HDG Series Air Handler | INSTALLATION INSTRUCTIONS | Heat Controller, Inc. |
7.0 DUCTWORK
Field ductwork must comply with the National Fire Protection Association NFPA 90A, NFPA 90B and any applicable local ordinance.
Warning
Do not, under any circumstances, connect return ductwork to any other heat producing device such as fireplace insert, stove, etc. Unauthorized use of such devices may result in fire, carbon monoxide poisoning, explosion, personal injury or property damage.
Sheet metal ductwork run in unconditioned spaces must be insulated and covered with a vapor barrier. Fi- brous ductwork may be used if constructed and installed in accordance with SMACNA Construction Stan- dard on Fibrous Glass Ducts. Ductwork must comply with National Fire Protection Association as tested by U/L Standard 181 for Class I Air Ducts. Check local codes for requirements on ductwork and insulation.
•Duct system must be designed within the range of external static pressure the unit is designed to operate against. It is important that the system airflow be adequate. Make sure supply and return ductwork, grills, special filters, accessories, etc. are accounted for in total resistance. See airflow performance tables in this manual.
•Design the duct system in accordance with “ACCA” Manual “D” Design for Residential Winter and Summer Air Conditioning and Equipment Selection. Latest editions are available from: “ACCA” Air Conditioning Contractors of America, 1513 16th Street, N.W., Washington, D.C. 20036. If duct system incorporates flexible air duct, be sure pressure drop Information (straight length plus all turns) shown in “ACCA” Manual “D” is accounted for in system.
•Supply plenum is attached to the 3/4” duct flanges supplied with the unit. Attach flanges around the blower outlet.
IMPORTANT: If an elbow is included in the plenum close to the unit, it must not be smaller than the dimensions of the supply duct flange on the unit.
•IMPORTANT: The front flange on the return duct if connected to the blower casing must not be screwed into the area where the power wiring is located. Drills or sharp screw points can damage insulation on wires located inside unit.
•Secure the supply and return ductwork to the unit flanges, using proper fasteners for the type of duct used and tape the
17
