These types of dehumidifiers utilize thermo-electric / Peltier technology.  An electric current is passed through two dissimilar metals which transfer heat, and this causes the same effect that is used by compression technology.  The one benefit to this technology is that there are no moving parts so the only noise that is emitted from these units is produced by the fan that circulates the air.  Although less energy efficient than compressor dehumidifiers, they are effective for smaller areas and offer almost silent operation.

Description: This 11.8 oz. Mini Dehumidifier uses Peltier (Thermo-Electric) Technology to provide energy efficient, whisper quiet and vibration-free operation. The compact size is ideal for removing excess moisture in places such as nurseries, small bedroom, closets, wardrobes & more. Automatically switch off with warning indicator light when water tank is full. more>

Description: This 11.8 oz. Mini Dehumidifier uses Peltier (Thermo-Electric) Technology and UV/Tion Filters to provide energy efficient, whisper quiet and vibration-free operation. The compact size is ideal for removing excess moisture and purifying the air in places such as nurseries, small bedroom, closets, wardrobes & more. Automatically switch off with warning indicator light when water tank is full. more>