Indoor air quality is important because it directly impacts your health and comfort. Besides providing heating, an efficient furnace should maintain quality indoor air and protect households from respiratory conditions. Unfortunately, a worn gas furnace does the opposite. Over time, it can lower the air quality in your home and cause health hazards. If you have a worn gas furnace or heating system, watch out for the following forms of air contamination in your home.

Carbon Monoxide Leaks

Carbon monoxide (CO) is a by-product of the combustion process in a gas furnace. Normally, the gas does not interact with the air supplied through the ductwork. However, worn components in the furnace can cause the gas to leak into the air, leading to carbon monoxide poisoning. CO leaks usually occur for the following reasons:

• Worn flue pipe: The flue pipe is the duct that vents exhaust gases from the furnace to the outside. Cracks in the flue pipe cause carbon monoxide to leak into the home and mix with the air.
• Cracked heat exchanger: A furnace heat exchanger separates the combustion process and exhaust gases from the air. Cracks in the heat exchanger can cause CO to leak into the air in your home.
• Poor system design: A poorly designed system with improper venting can cause combustion gases to mix with the home's air.

Carbon monoxide is odorless, but other exhaust gases aren't. Therefore, if you smell gas in your home, shut off the furnace immediately and call for repairs. Look out for soot buildup in the furnace, which is a telltale sign of leaking exhaust gases.

Condensation and Mold Growth

The leading cause of humidity in ducted heating systems is condensation buildup in the ductwork. Condensation buildup occurs due to:

• Clogged ducts and filters
• Poorly sealed ducts
• Lack of or damaged duct insulation

When the furnace is on, the air moving through the ducts is warmer than the surrounding environment. Heat exchange between the ducts and their surroundings causes condensation inside the ducts. The humid air encourages mold growth in the ductwork. Consequently, mold spores are blown into the home and inhaled together with the air. You should seal and insulate the ductwork to improve air quality.

Dust and Allergens in the Home 

Leaks in the ductwork can introduce dust, pollen, and other allergens into your indoor air. A poorly vented furnace can also introduce exhaust gases and dust into the air. If your indoor air is triggering allergic reactions in the household occupants, you need to check the ducts and furnace vents. Also, replace your furnace air filter if it is worn.

Is your furnace affecting the air quality in your home? Contact a heating contractor for troubleshooting and repairs.

For more information on furnace repair, contact a professional near you.