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   BrianKrebs (briankrebs@infosec.exchange)'s status on Saturday, 18-Jul-2026 02:30:29 JST BrianKrebs

   Noticed the abysmal indoor air quality as measured this morning by gadget we bought after last year's wildfire smoke turned the sky a Blade Runner orange for several days. Visibility outside is next to nil right now from all the wildfire smoke. So I dug out the box fan filter contraption I built last year. It's bulky as all get-out, but it brought the air quality to excellent throughout the house in about an hour.

   Last year instructions for building these things were all over the Internet. But really, all you need is a big square cheapo plastic box fan that you duct tape down on top of a cube of large HVAC filters. Total cost (depending on the thickness of the filters you opt for) should be ~$30-60. We used huge 4-inch thick HVAC filters, so the cost was a little more for ours.

   https://www.youtube.com/watch?v=DXya56NIaVM

   • Embed this notice
     MacCruiskeen (maccruiskeen@social.linux.pizza)'s status on Saturday, 18-Jul-2026 06:13:47 JST MacCruiskeen

     • Infoseepage

     @Infoseepage @briankrebs Yeah, I wouldn't want something that big for say my home office. But poking around the hardware store website, I'm wondering if you could use a smaller box fan (they have a 9" one) and one of those cylinder-type filters that are made to go in one of the floor-standing purifiers. I've got a Bissel unit that works okay but it's upstairs in my wife's room now.

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     MacCruiskeen (maccruiskeen@social.linux.pizza)'s status on Saturday, 18-Jul-2026 06:30:39 JST MacCruiskeen

     in reply to

     • Infoseepage
     • Zimmie

     @bob_zim @Infoseepage @briankrebs In the summer, why not just put the fan in the window blowing out?

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     Zimmie (bob_zim@infosec.exchange)'s status on Saturday, 18-Jul-2026 06:30:40 JST Zimmie

     in reply to

     • MacCruiskeen
     • Infoseepage

     @maccruiskeen @Infoseepage @briankrebs You could make one to go in an upper corner of a room. Small wooden frame against the walls and ceiling with some door weather striping to seal it against the drywall, two filters, one box fan (or a grid of smaller fans).

     The reason for four filters is to get a lot of surface area. With only two, be sure to get the thicker filters with lots of pleating.

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     MacCruiskeen (maccruiskeen@social.linux.pizza)'s status on Saturday, 18-Jul-2026 06:46:41 JST MacCruiskeen

     • Infoseepage
     • Zimmie

     @Infoseepage @bob_zim @briankrebs Maybe I'll just buy another one of the Bissel ones then. Not worth a big hassle to save ten bucks.

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     MacCruiskeen (maccruiskeen@social.linux.pizza)'s status on Saturday, 18-Jul-2026 07:04:45 JST MacCruiskeen

     • Infoseepage
     • Zimmie

     @Infoseepage @bob_zim @briankrebs A box fan isn't very low noise. And the size is an issue. Also, there's the cost of the time and effort to make the thing. Not really feeling like it. And out house is not sealed up--right now all the doors and windows are open, because it would get like an oven if it's closed up.

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     Jim Jones (greatbigtable@mastodon.social)'s status on Saturday, 18-Jul-2026 09:38:51 JST Jim Jones

     • Infoseepage

     @Infoseepage @briankrebs I agree. We cut a circle that matches the diameter of the fan blades out of the cardboard box that the fan comes in and then place it on top of the fan and tape tape it down. This causes the fan to draw a lot more are through the filters.