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Sizing mini-split head for airflow

jwasilko | Posted in General Questions on

We’ve got a 1280sf (32×40) room above a garage, currently heated by a gas forced-air furnace and AC. The room is completely open (no dividing walls).

We’d like to add a heat pump to take care of the primary heating/cooling and keep the gas furnace/AC as backup.

I will do a Manual-J for the space, but I’m curious how do ensure that I have sufficient airflow? Can a single mini-split head cover that much space, or will we be forced to use multiple heads?


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  1. kyle_r | | #1

    It depends on how well insulated and air tight the room is. I use a single head to heat my open concept 1200 sqft main floor with no issues.

    1. jwasilko | | #2

      Thanks. It's relatively recent construction and we recently added more blown-in fiberglass to the attic area.

      Good to know a single head can take care of that floor space.

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