Can Duct Cleaning Affect the Functioning of Furnaces?

Duct Cleaning Claims

• Furnace ducts bring cold air to a central point in the home, which is your furnace. They then move the heated air to other areas of your home. Ducts can easily gather dust and debris that may be floating in your heated spaces. Duct cleaning service providers claim that regular cleaning of these systems can provide better indoor air quality, reduce allergens and molds, eliminate dust, increase airflow and heating capacity and reduce energy costs. However, according to the Canada Mortgage and Housing Corporation (CMHC), such claims may be unwarranted.

Reality

• In the 1990s, the CMHC and the U.S. Environmental Protection Agency (EPA) tested the results of furnace and duct performance before and after cleaning. They found “little or no discernible differences in the concentrations of house airborne particles or in duct airflows due to cleaning.” In other words, duct cleaning does not affect the functioning of furnaces. Metal duct work does not create dust. Most of these particles are tracked in from the outdoors and will be in the air, the duct work and furnace, whether the ducts are cleaned or not. The EPA further asserts that duct cleaning has never been shown to prevent health problems. This is because the light dust present in ducts or the home does not pose any health risks.

Cleaning

• The EPA does recommend cleaning air ducts under certain circumstances. These include if the ducts contain insects or rodents or evidence of their habitation, such as droppings. If the air registers are releasing dust into the rooms, this indicates high concentrations of particles in the duct work, which would require cleaning. And if you see mold growing in or around the ducts or other parts of the furnace, you’ll need to hire an expert to ensure that this is indeed mold and not just an accumulation of dirt.

Furnace

• There are several proven ways to improve your furnace's performance, according to the EPA. The least expensive is to check the furnace filter every month, especially during periods of heavy use. Dirty filters can slow airflow and need to be replaced. Having your heating system tuned up once a year can also improve its efficiency. Sealing heating duct seams and connections with mastic or foil tape can prevent air leaks. Finally, a programmable thermostat is especially useful if you leave your home during a set time during the week. You can automatically lower the temperature at those times or when you sleep and then raise them when you return home or are active.