A bit of furnace knowledge can be helpful if problems with your heating system occur and you need to summon professional HVAC service. It’s also a benefit if you’re shopping around for a new unit and considering your options. Finally, furnace knowledge is helpful to understand safe operation of the system.
What follows in a nutshell is a basic description of furnace functions and components and how they interact to keep your home comfortable all winter long. It’s furnace knowledge you’ll be happy to have.
- Natural gas flowing into your furnace is regulated by an internal gas valve. In residential furnaces, gas pressure is surprisingly low—typically only about 1/2 psi (pounds per square inch).
- On a signal from your home’s thermostat, the gas valve opens, and gas entering the furnace burner is mixed with air and ignited by an electronic igniter. The blue gas-burner flame burns at nearly 3,500 degrees Fahrenheit.
- Heat produced by the burner rises into the heat exchanger, a critical component made of stamped steel or copper. The heat exchanger transfers heat generated by the burner flame into the filtered system airflow that circulates throughout the house. At the same time, the heat exchanger contains dangerous fumes generated by the combustion process, including deadly carbon monoxide. Fumes are safely exhausted up the furnace vent pipe.
- Hot air leaving the furnace is typically between 140 degrees and 170 degrees. An electric blower located in the air handler propels the heated air into the network of HVAC ductwork that extends throughout the house.
- Rectangular sheet metal ductwork forms two independent networks leading to room vents. Supply ducts deliver warm air to supply vents in each room, while separate return ductwork removes air from rooms and returns it to the furnace. An average residential system incorporates 30 to 90 linear feet of ductwork.
- Return airflow passes through the system air filter and then enters the heat exchanger for reheating as the heating cycle continues.
The experienced staff at Paitson Bros. is happy to share furnace knowledge and answer any questions. It’s been our business and pleasure to serve Terre Haute residents since 1922.
Paitson Bros
1 (812) 232-2347
Serving the Wabash Valley, IN Area Since 1922