57
STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
Table 55-1:
Steam Injection troubleshooting guide (continued)
Problem
Possible cause
Action
Space humidity will not rise to
humidistat set point
(continued)
• Foreign matter is preventing valve
from opening.
• Clean or replace valve.
• Excessive outside air volume.
• Reduce air volume.
Condensate in duct
• Humidifier is mounted too close to
internal devices (dampers, turning
vanes, etc.) in duct.
• Check fan, dampers, VAV, etc.
• Move humidifier tubes to a point farther upstream from
internal devices.
• Add dispersion tubes for shorter absorption distance. consult
DriSteem to determine the total number of tubes required.
• A noninsulated duct is passing
through an unheated area (duct
surface temperature is too low).
• Insulate ductwork.
• Air cannot absorb steam quantity
being discharged.
• Humidifier is operating when blower is off. Install airflow
proving switch.
• Valve is hunting. See previous page for instructions.
• Air temperature in duct is too low for steam quantity being
supplied.
• Air cfm in duct is too low for steam quantity being supplied.
• Steam pressure is too high, causing
excess capacity.
• Reduce steam pressure.
Humidifier is noisy
• Tube silencer is missing.
• Install silencer.
Note: Unless special-ordered, silencers are furnished only with
Model 60 and Model 70 tubes equal to or shorter than
48” (1219 mm), and only with black iron piping.
• Dispersion tube output is excessively
high.
• Install additional tubes.
Troubleshooting
TROUBLESHOOTING
