... light, 3.6V/1W Absorption Cooling AdvantagesCompressor DisadvantagesSILENT, no moving partsdoes not disturb guest sleep.Noise, from ... with age. Disturbs sleep and causes guest complaints.NO VIBRATION.Vibrates from piston movement, canNot be attached ... superior absorption new technology, cooling by ammonia, no compressor, no fan, no moving part, no vibration, noiseless, maintenance-free operation. And ...