Thermo Products 125n, chx-3 75n, 100n operation manual A

All installations and services must be performed by qualified service personnel.

DUCT SIZES FOR HOMES, QUIET OFFICES, OR SIMILAR INSTALLATIONS

TABLE 2A

Each of the system components (trunk lines, take offs, runs and register and grill-free areas) must be properly sized and matched together to ensure the necessary air handling capacity of a duct system. A 12" x 8" duct with a 400 CFM capacity for example will not flow 400 CFM if the register(s) to which it connects only flow a total of 200 CFM.

The speed of the blower motor may have to be changed to obtain the proper 55°F to 85°F temperature rise for heating when an air conditioning coil is installed. This depends on the static resistance of an individual duct system and the size of the air conditioner.

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