By Anne Fonda
A horizontal flow furnace is a type of forced-air heating system that blows heated air into the home through ductwork in a horizontal fashion. The furnace is engineered to be installed in a horizontal configuration and draws in air from one end and pushes heated air out the other end.
Horizontal furnace installation is necessary in homes without a basement or other area where a vertical configuration (either upflow or downflow) won’t fit due to height restrictions.
Horizontal furnaces are commonly installed in attics, crawlspaces, and basements with low ceilings. When installed horizontally, the furnace must be supported at both ends and the middle. It must also be elevated at least six inches from the floor to allow clearance for the condensate drain line to exit the cabinet in a horizontal position.
Maybe. If your current furnace is old and giving you problems, it’s time to think about furnace replacement. If your furnace is installed in a horizontal configuration in your attic or crawlspace due to height restrictions, you will need to replace it with another horizontal flow furnace.
Many Trane furnaces are available for horizontal installation. Work with your local Trane HVAC pro to find a new furnace that fits your space requirements and your heating needs.
Anne Fonda, Content Writer
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 Amy Gulas, Product Manager, Furnaces
Annual Fuel Utilization Efficiency (AFUE) measures how efficiently a furnace converts fuel to energy. The higher the AFUE rating, the more efficient the furnace.
Furnaces are a whole-home heating solution that work by burning a fuel source, like natural gas or propane, to make heat. The heat produced is combined with cold air from your home, then is re-distributed via ductwork to increase indoor temperature.
In an upflow furnace, the unit pulls in air at the bottom of the unit, passes it over the heat exchanger, and blows the heated air up and out through the top of the unit.
A downflow furnace takes in cool air at the top and heats the air over a heat exchanger. Then, it releases warm air down at the bottom.
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