Installation Manual

Connecting Fresh Air Duct

The indoor ceiling cassettes have a fresh air intake port for ventilation. A booster fan and

duct (field supplied) must be used to feed outdoor air to the indoor unit.

Determine the duct diameter, length and booster fan size based on the required airflow.

See table below for duct and hole sizes:

FRESH AIR INTAKE

NOTE: Fresh air intake amount should be 20% or less of whole air amount to

prevent condensation.

Unit Size Hole Diameter

Min. Duct

(BtuH) inch (mm) Diameter

18,000 2.375 (60) 2.5 (64)

24,000-48,000 2.875 (73) 3.0 (76)

To install fresh air intake:

• Locate the fresh air hole on side of cassette unit

• Carefully remove knockout to open fresh air hole

• Cut a round hole through insulated wall

• Using a duct collar, attach fresh air duct to cassette

Fresh air hole