ANL heat pumps have been designed and constructed to satisfy small and medium-sized cooling and heating applications in residential or commercial venues. The machine is arranged for using both hydraulic circuits (evaporator and condensing unit), therefore it can be used both like a water chiller and a heat pump. The commutation between chiller and heat pump operation is obtained managing the chiller circuit. The units are characterized by their silent operation, high-efficiency performance, and reliability, thanks to the use of heat exchangers with a large exchange surface and high-efficiency silent scroll compressors.