Haven21h ago

#AskFedi #IAQ #CleanIndoorAir #HVAC folks:
My apartment's HVAC system, which is connected to an individual rooftop unit with its own fresh air intake ducts--is currently down. My understanding is that the issue is with the control module that is connected all the in-apartment on this floor, so all of our units are turned off.
I have a CR box air purifier, and a small portable one with miniature #HEPA filters, and an #Aranet4 air quality monitor.

Maintenance have installed a one-hose portable AC unit, with thermal tape around the edges of the open window. From the perspective of minimizing aerosol concentration, what is the best approach with respect to fan speed/mode options, i.e., always on, or only when cooling; blocking the undercut in the door, and opening a window in a different room?

I had also considered not using the portable AC at all; minimizing opening of the door and venting via windows with colder air at night.

Show threadNilaJones16h ago

@haven

It depends on what's outside your windows

Like, do you ever smell cigarette smoke through your windows? Are there people walking right by the windows? Is your window next to your neighbor's window which is open?

Outside air is not magic. But if the air coming in your window hasn't been exhaled by somebody else, then that's great!

What I would do, in that case:

Open the most isolated window when you're running the AC. Or if they are all the same, open the one farthest from the AC

Run the AC for minimal time, and turn off the fan when you're not running the AC

If you can get away with just opening the windows at night and closing them in the day, and not using the AC, that's great too. Saves a lot of electricity

If the air coming in through your window is not that clean, and if you have the energy for it, you can rig up your CR box in the window (or make a new one to fit), to filter incoming air

This is what I do, because my window is right next to a walkway. People are constantly smoking and coughing up a lung out there

Show threadHaven
@NilaJones Thank you. The portable AC is thermal-taped to a window that opens to a courtyard with another building on the opposite side, but no other units are super close. The outage is only on my floor on my side, so I expect few other people have their windows open. The only other window I can open is on the opposite side of the apartment in a different room, so flow between them obviously isn't ideal.
4:33amWeb
Show threadNilaJones16h ago

@haven

Actually, opposite side of the apartment in a different room sounds pretty ideal to me, if you can keep the doors in between open

I am glad to hear that your windows are not exposed to other people! Maybe it will work just to have them open at night