18
STS INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
INSTALLATION
Piping:
The drain line piped from the humidifi er must be run to an approved sanitary
waste or suitable drain. If nonmetallic pipe or steam hose is used, it must be
rated for 212 °F (100 °C) minimum continuous operating temperature.
Minimum drain pipe sizes:
STS models 25 through 100: 3/4" (DN20) outside diameter.
STS models 200 through 800: 1" (DN25) outside diameter.
If the length of the drain piping exceeds 10' (3 m), increase the pipe size.
If combining multiple drain lines, ensure that proper common pipe sizing
practices are used.
Do not locate the humidifi er directly above a fl oor drain — skim and drain
water dumped into the fl oor drain will cause fl ash steam. This steam will rise
and saturate electrical components, adversely affecting component life and
performance.
TEMPERING DRAIN WATER
Governing codes may require that the 212 °F (100 °C) drain and skim water
from the humidifi er be tempered before it is discharged into the building drain
piping. The Drane-kooler
®
option will temper 6 gpm (22.7 L/m) of 212 °F
(100 °C) water to 140 °F (60 °C).
WATER SEAL
To allow normal operation and prevent steam from escaping through the drain
line, the installer must provide a water seal of a suffi cient height to contain the
pressure developed in the humidifi er system.
See Table 27-1 for water seal
heights.
Drain piping after the water seal must be pitched a minimum of 1/8"/ft (1%)
toward the drain. Governing codes may require more pitch.
CONDENSATE PUMP
If the proximity of a drain requires the humidifi er drain and skim water to be
lifted by a pump, DriSteem offers a condensate pump option. A check valve
is required on the discharge of the pump. Electrical power for the pump is
independent of the humidifi er. Plug the pump into a wall outlet; an integral fl oat
switch turns the pump on and off.
See the detailed piping drawings on Pages 22
through 25.
Drain
ALTERNATE WATER SEAL AND DRAIN VALVE PIPING
