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

How to Make a Furnace Filter to Filter VOCs

I make my own furnace filter of non-toxic materials to replace the standard one normally used. As with everything, what works for me, might not work for others. Please test everything and make sure you tolerate the materials, if you should decide to try this.

Please have someone knowledgeable (if you aren't) double check your work so that you don't create a fire hazard, create too much "drag" on your furnace motor, or otherwise do something dangerous.

This is how I did it:

*wire shelving
few inches of aluminum tape
spring-loaded metal paper clips and
1 Honeywell brand Activated Carbon Pre-filter No. 38002
particulate filtration material, if necessary or desired

*NOTE: the type of shelving I used has a baked-on enamel type of finish. Be careful not to purchase the type that is coated in vinyl as it will offgas.

The filter comes wrapped in a type of cellophane or plastic. It has two pieces of Velcro tape attached to keep it folded in the box, as can be seen in the picture below. There is no glue or adhesive on the Velcro that I can determine and it is easily removed. I don't know what form of activated charcoal or other ingredients are in the Honeywell Pre-filter. I tolerate it, but others might not. As always, your mileage may vary. The pre-filter should be easily found at a home hardware store such as Revy or Home Depot and Sears carries them in some areas.

This is what the Honeywell Pre-filter looks like both in and out of the box.

Wash the wire shelving and the paper clips to remove any residual oils which may be left from the manufacturing process.

I had some wire shelving already but the sizes were too small for the opening so I taped two together with aluminum foil tape. To determine the size of the shelving I needed to fit the opening, I used a regular filter from the furnace to measure by.

Close up of taping:

I add a layer of charcoal material and a layer of particulate filtration material to help keep outdoor dust down. Once the materials are in place, clip them to the shelving using small metal spring-loaded clips on the edges as shown below.

Insert in place of regular filter. Be sure to place the shelving side of the filter so it faces towards the furnace. This will give the materials a brace or framework so they aren't pulled into the furnace.

When it comes time to change the filter, simply unclip the paper clips and add new materials.

Back to top