A Look At An HVAC’s Head Exchanger

Homeowners might not be familiar with all the parts in their heating and cooling systems, but developing a general understanding of what these parts do is a good idea. Better insights about particular components allow a homeowner to identify problems when a part malfunctions. Sometimes, a failing part presents safety hazards that require immediate attention. Increased knowledge about the HVAC system and its many components could help a homeowner contact a repair service immediately and take other actions before their safety is in jeopardy.

A problem with the heat exchanger may present dire health hazards. Replacing a heat exchanger is costly, even if damage does not lead to safety risks. Here is an in-depth look at the role a heat exchanger plays in your HVAC system.

What A Heat Exchanger Does

Thermal energy refers to the energy that establishes a particular temperature. A heat exchanger is a component inside the HVAC designed to transfer thermal energy from one medium to another. These mediums are actually fluids utilized for the transfer process. Water and steam are the most common fluids used to transfer thermal energy in a heating system.

It is worth noting that a heat exchanger does not only work to warm a home. This part also works with the air conditioning system to cool particular areas inside a house. With a cooling system, refrigerant often serves as the transfer medium.

Two parts work together with the heat exchanger: the evaporator coil and the condenser coil. An evaporator coil draws heat from the interior air thanks to a blower that pushes this air over the coil. Next, the evaporator coil’s refrigerant absorbs excess heat and transfers it to the condenser coil. The condenser coil then releases the air outside. Homeowners looking for the evaporator coil may see it connected to the furnace or inside the air handler.

The evaporator coil and the condenser coil can get dirty. Routine maintenance to have these coils properly cleaned is crucial to keep your system functioning optimally.

An Example Of How A Heat Exchanger Works

Two processes take place when the heat exchanger does its job. One process happens at the bottom of the heat exchanger, while another occurs at the top. Underneath the heat exchanger, the burners send gas through an opening at the part’s underside. At the top, a blower sends indoor air over the heat exchanger. The air heats as it comes in contact with the heat exchanger, and the blower moves that hot air into the ducts. The hot air travels through the ducts and out the vents inside the home. The heated air raises the temperature to the desired level on the thermostat.

This combustion process produces exhaust gas, which is dangerous to humans. The exhaust gas must exit the home through the flue and not mix with the air inside the property. That’s why cracks in a heat exchanger are so dangerous. They create imperfections that allow gas to escape, potentially infiltrating your home and causing severe illness to those inside.

Lifespan Of A Heat Exchanger

A heat exchanger, like other parts of your HVAC system, will wear down over time. The average lifespan of a heat exchanger is 10 to 15 years. A homeowner who keeps an old HVAC system in the home and chooses not to replace it will have aging parts inside that are prone to failure. Requesting routine maintenance visits could allow an HVAC technician to determine whether the heat exchanger or another component requires an upgrade.

Even if your HVAC unit is not at the end of its service life, biannual inspections and cleanings may lead to uncovering a faulty part. A heat exchanger could suffer from manufacturer defects, making it potentially unsafe.

An Overheated Heat Exchanger: A Common Problem

If a heat exchanger suffers from overheating, it may cause damage to your entire HVAC system. In some instances, the reason for the overheated heat exchanger could be little more than a homeowner neglecting routine maintenance. For example, keeping an old, clogged filter in place could result in reduced airflow. The heat exchanger could overheat if warm air remains in contact with it.

Overheating is dangerous because the increased temperature might result in a cracked heat exchanger. If cracks occur, hazardous gases such as carbon monoxide, nitrous oxide, and sulfur dioxide may leak into the home. These harmful gases could cause adverse health reactions and even death. While a carbon monoxide detector is lifesaving in these circumstances, it certainly would be better not to have a leak in the first place.

Thankfully, HVACs have a high limit switch that could prevent the heat exchanger from overheating. The high limit switch offers a nearly failsafe feature that cuts off gas to the furnace when the temperature becomes too high. Cutting off the gas should reduce the temperature and prevent the heat exchanger from cracking. Unfortunately, a high limit switch could fail, meaning it won’t shut off the system at a critical time.

Homeowners should look and listen for problems associated with a faulty or cracked heat exchanger. Monitor your unit for abnormalities such as rust or corrosion. A rusty heat exchanger is prone to suffering cracks, so corrosion is not something to ignore.

Foul odors coming from the unit would be another red flag. If the smell mimics formaldehyde, that likely indicates that cracks have already developed in your heat exchanger. A dirty furnace with soot inside it or water on the floor surrounding your furnace are two additional signs of a damaged part. Lastly, if the flames from your HVAC burner are yellow instead of blue, a cracked heat exchanger could be the culprit.

Replacing a cracked heat exchanger could be costly. Upgrading the entire HVAC system may be wise if you have an older model likely to suffer from additional wear-and-tear issues in the near future.

Learning About The Heat Exchanger

An informed homeowner is more capable of staying on top of problems with their HVAC system. To learn more about how your heat exchanger is structured, refer to the illustrations in your HVAC owner’s manual. Online videos may also provide a detailed visual guide of how a heat exchanger operates. Reviewing records of previous repairs performed by HVAC technicians will also offer valuable insight into your system.

At Absolute Air, we want to assist homeowners with their heating and cooling repair and replacement needs. Our company also provides indoor air quality, duct cleaning, and water heater services. We offer a free comfort evaluation to help our valued customers determine the best HVAC solutions for their needs. We have an A+ rating from the Better Business Bureau and a certification from TruTech.

In our area of the country, the weather can change at the drop of a hat. If you live in Morgantown, Pittsburgh, or the surrounding areas and want someone to check out your HVAC system, call Absolute Air today!

Published: March 15, 2023