Preparing For The Worst Fire Season Ever

I have severe asthma. As such, fire season in California poses a real threat even without the additional risk of a respiratory pandemic. Many of the comorbidity factors from covid-19 are related to decreased breathing capacity. If you get pneumonia while also having an asthma attack, you’re gonna have a bad time. As such, I wanted to make sure to prepare early since all the N95 masks are already taken for coronavirus.

N95 masks are the ones that can filter smoke. Incidentally, they can also filter coronavirus. Therefore they are in extremely high demand by medical professionals who need them. I would not buy them for that reason. Also, I still have a dozen or so left over from burning man last year. (N95 also filters playa dust.) Sadly though I tried, I was not able to donate these because the box was opened.

I have spent several years together with friends exploring the best ways to filter the indoor air quality during fire season. According to NASA research, one of the best things you can do is to have the right kind of indoor plants. Unfortunately while this filters many harmful chemicals, in my experience it does not seem to be effective against smoke. Additionally, it’s slow. I have tried many different kinds of air filters, and landed on a very solid and excellent setup.


($10 ea) 20×20″ MERV 13 Filter

($20) 20″ Box Fan

$30 Total

Houses and Faces

An N95 mask is certified on a scale called NIOSH. N95 mask certification actually has nothing to do with viruses. It is a scale for filtering particulates which do not contain oil. Incidentally, that includes viruses as well as smoke. N95 masks are also certified for biocompatibility since they are touching the face. There are many other factors that go into the N95 mask certification.

NIOSH Ratings

For the purposes of this post, all that really matters is filtering smoke. So when we look for a house filter to fit the need, we don’t necessarily care if it’s ok to wear it on your face or how resistant it is to oils.

House filters are rated on a completely different scale called MERV. MERV 11 and up are rated for smoke. MERV 13 and up are also rated for viruses and bacteria as well. An average MERV 13 filter currently costs under $10.

MERV Ratings

There are any number of expensive air filter products you can buy which run up into the hundreds of dollars. I am going to show you how to accomplish the same quality air filtration for just $30.

One common size for MERV 13 filters is 20″ x 20″. This is the same size as the generic $20 box fans you can find at any department store from Walmart to Home Depot.

It’s a simple matter of using a few pieces of duct tape to attach the filter to the fan, and you have one of the highest quality air filters you can get for just $30.


For just $30, you have essentially the highest quality air filter possible which will last for years depending on your situation. In my case, one or two MERV 13 filters lasts me the full fire season.

Breathe easy!