Installation manual

McQuay IM 487-4 31
Introduction
• Because drain pans in any air conditioning unit have some
moisture in them, algae, etc. will grow. Periodically clean to
prevent this buildup from plugging the drain and causing the
drain pan to overflow. Clean drain pans to prevent the spread
of disease. Cleaning should be performed by qualified
personnel
.
Figure 33. Condensate drain connection
Gas Piping
See the “Installation” section of the gas-fired furnace
installation manual, Bulletin No. IM 684 or 685.
Piping for Steam, Hot Water/ChIlled Water Coils
Factory-installed chilled water coils are installed in a coil
section that can be designed to accept a factory-installed
heating coil immediately upstream. The coil section can be
ordered in either the draw-through or blow-through position.
All chilled water piping can be done internal to the unit
without requiring a piping vestibule (except on sizes 800–802
when heating coils are included in the cooling coil section).
Steam and hot water coils can be factory installed in either a
heat section, or in the combination coil section. These sections
can be located either in the draw-through or blow-through
position. When a steam or hot water coil is installed in the heat
section, all piping can be done internal to the unit without
requiring a piping vestibule. Refer to Figure 35 and Figure 37
on page 33.
When a steam or hot water coil is installed in the combination
coil section, the coil connections project to the inside surface
of the door panel. Holes can be cut in the door panels to
connect the piping to the coils, or an accessory piping
vestibule can be added to the unit to provide piping space.
Refer to the section on vestibule assembly instructions. The
piping can then be routed back within the unit as shown in
Figure 35 on page 32.
To avoid piping penetrations through the roof external to the
curb, holes can be cut through the floor of the unit at the
locations specified on the certified drawings.
WARNING
Drain pans must be cleaned periodically. Material in
uncleaned drain pans can cause disease.
Cleaning should be performed by qualified personnel.
S t a t i c P r e s s u r e " P "
( i n . w . o . )
D r a i n P a n
4 " ( 1 0 2 m m )
M i n i m u m
" A "
8 " ( 2 0 3 m m )
M i n . o r 2 x " P "
M i n i m i z e T h i s
D i m e n s i o n
V i e w A
N o t e : D r a i n l i n e m u s t
n o t b e r u n h i g h e r
t h a n t h i s l e v e l
C o p p e r T u b e
( o n e e a c h e n d o f c o i l )
S e e V i e w " A "
CAUTION
Seal all holes in the unit floor to prevent water leakage into the
building.