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Humidity Control: Maintenance is the Key

Humidification systems are becoming increasingly popular in both the home and workplace, providing numerous health, comfort, productivity, and energy-saving benefits. In some environments such as healthcare facilities, data centers, laboratories, R&D, compound pharmacies, etc., proper humidity control is an absolute necessity.

There is a very common misconception among users, however, that humidification systems are somewhat elementary and require little maintenance. In truth, they require expert selection, design, and installation, followed by regular, meticulous preventive maintenance, to ensure optimal performance and efficiency. Manufacturer maintenance requirements can vary depending on system type and application, and it’s important that these standards are closely followed.


Supply water quality, treatment, and filtration are key to operating a clean, efficient system, whether it derives humidity from steam or cold water. Minerals in untreated water can clog heat exchangers, nozzles, and wetted pads in isothermal (steam) systems, and adiabatic (unheated) systems emit these impurities into the air. These impurities settle on surfaces and processes and can cause health problems when inhaled. Using deionized (DI) or reverse-osmosis (RO) filtered water will virtually eliminate these issues. Water should be monitored and tested regularly for quality, and standard PM practices should include inspection of filters, membranes, and TDS to keep critical supply water up to humidification system standards.


Instrumentation and controls must be checked and calibrated on a regular basis. This includes verifying that humidity and temperature sensors are reading accurately, checking control valve operation from 0-100%, and ensuring high-limit humidistats are set and operating properly. MSC recommends high limits be hardwired as opposed to controlled via a software point. Building personnel should ensure that the humidification system is operating within design parameters. For example, if a system designed to maintain 35% +/- 5% relative humidity is operating at 50% RH, the absorption distance can be affected, resulting in condensation in ductwork and wet diffusers.


MSC is expert in design, installation, maintenance, troubleshooting and repair of all types of humidification systems including boiler steam, clean steam, canister steam, centrifugal, ultrasonic, atomized, and more. For more information, contact us at (973) 884-5000.