If you’re a homeowner, it’s especially important, as the days and nights get chilly, to make sure your heating, ventilating and air conditioning system (HVAC) is in optimal shape for the long winter ahead. This important system is going to be moving large amounts of air through your ducts and into your home. Coupled with the amount of time you’re going to be spending inside over the next few months, you’ve got a great reason to ensure healthy indoor air quality.

During the winter, one of your most important chores is going to be changing your furnace filters regularly. These essential parts of your HVAC system filter most of the particles you breathe in your home, which come from a variety of sources, including:

  • dust on floors or other surfaces that is disturbed by activity;
  • dust generated by burning candles, cooking, doing laundry, etc.;
  • hair and skin flakes from humans or pets; and
  • particles from outside which come into your home with infiltrating air.

But how often should you replace your furnace filter? And how do you know which is the best filter to use?

As your filter collects particles, it starts to get clogged. Over time, the buildup makes it more difficult for air to pass through. This causes the blower to work harder, increasing your energy bill and eventually causing the blower motor to overheat and burn out.cThat’s why it’s important you inspect your furnace filter once a month and change it every three months. Remember: this is at minimum—you may need to change it as often as once a month.

When it comes to choosing a furnace filter, there are many options.

  • Disposable fiberglass, the cheapest option, will do little more than prevent larger particles like dust, lint, and debris from gunking up your system.
  • Disposable pleated filters are popular. Made from polyester or cotton paper, they can remove some small particles like spores and mites, but they need to be changed frequently to avoid clogging and taxing your HVAC system.
  • Disposable electrostatic contain self-charging electrostatic cotton or paper fibers that attract and trap small particles.
  • Permanent electrostatic are similar to their disposable brethren, but have a removable, machine-washable filter that can be removed and reused for six to eight years.
  • High-efficiency pleated are made from deep 4-5″ pleated synthetic cotton and attached to very rigid metal grid to prevent leaks or fluttering. Can be very expensive.