Thermo Products AH2-A, AH1-A Recommended, Heating Capacity, Water Flow Rates, btuh, for Heating

All installations and services must be performed by qualified personnel.

	Recommended
Heating Capacity	Water Flow Rates
(btuh)	for Heating
	(GPM)
40,000	4
60,000	6
80,000	8
100,000	10

DUCT SYSTEM

The duct system and load sizing calculation should follow the design standards of Air Conditioning Contractors of America (ACCA) - manuals D & J - or the American Society of Heating, Refrigeration and Air Conditioning Engineers, Inc. (ASHRAE) Latest Edition Fundamentals Volume.

To aid you in evaluating existing duct systems quickly, review the chart on Page 11 which shows the CFM capacity for square inch areas, based on .10" wc static pressure (SP) loss on the supply systems.

Each of the system's components (trunk lines, take-offs, runs and register and grill-free areas) must be properly sized and matched together to ensure you are obtaining the air handling capacity of the duct system. A 12x8 duct with a 400 CFM capacity, for example, WILL NOT flow 400 CFM if the register(s) to which it connects can only flow a total of 200 CFM.

The air handling capacity MUST BE EQUAL TO the supply system at a minimum when sizing the return air duct system. It is recommended to follow design parameters set down by ACCA or ASHRAE on the return air duct systems.

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