The unit includes both dehumidification and humidification to maintain air within the "comfort zone".

Dehumidification

Air is dehumidified to prevent health issues and equipment damage. When warm, humid air is cooled, its relative humidity increases. If it reaches 100% saturation, moisture condenses. In an A-C unit, air is cooled below the target temperature (e.g., to 10°C) to make it supersaturated, causing excess moisture to precipitate out. This dry, cool air is then reheated to the desired temperature (e.g., 20°C). At this new temperature, the air's relative humidity will be at a comfortable level, typically around 50%. Without this process, inhaling highly humid, cold air could lead to respiratory issues. Additionally, moisture condensation on electronic equipment can cause damage.

Humidification

Humidification is necessary when the incoming air is too dry. Dry air can cause discomfort, skin irritation, and static electricity issues. The humidifier adds moisture back into the air, usually by spraying a fine mist of water, to raise the humidity to the desired level and bring the conditions back into the comfort zone.

The chart provides the following useful information:

• Dry Bulb Temperature: The actual air temperature, measured with a standard thermometer.
• Wet Bulb Temperature: The temperature of air measured with a thermometer covered by a water-soaked cloth, indicating evaporative cooling potential.
• Dew Point Temperature: The temperature at which air becomes saturated and condensation begins.
• Relative Humidity: The percentage of moisture in the air compared to the maximum moisture the air can hold at that temperature.
• Moisture Content: The amount of water vapor present in the air, expressed as a ratio (e.g., grams of moisture per kilogram of dry air).