Why Mini Splits Work Well for Garages

Detached garages can't connect to your home's central ductwork. A mini split solves this with a single outdoor unit and one wall-mounted indoor unit — no ductwork required. Installation typically takes one day.

Sizing a Garage Mini Split

A rough rule: 1 ton (12,000 BTU) of capacity per 400–500 square feet of garage space, adjusted for insulation quality and ceiling height. A typical two-car Chicago garage (400–500 sq ft) usually needs a 9,000 to 12,000 BTU system.

If the garage is poorly insulated or has high ceilings, size up. Undersizing is the most common mistake — the system will run constantly and struggle to maintain temperature on cold days.

Cold-Climate Performance

Standard mini splits lose efficiency below 20°F. For Chicago winters, choose a cold-climate mini split rated to operate at -13°F or lower. These systems maintain full heating capacity down to 5°F and partial capacity below that.

What to Expect from Installation

The outdoor unit mounts on a pad or wall bracket near the garage. The indoor unit mounts high on an interior wall. A small conduit runs through the wall connecting them. Most installations are complete in 4–6 hours.

Cost Range

A single-zone mini split for a garage typically costs $3,000–$6,000 installed, depending on system size and installation complexity. Cold-climate models cost more than standard models.