Nortec NH Series - Manual (Page 50)

47 | Start Up
Selecting an RH Setpoint
The optimum humidity setpoint depends on the reasons that a conditioned environment is
being humidified. The “ASHRAE Handbook – HVAC Applications” recommends specific design
relative humidities for specific applications. Also see NORTEC publication “When You Need
Humidity” (Form 124A) for more information on humidity settings.
Health and Comfort - The benefit of humidity is most pronounced for health and comfort in the
40-60% range. A humidity setting of 40-50 % is recommended for this purpose to prevent over
humidifying.
Temperature Setback - In cold climates it is often necessary to reduce the humidity level in a
conditioned environment to prevent build-up of condensation on the inside of exterior walls,
windows, and trim. It is highly recommended that the temperature setback function of the
NORTEC digital controls be used under these conditions to prevent damage from condensation.
The digital control with an outdoor temperature sensor installed will automatically setback the
humidity setpoint to correspond with outdoor temperature.
Duct High Limit – The duct high limit is intended to prevent saturation and wetting in duct work
at high load conditions. NORTEC recommends a setting of 85% for the duct high limit. It may
be necessary to reduce this setting if the duct work is very cold or in contact with exterior cold
surfaces.
Note: The job site design may have specified a setpoint chosen specifically for the site.
Refer to site documentation and where possible use setpoints specifically determined
for the site.