Frequently asked questions about furnace filters:

1. What is the difference between fiberglass and pleated filters?

Fiberglass filters were designed to protect the furnace and air conditioning system. Pleated filteres are designed to improve indoor air quality by trapping small airborne particles, including pollen and mold.

2. What does MERV rating mean?

A MERV (Minimum Efficiency Reporting Value) number indicates the efficiency of a filter to trap particles from 3.0 microns to 10.0 microns. The higher the MERV rating the more efficient the filter.

MERV 6 = 35-50% efficient

MERV 8 = 70-85%

MERV 11 = 85-95%

3. Are "electrostatic" filters as good as the pleated filters?

They are slightly better than fiberglass filters but are only 15-20% efficient.

4. how often should I change the gilter for my furnace and/or air conditioning system?

Fiberglass filters = once a month

Pleated filters = every three months