How to Select a Furnace Filter

Instructions

• 1

  Select the type you prefer. There are four primary types: fiberglass, electrostatic, allergy and ionized. Fiberglass filters consist of a fine mesh of fiberglass. They generally filter only large particles like dust and soot. Electrostatic filters consist of a metal-mesh screen that stores static electricity. The static electricity draws passing dust and pollutants from the air. They, too, only filter large particles like dust. Allergy filters consist of high efficiency particulate absorbing (HEPA) filters. Manufacturers rate HEPA filters as the best filters for filtering large and small pollutants. They successfully filter out 99.9 percent of dander, dust, pollen or cigarette smoke and work best for people with breathing sensitivities. Ionized filters consist of tiny electrical "nodes" that magnetize pollutants. These magnetized particles stick to the filter, work almost as well as HEPA filters and work on pollens and viruses.

• 2

  Consider the life of the filter. Fiberglass filters, for instance, last up to one year, and you simply throw them away when they become clogged. You must clean electrostatic filters regularly once per month. HEPA filters last from 3 to 6 months. You must also clean ionized filters regularly once per month.

• 3

  Compare costs. Fiberglass filters generally come 3 or 4 per pack and cost between $50 and $75. HEPA filters cost from $40 to $100. Electrostatic filters range from 15 square inches to 20 square inches and cost between $15 and $45 each. Ionized furnace filters do not come with replaceable filters. Instead, the entire furnace filter operates as a ionizing filtering machine. Ionized furnace filters require less ongoing maintenance costs, but the initial cost ranges from $100 to $500. If you can't install an ionized furnace filter yourself, you will have to pay a specialist to install it for you. Hourly rates for specialists can cost between $60 to $100 per hour. All of these fees are based on 2010 prices.