The furnace is the most important component of a central heating system. It houses all the working parts. So when you replace the furnace, you replace the vital operating parts of your heating system. It is by choosing from among the different models and brands of furnaces available that you determine the quality and cost of your home’s heating for years to come.
The furnace is part of a forced-air system. Warm air is forced, or blown, through a system of air ducts to each of the rooms in the house. House air drawn into the furnace passes through a filter, where dust and other small particles are trapped. A blower unit blows the filtered air through the furnace, and the air absorbs heat.
GAS HEAT
If it is a gas furnace, the heat is supplied by the burning of natural gas. A mixture of gas and air flows into the burner and is ignited by the pilot. Combustion occurs, and warm air from the burner flame rises to fill a chamber known as a heat exchanger. The heat exchanger becomes hot. House air passing around the heat exchanger absorbs that warmth, continues into the air ducts and the heat is distributed through the home. The by-products of combustion pass upward through a venting system and escape through a vent in the roof.
ELECTRIC HEAT
If the furnace is electric, heat is generated by an electric heating element. Electric current traveling through the element creates heat. By the heat transfer processes called conduction and convection, heat is transferred into the air stream and flows through the air ducts into the rooms of the home.
THE THERMOSTAT
Whether you heat your home with gas or electricity, a wall thermostat will be installed. This measures room temperature and turns the central heating system off or on as the temperature rises or falls to designated levels. Careful location of the thermostat is an essential consideration in maintaining maximum comfort levels in your home.