The biggest residential furnace is something like 135000 BTU, which is sufficient to heat a house upto 6500 Sq Ft (incl. basement). So many houses starting at 6000 Sq Ft (incl. basement) would consider using two units.
jeffrey815(Smartiecat)
One for second floor and one for first floor/basement. It is also very energy efficient since you can turn down the one for first floor/basement at night.
(#11294113@0) Last Updated: 2018-1-16 This post has been archived. It cannot be replied.