Once upon a time, more or less all gas furnaces operated in a similar manner, which was both a positive and a negative thing. On one hand, it meant that homeowners stood a better chance of understanding just how their furnace worked. On the other, the lack of diversity meant home heating wasn't always as efficient as it could have been.

Recent years have seen the introduction of a slew of new furnace styles. A selection of furnaces allows homeowners to select the optimal system for their home — provided they understand the full range of options. If you would like to learn more about today's gas furnace options, read on. This article will zero in on the exciting potential of condensing furnaces.

Furnace Basics

Before delving into what makes a condensing furnace unique, a quick overview of gas furnaces in general may be helpful. Natural gas enters the furnace through a supply pipe, its flow controlled by the gas valve. The valve allows gas to flow into the burner chamber, where flames ignite it, generating heat.

The process of combustion creates more than just heat, however. It also creates a variety of noxious exhaust gases. For this reason, the air in the combustion chamber cannot simply be sent out into your home. Instead, the exhaust passes into the component known as the heat exchanger, which is made up of a series of long curving pipes with thin walls.

Air from your home circulates around the exchanger, absorbing heat in the process. Your blower system then pushes this heated air through a filtration system and out into the rooms of your home.

Condensing Furnaces

A condensing furnace differs from a traditional furnace in one key regard: rather than containing a single heat exchanger, it possesses two. Normally the furnace exhaust would pass out of your house through the flue pipe after moving through the heat exchanger. The problem with this is that such exhaust still contains a certain amount of heat.

A lot of energy is wasted when this heat escapes from your home. A condensing furnace allows you to harness this energy, making your system more efficient, while also keeping costs down. After the air from the combustion chamber passes through the first combustion chamber, it flows into the next one. With two combustion chambers, the circulation system has more time to extract and pass on the heat.


As noted, the chief benefit of a condensing furnace lies in its incredible efficiency. A traditional furnace operates with an overall energy efficiency of around 80 percent. That means that 20 percent of the heat being generated never makes it to your home. A condensing furnace, on the other hand, boasts an efficiency as great as 98 percent.

Condensing furnaces possess another key benefit in that they feature fully sealed combustion chambers. This construction upgrade will help you in two ways. For one thing, it means that your furnace will not have to draw combustion air out of your home. The energy it requires to do this tends to reduce overall efficiency.

Instead, combustion air flows into a condensing furnace from outdoors. As a result, the warm air in your home will remain right where it belongs. This feature also reduces the risk of what is known as make-up starvation. This phenomenon occurs when a furnace can't create enough negative pressure to draw in combustion air.

For more information about whether a condensing furnace makes a good choice for your home, please don't hesitate to contact the pros at A-1 Finchum Heating & Cooling. We can help you decide on a furnace that will suit you best.