All installations and services must be performed by qualified service personnel.
The vent connector pipe between the furnace and chimney shall be of equal diameter as the flue outlet of the furnace. The vent connector pipe must be made of 24 gauge (or thicker) corrosion-resistant steel. The vent connector pipe should be as short as possible and installed so that it has a continuous rise from the furnace to the chimney. The horizontal length of a connector to a natural draft chimney or vent serving a single appliance shall not be more than 75 percent of the height of the vertical portion of the chimney or vent above the connector. Elbows should be minimized and the pipe should be joined with metal screws and supported by straps. All horizontal runs of vent connector pipe should be pitched upward a minimum of 1/4 inch per foot of run. A thimble should be used to connect the vent connector pipe to the chimney so the pipe may be readily removed in case of inspection or replacement. See Fig. 6 on preceeding page.
C. DUCT WORK:
The duct system should follow the design standards of Air Conditioning Contractors of America (ACCA) or ASHRAE. The duct system should be sized for the maximum airflow capabilities of the furnace being installed.
DUCT SIZES FOR HOMES, QUIET OFFICES OR SIMILAR INSTALLATIONS
VELOCITY APPROXIMATELY 800 FEET PER MINUTE
All trunk lines, take-offs, registers and grill free areas must be figured when determining the air handling capacity of a duct system. By utilizing the previous chart, one can obtain the necessary duct system size. (For example, see Fig. 7). Use a supplier's catalog for proper sizing of outlet and return air registers to insure that the register will meet the airflow requirements of the run to which it is connected.
