Greenheck MSX (470658) - Manual (Page 14)

14 Modular Supply Make-Up Air Unit
®
8. Install the Drain Line. Connect an unobstructed
drain line to the drain pan. A trap should be used to
prevent sewer gas from being drawn into the unit.
6 in. min.
6 in. min.
Drain Trap
IMPORTANT
All traps must be installed below the roof line or be
otherwise protected from freezing.
NOTE
Failure to obtain a high vacuum indicates a great
deal of moisture or a small leak. Break the vacuum
with a charge of dry nitrogen or other suitable gas
and recheck for leaks. If no leaks are found, continue
vacuuming the coil until the desired vacuum is
reached.