The more you know about the heating and cooling equipment in your Layton, UT home, the easier it will be to maintain it. Heat exchangers rank among the most important components in residential furnaces. Not only do they handle the transfer of heat, but they also determine furnace efficiency and safety. When they stop working or develop adverse changes in their structural integrity, residents are at risk of carbon monoxide (CO) exposure and poisoning. The following is everything you need to know about heat exchangers and their role in the heating process.
Heat Exchangers Extract Heat From Combustion Gases
In a fuel-fired furnace, natural gas, propane, or heating oil is burned in the combustion chamber. This process heats the walls of heat exchangers, which then transfer this heat to the cool air passing through them. As hot combustion gases move through this component, their heat is extracted too. Heat exchangers then route conditioned air into HVAC air ducts and exhaust gases into venting systems.
Some Furnaces Have Two Heat Exchangers
For many years, all furnaces had a single heat exchanger. This greatly limited their efficiency. When exhaust gases leave a heat exchanger, they often retain a fair amount of residual heat. With a less-than-efficient furnace design, this heat escapes the building along with carbon monoxide and other exhaust gases.
In a modern, high-efficiency furnace, residual heat is extracted from the exhaust that exits a primary heat exchanger in the unit’s secondary heat exchanger. As much as 12% more heat is added to what was already extracted.
Annual fuel utilization efficiency (AFUE) ratings measure furnace efficiency. AFUE ratings determine what percentage of the oil or gas that a furnace burns is converted into heat. A furnace with a single heat exchanger might have an AFUE rating of just 86% while a high-efficiency furnace with two heat exchangers can have an AFUE rating as high as 98.5%. With a second heat exchanger limiting energy waste, it’s possible to reduce heat losses to just 1.5%.
Why Heat Exchanger Problems Are Dangerous
Carbon monoxide poisoning is the greatest risk associated with damaged heat exchangers. When these components crack, they leak CO gas into the indoor environment. This gas is both odorless and colorless. Limited, short-term exposure can lead to headaches, confusion, nausea, and vomiting. If CO leaks remain undetected or if indoor CO concentrations ever become too high, exposure could lead to death.
To limit the risks of CO exposure and poisoning, all homes with fuel-burning appliances must have CO detectors installed. It’s also important to remain up-to-date with all manufacturer-recommended maintenance. Skipping annual furnace service will limit the efficiency of your heating equipment, create an increase in your home energy bill, and diminish your indoor air quality. However, if you have a fuel-burning furnace with one or more heat exchangers, it will also create a number of major health and safety risks.
How Long Do Heat Exchangers Last?
Most fuel-burning furnaces are expected to last between 15 and 20 years. Moreover, many of these heaters come with 10-year limited parts warranties and 20-year warranties on their heat exchangers. These components are built to last and should remain functional and intact throughout the entirety of a furnace’s lifespan. However, the all-metal composition of heat exchangers makes them subject to temperature-related expansion and contraction. In homes that run their heating systems all of the time, constant expansion and contraction often causes accelerated wear.
Should You Replace a Heat Exchanger or Replace Your Furnace?
If your heat exchanger has failed, you may be wondering whether to replace it or simply have a new furnace put in. The answer lies in the terms and conditions of your existing warranties and your furnace’s age. If your furnace is still under its labor warranty or if it came with a 20-year warranty on its heat exchanger, replacing this component alone will prove the most cost-effective choice. However, if paying for a new heat exchanger out of pocket, it’s important to consider the additional wear that your aging furnace has already sustained. Installing a new heat exchanger now could leave you replacing other major components soon after.
We’re committed to helping homeowners in Layton, UT make informed decisions about their HVAC systems. We offer furnace, boiler, heat pump, and air conditioner installation, maintenance, and repairs. We also provide indoor air quality services, water heaters, and water softener service. To schedule an appointment, contact Smedley Service now.
