The term upflow in HVAC refers to how the air flows from a gas furnace into your ductwork in a forced air heating system.
By Anne Fonda
In an upflow furnace, the unit pulls in air at the bottom of the unit, passes it over one or more heat exchangers, and blows the heated air up and out through the top of the unit and into the ductwork. The basement is the most common location for this furnace installation configuration.
An upflow furnace configuration is generally more energy efficient than other configurations because hot air naturally rises. This can make the upflow installation ideal for homes in colder climates where the furnace is on more often.
A downflow furnace is the opposite of an upflow furnace as far as the direction of airflow. A downflow furnace pulls in cool air at the top of the unit and heats the air over one or more heat exchangers. Then, it releases warm air at the bottom of the unit and into the ductwork. An attic is the most likely location for a downflow furnace.
In this installation, the furnace lays on its side on the floor or base and the air flows in from one end and out the other end. A horizontal flow furnace configuration is most common in attics and crawl spaces where a vertical installation is prohibited.
The best airflow configuration is the one that works best with where you need to locate your furnace. If your home has a basement, an upflow furnace would be most efficient. If you have to locate the furnace in the attic, a downflow configuration might be best. Finally, if you need to install the furnace in a crawlspace, a horizontal configuration might be optimal.
An experienced HVAC company can help you determine the best location and airflow configuration for your furnace so that it can operate most efficiently.
There are a lot of things to consider when it’s time to choose a new furnace or HVAC system, including:
An experienced HVAC contractor can help you find the right furnace for your new or existing home.
If your furnace is aging out or repairs are costing more and more every year, it may be time to consider furnace replacement. The installed price of your new furnace will vary based on several factors including the size and layout of your home, where you live, the furnace you choose, and the complexity of the installation process. Contact your local American Standard dealer for a custom quote for furnace replacement costs for your home.
A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.
She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism. When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.
Expert review by John Kim, Senior Product Manager, Furnaces
Furnaces heat your entire home by burning a fuel source to produce heat, warming cool air from your home with that heat and redistributing it through your home via ductwork.
According to the United States Census Bureau, gas furnaces are the most common heating appliances in the country, especially in northern states.
Horizontal flow in HVAC refers to the air handler or furnace airflow direction.
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