton more air.
I would have thought putting the fans tight in the window would move the most air. Can you tell me more about this Venturi magic?
I stole this from someone in a different comment: https://youtu.be/1L2ef1CP-yw?si=aLTlAMKv_3p3ri2q
It doesn’t answer your question, but it demonstrates his answer.
Here is an alternative Piped link(s):
https://piped.video/1L2ef1CP-yw?si=aLTlAMKv_3p3ri2q
Piped is a privacy-respecting open-source alternative frontend to YouTube.
I’m open-source; check me out at GitHub.
If you put the fan right in the window, it’ll suck the air right back inside around the fan. If you put it farther away the air stream has distance to widen and pull in more air. That way you can get the air stream to “cover” the whole window, Not allowing any to flow back in through that window.
I have square fans that I sit directly on the window cill.
You’ll probably still get more air moved if they’re sitting back on a stool or table, unfortunately
Meh, it’s good enough without being inconvenient.
In college I lived in an old house with bad windows without AC. So to keep the house cool we had all windows open with fans blowing air facing outside. You can also do half the house outside and half blowing inside to get a fake cross breathe
Attic fan. It is a game changer.
Attics aren’t a thing around here, unfortunately. I could get a warehouse-styled convection fan, but the cost is a bit spooky when I don’t even know if it’ll work.
Research and shop around for a type of fan called a centrifugal blower or utility blower. These fans are designed specifically for entire space ventilation. They sound like tiny jet engines. The same fans that inflate bouncy fun houses or the fans you sometimes see on a storefront wet floor during a rainy day to blow dry. Output rates of small units 100 to 500cfm (cubic feet per minute) will replace all air inside a 2-car garage space every hour. Mid range blowers 600-900cfm will replace that same air space every 5-10min (approx. 6x per hour). Higher velocity blowers >1000cfm will clear an entire 1-story house (typically for HVAC or factory use) and is more efficient and quieter than the biggest attic fan style unit.
After you have bought the raw power of air movement, then experiment with positive pressure and negative pressure flow setups (suck vs. blow). And then finally other per room or per window configurations as needed.
Thanks for the tip, it does seem quite interesting. From what I could find locally, prices are all over the place, so I’ll spend some time reading spec sheets haha
I have a similar thing with how my house was built. What I do is open all the windows that will open and setup small box fans in the windows on one side of the house to push the inside air outside. Seems to work fairly well.
I used this style of fan to get the neighbors cigarette smell (that seeped in through the goddamn walls) out of my downstairs. I had a two story apt, with windows like this, where W=window room and R=room without a window;
W|W R|W
The best airflow was for the top floor where the windows were opposite and the natural breeze could do its own thing, but the single downstairs window was good enough to clear out the cigarette smell on its own so long as an upstairs window was at least open.
You say your windows are all on one badly ventilated side; have a push/pull setup with the airflow. Use one of your current fans to bridge the gap at the stairs and it’ll work great.
I found i got the most airflow when pulling in downstairs and pushing out upstairs, regardless of temperature, but i live in a hot area. Definitely test yours to see what works best in your situation.
I never tried using fans away from the windows as mentioned before me, but that’s definitely worth doing as soon as you can, just to see how much it inproves your situation.
Are all the windows on one side? Are any of these full door length? Front and back door? You’re not giving us much to go on.
Get a full roll out screen door for the front and back doors. You can also take a big fan, place it just outside the door pointed into into house.
Assuming the windows are parallel to the wind, can you construct a vertical awning (if I can call it that) to catch the wind?
It’s an European style long, tall and thin house with wonky internal geometry. All windows face the street, parallel to the wind, at different heights. That’s what gives me the most trouble - getting any air flow to effectively make a C curve.
can you construct a vertical awning (if I can call it that) to catch the wind?
I thought about it, but it seems like it’d only make things worse by creating an even bigger region with stagnant air in front of the windows, unless I were to invade the street (which is highly illegal, for obvious reasons).
There is literally zero space between the front and the street?
Do you own the house? Is so you can look changing out windows with this vertical swing style to catch the wind. https://homeimprovementsupply.com/images/product/medium/2815.jpg Orientate to catch the wind (but remember you need the air in the house to have a way to flow out too).
There is literally zero space between the front and the street?
The opposite - there’s too much space, with buildings on both sides. Think a room as tall as the house in front of it, but with the street-facing wall removed.
So your neighbour’s houses are sticking out further? Well you’re probably going to have to rely on fans then. And the rolling screen door. Place one fan outside the door pointed into the house. On the other side place it inside the house and pointed out.
Do you have a forced air furnace? Some of them have a switch to turn the fan on, which would pull in air and push it out the vents (just without the heating).
Get a portable fan and place them near the windows?
I’ve tried various configurations of fans pushing and pulling air, but none are much help. The internal geometry of this house is wonky.
Maybe sharing a plan of the house would help(if it doesn’t affect privacy or any other concern)?
Oscillating fans help.
They’re good for circulating air that has already entered a space, but not so good at getting the air there to begin with.
True. But I tried the fan-in-the-window technique and I think that if your window is so large that there’s a huge gap, it’s not terribly effective.
I did have good luck one year putting a popcorn bowl of ice water in front of a fan pointed right at me on my desk. It doesn’t cool the room, but it cooled me.
I open my windows and set the HVAC to “fan mode.” Many of the ducts are right below the windows so it really helps get the air moving. It doesn’t create a “wind tunnel” but it does help move the air around everywhere.
I feel like if you have airflow problems, you probably don’t have forced air ventilation.
I usually can get some if I have one window opened high and one low. The pressure differential is not a lot but it will cause a flow.
