Sunroom Comfort in Georgia: When a Mini-Split Beats Extending Ducts

Sunrooms are a sizing problem, not a ductwork problem

A glass-walled sunroom has 3–5× the cooling load of a conventional room the same size. The west wall in July is essentially a heater. Extending your existing AC ductwork into that room overloads the main system: the sunroom never quite gets cool, and the rest of the house gets too cold.

Why ductless mini-splits win for sunrooms

• Right-sized to the room. A 9,000 BTU or 12,000 BTU head can match the sunroom's actual load without forcing the main system to compensate.
• Variable-speed by default. Mini-splits modulate down on cool mornings and ramp up on hot afternoons — perfect for a sunroom that swings wildly.
• Independent control. A separate thermostat means the sunroom can stay 72 °F while the rest of the house stays at 74 °F without rebalancing the whole system.
• Heat in shoulder seasons. Our Mitsubishi and Trane mini-splits heat efficiently down to about 25 °F — covering the late October through April sunroom-use window perfectly.

When extending the main system DOES make sense

If the sunroom is fully insulated (R-30 walls, R-49 ceiling, double-pane low-E glass) and the existing AC has 1.5+ tons of headroom (rare in Metro Atlanta), extending the ducts can work. We'll size the load and tell you honestly.

See ductless mini-splits →