Heat pump type LG Therma V Hydrosplit 12kW 3F 400V Hydrosplit IWT (integrated 200l tank) R32 refrigerant. HYDROSPLIT heat pumps are divided into two main DHW units: indoor and outdoor + domestic hot water tank (IWT). The outdoor unit (HU), as the name suggests, is mounted outside, while the indoor unit (HN), together with the tank, is mounted inside the building. The outdoor unit (unit), which has the entire cooling system, is responsible for extracting energy from the environment, while the indoor unit (hydrobox) transfers the extracted heat to the heating system by means of a hydraulic and electrical system. The two parts are connected by water pipes. The optimal length of the installation is in the range of 3 ∼ 10m - this allows to maintain the nominal efficiency of the unit, eliminates the possible noise of water flow to the hydrobox and has a positive effect on the correctness of operation.