Resources and Support for Multiple Chemical Sensitivities, Environmental Illness, and Chemical Injuries in Canada

VOC Filtration

The MCS adage of “eliminate, separate, ventilate” holds true. It is always best to eliminate the source of VOCs entirely if that is possible. If not, then sealing or separating the offending item is the next best choice. Ventilating, if the air brought in from outdoors is clean enough, can help to reduce the amount of VOCs in the living space while filtering can help to “polish” the air by entrapping the offending VOCs.

Below are instructions on how to easily and relatively inexpensively adapt a normal household fan into a filtration device to filter VOCs. I use the fan for extra air cleaning when necessary. I also use it when I need to work on something toxic for me such as when replacing computer parts. Directing the fan away from my work area draws the fumes away from me and they are entrapped by the fan.

CAUTION: Always be sure to check the fan does not overheat. Please have someone knowledgeable (if you are not) double-check your work so that you do not create a fire hazard or otherwise do something dangerous.

Adapting a fan

For this demo a small desk top fan was used. This method will also work on larger swivel floor fans or on box-style fans or any type of fan that has a housing or grating to which the material can be attached.


Fan with a metal grating or housing

Metal binder clips (easily found at stationery supply stores)
Honeywell brand Activated Carbon Pre-filter No. 38002 (The front of the box reads “Universal Replacement Pre-Filter”. The charcoal sheet measures approximately 16 inches by 48 inches when unfolded.)

Note re materials: The Honeywell carbon filter comes wrapped in cellophane with two pieces of Velcro-style tape which hold it together during shipping. The filter should be easily found at a home hardware store such as Rona or Home Depot or any store that sells Honeywell brand air cleaners. Home Depot carries it in my area for approximately $17.00.

Step 1:

Cut a piece of charcoal fabric about 2 inches larger than the widest part of the fan's housing/grating. Cut it as shown below using scissors. Don't worry about the cut being perfect. If you make the cut too long, you can use a stapler to staple the fabric together again.

Step 2:

Wrap the fabric around the rear of the fan as shown here:

Step 3:

Tug the charcoal fabric so it overlaps, clipping it with a binder clip to hold it in place. If you are using a larger fan you may need to use 3 or 4 clips to hold it in place.

Step 4:

Check your work. Make sure the motor isn't overheating!

Filter for a Vertical or Horizontal Sliding Window


1 Honeywell brand Activated Carbon Pre-filter No. 38002
1 box-style fan (optional)

With Fan

Tuck two layers of the charcoal filtration material against the screen in the window. I tuck it into the channels where the window slides and it stays there well enough without taping. You can also tape the edges of the foil to the edges of the screen with a safe-for-you tape, if necessary. I like to use aluminum foil ducting tape for such projects as the tape is inert. The adhesives of the tape will be adsorbed by the charcoal in this case, so it should be ok. As always, of course, what is tolerable for one, may not be so for another, so use your best judgment.

Place the fan on the window sill and lower the window to hold it in place. If you did not tape the filter material, double-check and adjust the charcoal material to ensure it covers the screen entirely.

The fan I used is old enough that offgassing wasn't an issue, even though the housing on it is hard plastic. If I were buying a new fan to do this project, I would purchase one with a steel casing. They can be purchased at Sears and Home Depot or other stores which carry such items.

Without Fan

Note: If you are not going to use a fan to draw air into the room, then two layers of the charcoal material may be too thick to allow air to move through easily, especially in summer. One layer works adequately without a fan to allow some air to move through, while still filtering the air.

CAUTION: Be sure to check the fan does not overheat. Please have someone knowledgeable (if you are not) double-check your work so that you do not create a fire hazard or otherwise do something dangerous.

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