Abstract: A system (200) for dehumidifying air, comprising: at least one local dehumidifying unit (210), comprising: o a main air channel (213) including a primary air channel section (214), a secondary air channel section (216), and a tertiary air channel section (218); ?an air pump (228) that is arranged inside the main air channel (213) and configured to effect a flow of greenhouse air therethrough; ?a main water channel (231); ?a heat exchanger (212) in which said primary and tertiary air channel sections (214, 218) are arranged in heat exchanging contact; and •a common water supply unit (240) configured to provide for a flow of cooling-water to the at least one local dehumidifier (210).

Abstract: The invention relates to a free piston type compressor 10 according to the invention comprises a first free piston 2a and a second free piston 2b interconnected by a torsion body 3a and 3b, and elastic bending element 4a and 4b to the central electromotor 5. In accordance with the invention the driving force is applied transversely to the direction of the expected displacement D of the first free piston and the second free piston.