Air - Moisture Holding Capacity vs. Temperature
Calculate the moisture holding capacity of air at different temperatures. The moisture holding capacity of air increases dramatically with increased temperature, which is critical for drying processes where air is used to transport moisture away from process and products.
Overview
The moisture holding capacity of air increases with temperature. This relationship is crucial for understanding drying processes and energy efficiency.
Key Observation
The moisture holding capacity of air at 100°F (38°C) is approximately 10 times the moisture holding capacity of air at 30°F (~0°C).
Energy Economy Consideration
It is generally good energy economy to increase the air temperature in a dryer as much as possible. The increased moisture transport capacity of air at higher temperatures outweighs the increased energy consumption for heating the dry air to higher temperature.
Reference Data
SI Units
Moisture holding capacity of air - kg water per kg dry air
Imperial Units
Moisture holding capacity of air - lb water per lb dry air
Alternatively expressed as - lb water per 1000 cubic feet dry air
Notes
- Higher temperatures significantly increase the ability of air to hold moisture
- This principle is fundamental to drying processes
- Optimal dryer temperature selection balances energy input with moisture removal efficiency