While many facility managers and maintenance personnel focus on temperature, humidity levels play just as significant a role in building comfort. When the relative humidity exceeds 60 percent, it makes the air feel damp and sticky. The moisture can also promote the growth of mold and mildew, which can slowly destroy the building and its contents and even cause health issues such as allergic reactions and respiratory ailments.
What Causes High Humidity Levels in Commercial Buildings?
Excessively damp air is present in many areas of the United States. Approximately half of the nation’s population experiences a “moist” climate and 25 percent live and work in a “humid” climate zone. Other contributing causes of moisture inside a commercial facility include water that leaks through the building envelope (the physical barriers that separate the conditioned and unconditioned environment), leaks from the plumbing system, moisture retained in construction materials, and damp ground underneath the structure.
The Importance of Humidity Control in Commercial Buildings
Generally, a relative humidity level of 20 to 60 percent is optimal in most commercial facilities. Keeping the humidity within this range will maximize occupant comfort and prevent excessive moisture in the air that can foster mold growth. Implementing efficient building humidity control measures is essential for removing moisture and creating a drier indoor climate.
HVAC and Humidity Control in Buildings
The building’s HVAC system plays a vital role in ensuring the appropriate humidity levels. During the cooling phase, dehumidification occurs when air passes over cooling coils maintained at a temperature below the air stream. When the air stream condenses on the coil, it will result in the removal of moisture. The use of specialized HVAC equipment such as desiccant dehumidification, chilled water and direct expansion cooling units can provide additional moisture control in extremely humid environments.
Factors That Impact Humidity Control
When planning new construction or renovation projects, a careful design of the facility and its building humidity control systems can help prevent moisture and ensure the comfort of the occupants. The project’s engineers should work closely with the facility manager to assess the ideal indoor climate, which helps to determine the size and type of the HVAC equipment required for the facility.
When diagnosing existing structures that are experiencing moisture and humidity issues, an inspection of the building envelope is usually the best place to start. Typical signs to look for include leaks in the roof, condensation on windows, and holes or cracks around piping or conduits that can allow moist exterior air to infiltrate the envelope.
An assessment of the HVAC system is also beneficial. Conducting a comprehensive cooling load calculation will provide critical information regarding system performance factors that influence humidity levels, such as the optimal airflow and the chilled water flow rate.
Reynolds Can Provide Cost-Effective Building Humidity Control Solutions for Your Commercial Building
As a leading building solutions company, Reynolds offers expert commissioning and engineering services that will prevent or address humidity problems and help you avoid the costs associated with moisture issues. Contact us to learn more today.