RNW 411 dehumidifier is used to control room relative humidity in radiant underfloor, ceiling and wall cooling systems. It is a complete refrigeration unit, condensed with water and equipped with pre-condenser coils and water-to-gas heat exchanger, which are fed by one hydronic connection to the water coming from the radiant panels. It has a zinc-plated sheet metal casing, and it is horizontally installed into false ceilings. It includes a 3 speed direct coupled centrifugal ventilation fan and a connection box for power supply with PCB. This is a very compact unit, which is particularly noiseless and therefore suitable for residential applications.