Which type of furnace is most suitable for installation in an attic space?

The most suitable type of furnace for installation in an attic space is the horizontal furnace. This design is advantageous in settings with limited height, such as attics, because it can be installed in a space with lower clearance while still providing efficient heating.

Horizontal furnaces also facilitate ductwork installation and airflow management more effectively in tight attic spaces. They are often installed in such a way that their layout complements the structure of the roof, allowing for effective use of the attic space without impeding accessibility for maintenance.

While other types of furnaces such as vertical and downflow are designed for different setups and might not fit well in the typically confined space of an attic, a horizontal furnace's design optimally addresses the requirements and challenges of that installation environment.