What is the significance of the 'practical range' in humidification processes?

• A. The temperature range from cool liquid to low-pressure steam used in humidification.
• B. The range of moisture capacity of the air.
• C. The humidity range accepted by occupants.
• D. The outdoor temperature range.

Answer: (B)

The practical range shows how much moisture the air can hold under the operating conditions—the moisture capacity or humidity ratio range available to the humidification system. Since warmer air can carry more water vapor, this range sets the upper and lower limits of humidity that can be added without causing problems. Staying within this range ensures you can reach the desired space humidity without driving condensation on cold surfaces, mold growth, or excessive energy use, and it helps in selecting and controlling the humidifier.