If you don’t remember ever having your ductwork cleaned or if you haven’t within the past 2-3 years, it is probably time. If your ductwork has been cleaned in the past, you will typically find access doors installed on the supply and return plenums near the furnace.

Remove a register grill – ones on the floor or near the floor are easiest to remove (often no screws) and peer inside with a flashlight – check several areas for a representative sample.

Do people in the house suffer from allergies, asthma, or other respiratory problems?

Do you experience nausea, headaches, itchy eyes, etc. while at home?

Do you have pets in the home and/or excessive dust on furniture and horizontal surfaces?

If you answered yes to any of the above, then it is time.