Duct sizing

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DHM090 & DHM120

Use minimum 10” diameter for duct lengths up to 25’ or minimum 12” round for lengths longer than 25’. Duct branches from the main inlet/exhaust should be minimum 10” round for 2-3 branches, and 12” round or larger for 4 branches or more.

For the optional fresh air ventilator port, use 6” round, insulated duct for lengths up to 50’.

Use 8” round duct for more than 50’ if more than 100 CFM is required.

DHM065

Use minimum 8” diameter round for duct lengths up to 25’ or minimum 10” round for lengths longer than 25’. Duct branches from the main inlet/ exhaust should be minimum 8” round for 2-3 branches, and 8” round or larger for 4 branches or more.

Isolated areas:

Effective dehumidification may require ducting to isolated or stagnant air flow areas

The DHM090 and DHM120 models have a 6" port that gets ducted to an EARD6TZ vent damper and to a vent hood outside the home. If ventilation is not used, make sure to cap off the vent port.