sun as seen through carr fire smoke

Morning Sun as see through the smoke of the Carr Fire

Welcome to the mountains and fresh air of the upper part of Northern California!. Well, normally… If you’ve been in the Shasta county area since the Carr Fire started you know the air is anything but clean and fresh. Besides just impeding our view of Mnt Shasta and the surrounding beauty of Northern California this smoke can present a significant health risk.

One solution that is often presented to help with his problem while driving is to set your air conditioner on recirculate. This does help, instead of continually pulling in contaminated outside air you recirculate the air that is already in the cabin. However unless you got in your car in an area where the air is clean you still have that same contamination in your car.

There is a solution, but before I get into that lets consider why this is even a problem.

Contamination from the Carr fire

While you might think that breathing the smoke from this fire is no worse than breathing smoke from a campfire that is not really true. True some of that smoke is from the burning forest, but in addition over 1000 homes and other structures were also consumed by the fire. Some of these homes were older. Many toxic materials are now floating around as ash. These materials may include asbestos fibers, ash from lead paint, plastics, as well as pesticides and other products that are commonly found around the house.

How bad is it? The local air particulate monitoring location on Breslauer Way has measure a high enough particulate count for much of this morning (Aug 7 2018) to be Very unhealthy. That is one step below hazardous levels. Calfire and other official agencies have stated that for health reasons people should consider wearing N95 or higher rated masks while outdoors.

Automotive Cabin Air Filters

Most vehicles now use cabin air filters. These are relatively inexpensive and easy to change. In fact they should be changed every 12 months or so depending on driving conditions. Standard cabin air filters are meant to trap larger dust particles and pollen. However they are not very effective for filtering smoke and other fine contaminants that are currently found in our air. For this you need a filter with a higher efficiency rating.

If we were talking about home or commercial AC air filters we would see ratings like MERV, MPR and FPR. For these applications you would choose a carbon filter with a rating of MERV 11, MPR 1200 or FPR 7 or higher. ( More information ) Unfortunately automotive cabin filters usually don’t come with one of these standard efficiency ratinga for comparison.

There are things to look for however when choosing a cabin air filter for your car. The many of the better filters use activated carbon others are labeled as HEPA filters. Normal cabin filters have a performance of as low as 40-60% and can only trap particles larger than 5 µm. Hepa filters are tested to have a performance of 99.95% or higher and trap particles as small as 0.3 µm. Bottom line, HEPA rated filters are far more capable of trapping smoke and other airborne contaminants.

While changing your cabin air filter to a high efficiency filter is not as effective as wearing a N95 mask it should help considerably for longer trips as long as you have your car AC in recirculate mode. The price is also not that much different than a standard cabin air filter. Hepa and carbon filters can be purchased online for as low as $8.00 to $20.00 depending on the model of your vehicle and are well worth the extra piece of mind.