At Issue: As local temperatures dip with the approach of winter, many central Illinois residents will be spending more time indoors.

Local impact: Central Illinois homeowners will be increasingly reliant on their heating, ventilation and air conditioning (HVAC) units to heat their homes during the colder months. Changing furnace filters regularly is imperative not only because it maintains the air quality in the home, but also because it prolongs the life of an HVAC unit.

Between snow that tempts sledders and snowball-wielding warriors, frozen ponds that attract skaters, and the need for some traditionally-minded local residents to harvest a Christmas tree the old-fashioned way, winter in central Illinois does not lack for outdoor activities. But an hour or two in the brisk winter air tends to drive all but the hardiest indoors, to the comforts of football on a big-screen television, a roast turkey or a family gathering in a centrally-heated home. But if the furnace heating that home has a dirty filter, it may be releasing dust particles and allergens into the home.

A clean furnace filter not only helps preserve indoor air purity, it also extends the life of a home’s HVAC unit, keeps energy costs down, and keeps the entire heating and cooling system clean. Brandon Jasinski of Creve Coeur, a general manager at Menards home improvement store in Washington, recommended changing furnace filters every one to three months, on average.

“It depends on how often you use your furnace, and your sensitivity to dust particles and allergens,” he said. “Somebody who has multiple pets or allergies might want to change their filters more frequently, but if you don’t have a lot of those issues, you might make a filter last three months. It’s a good idea to write a date on the edge of your new filter before you install it: either the date of installation or the date you need to replace it. That’s just something to serve as a reminder.”

Jasinski added that furnace filters range in price from $2 or $3 to $20. Changing the filter is generally an easy process. 

“There’s an access panel a homeowner can open, and it’s usually easy to get at and open,” he said. “Then it’s just a matter of sliding the old filter out and sliding the new one in.”

John Sullivan of Morton changes his furnace filter every six months and is aware of how a small expenditure and a simple procedure keeps his HVAC unit running efficiently and keeps his energy bills down. The time of year, he believes, does not have any significant impact on HVAC use.

“You’re running your furnace more in the winter, but I don’t know if you use the air handler more in the winter than you would in the summer, when you’re running your air conditioner a lot,” Sullivan said. “A clean filter is something you want in your unit year-round.”

According to Mike Quick of Morton, the frequency with which a homeowner needs to change furnace filters depends on the type of filter used. He changes his own on an annual basis, which he believes to be sufficient.

“I had a new furnace put in eight years ago,” said Quick. “With my old furnace, I was using one-inch thick fiberglass filters, which I changed monthly. With the furnace I have now, I use four-inch thick pleated filters. They can last a year, because they have a larger area to collect dust and allergens and for air to circulate through.”