Sorting out Home Furnace Filters: How to Choose the Right One

All the world’s a stage, and some of the best shows can be found at the furnace filter aisle of the neighborhood big box store. With a sea of sizes and selection as a backdrop, the players mill around mumbling incoherently. Listen closely, and words like “micron” and “allergen” and “electrostatic” can be heard between the moans, sighs, and facial contortions. Sadly, these pour souls are store employees.

The science behind home filtration has come a long way, baby! Originally designed to help protect the HVAC (Heating, Ventilation, and Air Conditioning) system, today’s furnace filter is on the front line in the battle to improve indoor air quality. Selecting the right filter is a balance between health, expectations, budget, and possibly sanity.

Spun Fiberglass
At a few dollars each, these are the cheapest and most common type of furnace filter. They block most of the large dust particles, but smaller allergens, like pollen and mold spores, will pass right through. Because they are the thinnest of all filters, they are best suited for lower quality builder grade systems that cannot handle a thicker filter media. A spun fiberglass filter should be changed monthly.

Washable/Electrostatic
Slightly more effective than a fiberglass filter, the attraction of a washable filter lies in long term savings. The initial cost is around $25, but they last for years. The downside is in the washing. In dustier climates they should be cleaned monthly, and that’s not practical for the typical busy homeowner.

Pleated Media
More surface means more filtration. A pleated filter combines a thicker filtration media to catch more particles, with pleats to increase the overall working surface, making it an effective and popular option. The cost is about $15, and they can last up to three months, depending on climate conditions. The thicker media may reduce the efficiency of builder grade systems.

Electronic Air Filters
For people with severe allergies or similar health related issues, the benefits of an electronic air filtration system might justify the initial cost of $700 or more. Using electromagnetic attraction, they can eliminate pollen and mold spores as well as many airborne viruses.

The most common HVAC maintenance and repair issues can be traced back to filter neglect. So whatever the choice, remember to clean or replace it often. Now, back to the store- there’s new guy starting today, and I’ve got front row seats!

Dust Reducing Tips

Use a good furnace filter and change it often
Use an efficient vacuum (Central vac and HEPA are great)
Avoid smoking the house
Keep pets cleaned and groomed, and brush them outside
Remove footwear before coming inside
Keep windows closed
Reduce drafts
Choose tile or wood flooring instead of carpet