Good housekeeping should not be limited to the filters, the blower compartment and burner chamber. It should extend to the ducting and cold air return as well. This is more of a health issue than one that relates to furnace efficiency. This is of special importance to people with respiratory ailments or allergies.

Dust, dirt, pollen, animal dander and other airborne contaminants are pulled into the ducting each time the blower is operated. These contaminants build up inside the ductwork over time and can make the duct system an ideal breeding ground for mold spores, bacteria and foul odors.

Duct cleaning is not something that can be done effectively by the do-it-yourselfer. The process which costs approximately $300 to $500 for the average home uses a powerful portable vacuum along with an "air snake" which is fed through all of the ducting. The air strips the interior of the ducts and feeds the debris into the special vacuum. This process should be performed every one to five years depending upon accumulation. Check with a heating contractor for a referral.

By MORRIS and JAMES CAREY, For AP Weekly