A furnace designed with the blower motor positioned beneath the heat exchanger is referred to as what type of furnace?

A furnace designed with the blower motor positioned beneath the heat exchanger is classified as a downflow furnace. In this design, air enters the furnace from the top, passes over the heat exchanger, and is then blown downward into the living space. This configuration is commonly used in applications where the furnace is located in the basement or in a crawl space because it allows for efficient heat distribution.

In contrast, an upflow furnace would have the blower positioned above the heat exchanger, pushing heated air upward into the space. A horizontal flow furnace is designed to operate with the heat exchanged horizontally, typically utilized in tight spaces where height clearance is limited. The term vertical flow typically relates to the general direction of air movement, but it's not the specific term used for this configuration.

Understanding the orientation and flow design of a furnace is crucial for proper installation and ensuring that it operates efficiently within a given space.