9
SUPPLY AND RETURN DUCT REQUIREMENTS
All duct work must adhere strictly to all local and national code
requirements. It is critical that the return air duct has the same free area as
the opening provided on the fan coil unit. If there is no ducted return,
installation codes may limit the unit to installation only in a single story
residence. Ducting should normally be sized for external static pressures
of 0.15 to 0.3 inches H
2
O total.
Figure 1
Figure 2
Figure 1: Correct way to duct plenum off of air handler whenever possible
in a new installation.
Figure 2: Incorrect way to duct plenum off of air handler.
