FourFront Design, Inc. was asked to design a 1,000 SF, 9-story parachute drying tower. The tower is used to clean and dry the parachutes for the MAFB B-52 fleet.

The drying tower maintains a relative humidity level of 50% (summer) and 30% (winter) at all times. We had to consider the rate of water evaporating and exhaust rates required.

The design utilizes a fixed plate heat recovery system to replace humid air with dry outside air during winter months. The heat exchanger also transfers sensible heat to maximize efficiency. A hot water heating coil is incorporated to supplement the energy recovery system to maintain the tower temperature. In humid summer months, the system dehumidifies with a chilled water coil. In extremely dry conditions, a humidifier supplies moisture to maintain humidity levels.

We had to maintain a negative air pressure compared to the parachute drop-off area as the humidity would cause several problems when it would react to the cold, winter air at the doorways. Our team designed different types of energy recovery systems and designed humidifiers for the project.