Low-tech air filter for bad air quality emergencies

By: +David Herron; Date: November 16, 2018

Tags: Air Quality » Air Filters » Climate Change

This solution came thanks to a friend who suggested, via Facebook, that a 20x20 inch box fan plus an AC Filter would work to clean the air.

Just how bad is the air at the moment?

As I noted in an earlier posting today, I have a portable air quality monitor widget. This shows just how bad the air is, and today the readings are the worst I've seen since this fire situation began. Most of the year the reading for PM2.5 is in the teens, but today it is squarely in the region of unhealthy air. And, the local air quality officials predict air quality over the next few days will keep worsening. As I write this the Camp Fire is only 30-40% contained, FWIW.

That means over the next few days health dictates taking some kind of action. I considered driving south and staying in a hotel room, but for how long? And, I cannot afford to take such a trip. Staying indoors means having air that is less unhealthy than the outside air, but who wants to stay cooped up all the time?

There are filter units meant to clean the air, and are vital for those with sensitivity to dust or mold or other environmental contaminants. I haven't looked at the price of such filter units, but am expecting them to cost hundreds of dollars and that I only need the thing for a few days.

When going out of the house, a face mask is recommended. I happen to have some face masks around, and do not have any recommendations of the best face mask to handle extreme air pollution like this.

At home a less expensive easy to implement air filter system is exactly what my friend recommended -- a fan, with an AC Filter strapped to the front.

After a trip to Home Depot, I came up with the implementation pictured above. I don't have a 20x20 box fan, so I got a smaller filter that fits on the fan that I do have. Namely a 14x20 filter, as you can see in the picture. Using a few bungee cords to hold it in place, and you've got a nice simple solution.

There are many kinds of AC Filters with different levels of filtration.

What I got is a Filter where the labeling claimed the highest level of filtration. Cost - about $20. I'll leave this running 24/7 until the smoke clears from the fires.