Ventilation Duct

A ventilation duct is a channel that distributes air within a building's HVAC system. Ducts carry supply air from the air handling unit to living spaces and return exhaust air from kitchens, bathrooms, and utility rooms back to the unit. Ducts are typically made of galvanized sheet steel and can be round or rectangular in cross-section.

Over years of operation, dust, grease, pollen, and other particles accumulate on the interior surfaces of ventilation ducts. This buildup restricts airflow, reduces the efficiency of the ventilation system, and degrades indoor air quality. In kitchen exhaust ducts, grease deposits also create a fire hazard. Studies have shown that dirty ducts can harbor allergens and microorganisms that are then circulated throughout the home.

Finnish building authorities recommend professional duct cleaning every 5 to 10 years for residential buildings, and more frequently for kitchens and commercial spaces. Professional duct cleaning uses rotating brushes and powerful vacuum equipment to remove deposits from the entire duct system. The cleaning should include all supply and exhaust ducts, diffusers, and the air handling unit itself.

Signs that your ducts need cleaning include increased dust on surfaces, reduced airflow from vents, unusual odors when the ventilation runs, or allergy symptoms that worsen indoors. If you notice any of these, schedule a professional duct cleaning to restore optimal ventilation performance and indoor air quality.