Air Handling Units (AHUs)

Air Handling Units (AHUs) are critical components in Heating, Ventilation, and Air Conditioning (HVAC) systems, particularly in environments where precise control of air quality and temperature is essential, such as in the pharmaceutical industry. The use of hot water in AHUs serves several purposes to maintain the required environmental conditions for pharmaceutical manufacturing and storage.

Functions of hot water in AHUs

• Heating:
  Temperature Control: Hot water is circulated through heating coils within the AHU to raise the temperature of the air being supplied to the conditioned space. This is essential for maintaining optimal temperatures in production areas, laboratories, and storage facilities.
  Winter Operations: During colder months, hot water heating is crucial to prevent temperatures from dropping below the required levels, ensuring a stable environment for sensitive pharmaceutical processes and materials.
• Humidity Control:
  Humidification: In addition to heating, hot water can be used indirectly for humidification. By increasing the air temperature, the air’s capacity to hold moisture increases, allowing for better control of relative humidity levels.
  Moisture Balance: Maintaining appropriate humidity levels is vital to prevent product degradation, ensure the proper functioning of equipment, and maintain comfortable working conditions for personnel.

Some common issues that plants face across while using incorrectly sized or Direct Steam based Hot water systems are

• Hot Water Temperatures variations (+/-5°C from the set value)
• Difficulty reaching desired temperatures
• Water hammering in the PHE, causing PHE Failures