GENERAL
Limitations: Ductwork must be in accordance with one of the fol-
lowing: Standards of the National Fire Protection Association for the installation of Air Conditioning and Ventilating Systems of other than Resident Type (Pamphlet 90A) or Residential Type Warm Air Heating and Air Conditioning Systems (Pamphlet 90B).
4.Installation near turns. (Refer to Figure 8). If heater must be installed closer than 4 feet from the downstream side of a turn, turning vanes must be installed in the turn. The turning vanes will straighten out the air flow so it will be uniform over the face of the heater.
Location: Chromalox Duct Heaters may be located anywhere in the duct system.
NOTE: The minimum distances shown are limitations. Wherever possible, locate as far away from these limits as practical. In any case, this distance with any required airflow correction must be sufficient to accomplish even air flow at a velocity equal to, at least, the minimum stated on the heater nameplate.
1.Installation near heat pump, central air conditioner, filters or humidifier. (Refer to Figure 5).
Duct Heater
Duct Heater Here or Here
2 Ft.
Min.
Air | Flow |
|
4 Ft.
Min.
Air
Flow
4 Ft.
Min.
Heat Pump,
Figure 8
5.Installation with duct transitions in some air distribution sys- tems, the duct heater may be considerably larger than the duct- work and the duct area must be increased by a sheet metal tran- sition. The slope of the transformation piece on the upstream side of the equipment is limited to 30° as indicated in Figure 9. On the leaving side, the slope should not be more than 45°.
Central Air Conditioner,
Filters or Humidifier
Figure 5
2.Installation near air handler discharge. (Refer to Figure 6).
Duct Heater
Air
Flow
30"
Max.
Air
Flow
30°
4 Ft. Min.
Duct Heater
45°
45°
Max.
4 Ft. Min.
4 Ft.
Min.
Air Handler
Figure 6
3.Installation in branch duct
Air | Flow |
|
4 Ft. Min. Straight Section
Duct Heater
Figure 7
Figure 9
6.Do not insulate control or terminal box. (Refer to Figure 10).
| External |
| Insulation |
Top of Duct | Duct Heater |
| Leave Control |
| Box Uninsulated |
| Figure 10 |
