Furnace The wonderful invention of furnaces, an appliance that generates heat, comes from a centuries-old idea. One of the earliest examples of the furnace was the hypocaust, utilized by the Romans. The hypocaust was an under-floor heating system that warmed a dwelling by supplying heat from a wood-burning fire in the basement corner. The exhaust was vented through chimneys via wall flues. Coal replaced wood as the primary heating medium in the seventeenth century and was used up until the 1940s when gas became the primary fuel for furnaces. In the 1970s, due to the energy crisis, electric furnaces gained prominence. Today, the gas furnace is one of the most popular home furnaces. A furnace can warm a house, and it has industrial applications. For example, furnaces are used in treating materials to change the molecular structure and in manufacturing steel.

How Furnaces Operate

Contemporary gas furnaces have electronic control circuitry and an external thermostat. When the thermostat requests heat, the burners light and heat the primary heat exchanger. Heated air flows through the secondary heat exchanger to the exhaust flue and chimney. The exhaust flue uses a flue draft blower for increased efficiency, while the heat exchangers transfer warmed air from the burners to the building, removing exhaust gases via the chimney. Heated air is circulated by a large blower and heating ducts.

Types of Home Furnaces

Single-stage: The single-stage furnace has only one stage of operation, on or off. Because it’s continuously running, and perpetually pumping out air at the highest velocity, it can be a bit noisy. However, they’re relatively inexpensive because they’re based on a simple design.

Two-stage: The two-stage furnace works with a choice of full speed or lowered speed, making them quieter and better able to relegate temperature.

Modulating: The modulating furnace is able to regulate the air velocity and heat output, saving energy.

The Heart of a Home

David White Services, a family-owned and operated company since 1977, offers 24/365 customer care. Our work ethic, based on teamwork, has earned us a Lennox Top 50, Circle of Excellence, and a Centurion award. We can help you with any HVAC needs, from heating and air conditioning maintenance to installing a new fireplace.