How to survive bad air and heat from summer wildfires

I’ve started a couple of threads on related topics in the last year, but I thought I’d bring it all together in a larger discussion. I live in Northern California where our primary disaster scenario has been with wildfires, which are getting quite extreme now. For the past several years every summer and/or fall large areas of the state have had to deal with terrible air when we are told to keep our windows and doors closed and avoid going outside if possible. Usually, during this time it’s also hot and sometime, in some neighborhoods, our power company turns off the electricity to prevent further fires from igniting because of downed power lines.

I’ve haven’t had my electricity turned off yet, but I still dread these days or weeks of lockdown with closed windows and heat. I don’t tolerate heat well and I always have to have a draft. Last summer I just couldn’t stand it and started opening doors and windows anyway, even though the air was in the red zone. Now I’m trying to prepare for next summer. Wondering what folks in similar circumstances are doing to prep. Here’s what I’ve done.

– I’ve gotten three air purifiers for my house. I have to admit sometimes I run them when the window or door is open, which is counterproductive, but better than nothing, I guess.

-I have two OPOLAR little fans I bought on Amazon. I love these fans. They are handheld and very versatile. About $13 each. They’re good for travel and all sorts of other activities and they don’t draw a lot of power. I don’t know if they’ll really be enough to keep me cool though in a heatwave scenario with closed windows, especially.

-I bought a MERV 13 filter, which I plan to put in one of my windows and combine with a fan, to suck in filtered air even when the air is bad. It’s a little bit of a DIY project because I need to figure out how to cover the rest of the open window with cardboard and tape so unfiltered air doesn’t leak. The amount of air that enters that way is very low though. Probably enough to replace the oxygen but not enough to feel a breeze. I also don’t know if I should have another window where the air is being pumped out to keep it circulating.


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  • Comments (11)

    • 9

      I’m sorry that you have to go through that every year. Good air is something many of us don’t appreciate until something like a fire affects that. 

      While I don’t have this issue where I live and don’t prep for it myself, I think everything you listed above is smart and a good decision. 

      If suddenly I had bad air in my area, I think I would go out and get the best quality furnace air filter at my local hardware store. I then would use that, cardboard, and duct tape to make a DIY window air filter. 

      For the heat issue, maybe get a small window AC unit. Use that in combination with your DIY window air filter so dirty air isn’t coming in through that way. Fans are awesome so that is good that you have a couple of those. Putting your feet in a bucket of cool water can be really helpful as well.

      Shutting your blinds during the day will keep a lot of the heat out.

    • 5


      I’m still looking; there have been some basic solutions.

      Not involving me (I have a different list of disabilities) but some of the guys at my local DAV chapter did address this air quality issue and they were successful. The DAV bldg is closed during quarantine.

      Just wrote up a yellow stick-on with thread title so, if/when I run across material on this subject, will post it.

      • 6

        Lay in a  good supply of N95 or N100 masks

    • 6

      My 80 year old grandmother lives in California and does not have a central air conditioning system and struggles with heat every year. She has her TV watchin chair next to a window with a small window AC unit. They range from $250-$1000. I think you should be fine with the smallest and cheapest unit if you sit right next to the unit during the day and maybe have some additional rotating fans to circulate the cool air around.

      A passive way to get fresh air in your house is to have something like a window air filter like this. Place a giant box fan infront of the window and that will pull in some good fresh air from outside. The box fans push a lot of air and are only about $20-$30.

      Besides that, I think you are doing great and are doing just about everything you can. 

      • 5

        Thanks, Conrad. That air filter isn’t rated, though. It’s not clear what it actually filters out.

      • 6

        You are right! While it does say it filters out pollen, odors, and gases, it doesn’t say how well it does or have a filter rating. Good catch!

        I do like the design though.

    • 9

      Re: “I also don’t know if I should have another window where the air is being pumped out to keep it circulating.”

      This is a really good question. My opinion here is that you should specifically not have a 2nd window open. Airflow into the room is predicted by the fan that sucks air through the filter. No matter what, an equivalent amount of air has to leave the room (otherwise the room would explode). In your case, the air will escape through leakage via random cracks in the building. This is good because the room is being pressurized by the fan, and the positive pressure will buffer against bad stuff leaking into the room through those same cracks. In building science, we call this positive pressure ventilation, and it’s widely used for the general purpose of keeping contaminants out of buildings, although more commonly for things like radon.

      • 3

        Super smart principle! I forgot about this.

    • 8

      On the subject of setting up air filtering with a MERV 13 filter and fan. It requires a small DIY project and DIY is not my forte. I could use some advice.

      The MERV filter fits in my double hung window, but leaves a lot of the window opening unobstructed, so I have to find a way to cover it so that bad air doesn’t get in. I was thinking of cutting out a large piece of cardboard so that it fits snugly in the window opening then attaching it with duct tape, but on second thought that seems like it could rip up my paint. Plus, I would only want to cover the window this way on days when the air is bad.

      Alternately, I was thinking of gluing some kind of foam pieces on the edges of the cardboard, but I don’t know how I would attach the foam securely to the edge of a cardboard piece and I don’t know how well it would block unwanted air.

      A third option would be to use something like saran wrap and tape to block off the open section of the window, although again I’m not sure how I would attach tape in a way that didn’t mess up my paint.

      • 5

        I would use Gaffers Tape instead of duct tape. We use gaffers tape to label different boxes in our house and it doesn’t leave any sticky residue. 

        Gaffers tape is used in the film, photography, and theatre field because they stick things to various surfaces without it leaving a sticky residue or damaging the surface. It is made of cotton instead of the normal vinyl of duct tape so it resists heat better than duct tape as well, which will be good for a hot window setting.

    • 4

      Yet another reason to have a good air filter during wildfire season.