How A Gas Furnace Works

There are a lot of ways that people can heat their homes during the colder months of the year but there is perhaps no better way then by using a forced air gas furnace. They offer so many benefits to those that use them; they are energy efficient, clean the air in your home, fill the rooms they go into completely with heat and they can even have an air conditioning unit attached to them too for year round comfort. Although they are widely popular, not many people really know how a gas forced air heating system really works. Here is an overview of how a gas furnace works.

Four Main Components of a Gas Furnace

In order to understand fully how a gas furnace works you must first be familiar with the system components. The main parts of a gas furnace system are as follows.

Combustion Chamber

This is the heart of a gas furnace systemas its where the heat is produced to keep the occupants of your home comfortable when its cold. There is a gas feed line to the main part of the unit that produces the combustion which provides the heat source for the system. The heat is then picked up to be moved around the house by forcedair in an area called the heat exchanger. In some systems the combustion chamber can also be adapted to do such things as provide unlimited hot water to the home also.

Air Circulation

It was mentioned above that air is the means by which the heat that the system generates is spread throughout your home. The air flow is created by a large blower that is built into the system. This blower both sucks the air into the system that is needed to help with combustion and circulates the heated air throughout the house. The air also has to pass through a series of filters which help purify the air in your home as the system is working too.


One of the main structural parts of how a gas furnace works is the extensive duct work that runs throughout your home. This ductwork is how the air supply gets to your gas furnace and also how the warm air is brought to the individual rooms in your home.

Electronic Controls

These are what make a gas furnace the convenient way to heat your home that it is. You will either have electronic thermostat controls or more sophisticated electronic controls that set the temperature and can even do such things as control the heat to individual rooms or turn the system off and on at set times.

Now that you know the individual components of a gas furnace then its much easier to understand how a gas furnace works. It simply pulls in outside air into the system and then that air is mixed with the gas supply to make combustion. Once that is done, the blower then distributes the heated air throughout the home to keep you and your family warm at those times of year when you really need to warm up your home a bit.