Condensing gas furnaces deliver a fuel-to-heat conversion of more than 98 percent and enhance both home comfort and indoor air quality. Learn how the components of a condensing furnace combine to offer a heating system that’s far superior to a conventional furnace.
The secondary heat exchanger
The key component that makes a furnace a condensing furnace is the secondary heat exchanger. A conventional furnace has one heat exchanger, which allows heat to escape up the chimney. In a condensing furnace, the hot exhaust gases flow into the secondary heat exchanger before venting. The hot exhaust gases are condensed into a cool liquid and vapor, while nearly 100 percent of the heat is extracted for use in your home. The cool vapor (about 100 degrees) flows inside a plastic exhaust pipe that is vented through the wall or roof. The acidic liquid is drained away.
Modulating gas valves
Modulating (or two-stage) gas valves are another boon for fuel efficiency. Conventional gas valves (single-stage) are either on full blast or off. Modulating gas valves automatically adapt to your home’s actual heating needs. For instance, if you turn back the thermostat during work hours to save energy, when you return home the temperature may be 10 degrees below your comfort level. A modulating gas valve quickly heats your home to temperature and then reduces fuel flow and heat to maintain longer, more efficient heating cycles.
The variable-speed blower works beautifully with modulating gas valves and on the same premise: operating at ideal capacity to match real-time heating needs. The variable-speed blower delivers slower, smoother and longer airflow cycles. This maximizes home comfort with even heating. In addition, it cycles indoor air through the air filter or whole-house purification system many more times. The variable-speed blower is quiet and durable. It also complements a zoning system.
The condensing furnace is safer to use than a conventional furnace. A sealed-combustion chamber employs direct-vented air from outside your home for fuel combustion, which is more efficient than using warm ambient air and helps prevent back-drafting in your home.
For more information about condensing furnaces, contact Blanton’s Heating & A/C. We’ve proudly served homeowners in the Fayetteville area for more than 60 years.
Our goal is to help educate our customers in Fayetteville, North Carolina and surrounding areas about energy and home comfort issues (specific to HVAC systems).