Understanding How Your Home Furnace Works

Basement with furnace system

The home furnace is a machine that everybody appreciates, especially in winter, but not many understand how it works. There are three main elements to a furnace.

1. The Burner

The central element of a home furnace is the burner. This is where air and fuel are mixed to burn with maximum efficiency. Gas furnaces burn gas and air, and oil furnaces burn a mixture of oil and air. The air carries the oxygen that enables combustion. An electric furnace creates heat differently. Electricity is fed into elements that have a high resistance and get hot as they react to the electricity.

2. The Heat Exchanger

This is what is commonly referred to as the boiler. A heat exchanger is simply a coiled set of pipes that carry water through the heat of the flames. The length of the pipes increases the surface area and allows more heat to be absorbed by the water. An electric furnace is different because the heating element is inside a tube sealed inside a water tank. The element is often doubled or spiraled to create a bigger surface area to help heat the water more efficiently.

3. The Pump

The furnace pump ensures that the water is kept circulating to disperse the heat and to prevent a local build up of pressure. Normal convection does not work in the closed environment of a boiler so the pump takes over.