Alliant Energy encourages changing or cleaning filters to keep furnaces running efficientlyChanging or cleaning a furnace filter is a maintenance task many homeowners forget or overlook. But this simple chore is one of the easiest ways to keep a furnace running efficiently."Failing to check the filter regularly can be costly, "said Dave Rogers, a trade account manager with Alliant Energy. "Dust and dirt can work their way into the blower and coil assemblies, reducing the furnace’s operating efficiency and eventually damaging the motor."Up to half of all furnace service calls are related to problems caused by dust and dirt clogging up vital system parts. "Replacing a filter takes just a few minutes and can save your furnace from a lot of wear and tear — and costly repairs," adds Rogers. Disposable fiberglass filters are inexpensive and easy to use — just pull out the used filter, throw it away and put in a new one. If disposable fiberglass filters are used, it’s important to change them every month, because the dirtier they get, the less effective they are. Most filters of this kind are effective at blocking only 10 to 15 percent of airborne particles even when they’re new. By upgrading to a 1# pleated filter you will get 25 to 30 percent particle blockage. Many people are switching to reusable electrostatic filters. These cost a little more — between $50 and $80 each, but they can last up to five years, and they’re three to five times more effective than fiberglass disposables. Reusable electrostatic filters should be cleaned at least every other month — pull it out, spray it off in the sink, let it dry and replace it. "Another option is the high-efficiency pleated filters," said Diane Hanson, a trade account manager with Alliant Energy. "They’re disposable, but they trap up to 75 percent of air particles, and they can last anywhere from six months to a year."In addition to replacing or cleaning furnace filters, it is recommended that homeowners clear snow and ice away from the furnace’s intake and exhaust vents outdoors. If the vents become blocked, dangerous carbon monoxide fumes can back up into the house, and the furnace could shut down" An annual checkup by a qualified service technician is also a good idea — especially if you have a natural gas system," reminds Leo Udee, a trade account manager with Alliant Energy. "The technician will check the flues and temperature settings, examine the heat exchanger for cracks, and check the safety mechanisms. A $50-$100 annual tune-up can reduce your annual heating cost by five percent."If your furnace is more than 10 years old, upgrading to new high-efficiency equipment can substantially reduce energy costs. Alliant Energy — Interstate Power and Light offers its residential and small business customers in Iowa and Minnesota a minimum rebate of $200 on qualifying heating systems. To learn more, call Alliant Energy at 1-800-ALLIANT to request the free PowerHouse brochure Heating Your Home, or look for it on the Internet at www.powerhousetv.com