What is the Best Furnace Filter?

As you walk down the aisle with towering boxes of furnace filter to your left and right you wonder, what furnace filter is the best for my house? Pleated, Washable, Micro Allergen, Dust and Pollen Reduction, does it matter? Well, making the wrong choice could suffocate your system with disastrous results.

First, a little furnace filter education. The furnace filter industry rating system is called, minimum efficiency reporting value (MERV). The MERV rating generally ranges from 1 to 16. Basically, the higher the rating, the thicker the furnace filter and more particles it can capture. Obviously a thinker one would be a better, right? Not so fast.

Thicker filters significantly restrict air flow once they become even somewhat clogged. This prevents your furnace from moving as much air as it was designed to do, which causes it to work harder and possibly malfunction. Also, consider a very important but often overlooked piece of this puzzle, the duct work. Unfortunately, most residential ductwork is not properly designed to handle those thick furnace filters. And what about the claims they can last for up to 3 or even 12 months?

Those recommendations are usually based upon perfect lab tests and not so much the real world. You have to really know your home environment. Do you have pets, are you a smoker, do you leave the windows open, and how dusty is your home normally? The answers to these questions not only help you determine a furnace filter but how often they need to be replaced.