Greenheck Duct Heaters Series IDHB and IDHC (478052) - Manual (Page 4)

Insulated Duct Installations
Duct with External Insulation
The external insulation is to be removed from
the area where the heater is mounted.
Note: Size of heater is based on the duct size
(no recess required).
Duct with Internal Insulation
S-type with internal insulation left in place or duct constructed from insulation board
Recess = Insulation Thickness
Note: Size of heater is based on the following:
Heater ‘H’ = Duct ‘H’ - (Insulation Thickness x 2)
Heater ’W’ = Duct ‘W’ - Insulation Thickness
(recess required)
Internal insulation cut away
The internal insulation is to be removed from the
area where the heater is mounted
Recess = Insulation Thickness
Note: Size of heater is based on the duct size
(recess required).
4