I lived in my house for over twenty years and never paid any attention to the duct system.
While I was conscientious about changing the filters in the air conditioner and furnace, it never occurred to me that the duct system would need service.
Every fall, I scheduled professional maintenance for the furnace, and every spring, I called for upkeep for the air conditioner. I’m not sure why the HVAC contractor who handled the proactive services never recommended an inspection of the ductwork. It wasn’t until we started having complaints with indoor air quality that I finally took notice of the ducts. There were unpleasant odors and allergens spewing from the supply vents. The furnace seemed to be running nonstop and my heating bills were much higher than normal. Despite paying extra every month, the house felt downright chilly. I kept raising the thermostat setting, but the heating system wasn’t able to keep up. Certain rooms were much colder than others. I finally called for furnace repair. The technician inspected the heater and found no problems. He then tested the duct system and discovered that airflow was significantly restricted by a buildup of debris. There was a considerable accumulation of dust, mold growth, mildew, construction debris, bacteria, bugs, webs and even a couple of decomposing rodents. Every time the air conditioner or furnace started up, the air was passing through the network of pipes and picking of harmful contaminants. These pollutants were circulated throughout the house and getting breathed in by my family. Not only was the dirty ductwork costing me a fortune and adding to the wear and tear of the heating and cooling system, but it was the source of a health risk.