Why Is a Furnace Heat Exchanger a Big Deal?

Monday, December 20th, 2021

furnaceIf you’re like the majority of homeowners in our area, you have a gas-powered furnace in your home to keep you and your family comfortable all winter long. A furnace is a great choice, as it is a powerful and efficient source of heating. Today’s furnace models have a higher efficiency rating than those of even just a decade ago, with the highest AFUE rating (AFUE stands for Annual Fuel Utilization Efficiency) for a gas-powered furnace being 98%. Trust us when we say this is efficient heating!

In addition to your heater’s efficiency, you want to be able to rely on it’s safety, too! This isn’t to say that a heating system is inherently dangerous. However, if your furnace isn’t adequately maintained, it can become so. This is especially true when you’re using a gas furnace over an electric furnace.

The most common risk to safety when it comes to furnace use, especially an older one, is a damaged heat exchanger component. Even if you don’t currently have a problem with a heat exchanger, if your furnace is 10-15 years old, it’s time to start considering an upgrade. We’ll dive more into the “why” of this below!

What the Heat Exchanger Does

It’s first important to understand the role of the heat exchanger. This component isn’t just important to the functionality of your gas-powered furnace… it’s essential. Heat exchangers are where the combustion gases collect in order to heat up the metal walls so that air can pass over them and bring heat into your home. In other words, the heat exchanger is what’s actually responsible for the heating part of your heating system.

We’ll explain further–the heat exchanger is designed in a clamshell fashion. Combustion gases enter this clamshell-shaped component, and the temperature of these gases raises the temperature of the metal. The blower fan then pushes air over these metal chambers, and the heat is transferred to the air. Then, the air travels through your air ducts and into your home.

The metal walls of the heat exchanger are the only thing that stands between your indoor air and the combustion gases–so you might be starting to realize why it’s a problem if the heat exchanger is damaged…

Why A Damaged Heat Exchanger Can Be Harmful

Over time, natural wear and tear impacts your furnace components, and the heat exchanger is no exception. Each time the heat exchangers get hot, their metal walls expand with the heat. Then as the heat exchangers cool down, the metal contracts. After many years of this,  the heat exchanger may become prone to corrosion and subsequent cracks.

The cracks that occur on heat exchangers are very small–microscopic even. But when the heat exchanger heats up again and expands, the cracks open up and can leak combustion gases out. If your furnace is well-ventilated, this may not be a problem. However, there is one combustion gas in particular–CO (carbon monoxide)–that can be dangerous if it does make it’s way into your indoor air!

CO poisoning is very harmful, leading to illnesses and fatalies each year. The best way to prevent this danger is to invest in annual furnace maintenance, and to have CO detectors installed so you’re warned when there is exposure in your home.

For expert service on your Joliet, IL furnace, look no further than Comfort First Heating and Cooling, Inc. Contact us today! 

Continue Reading