Mixing Box is a new hydraulic substation consisting of a series of hydraulic modules that mix and relaunch the heat transfer fluid towards the emitters including: underfloor radiant systems, dehumidification units, air treatment units such as UC, hydronic batteries after treatment. The hydraulic modules are placed in an outdoor painted steel cabinet or recessed including hydraulic separator with automatic vent, electrical panel for the necessary wiring, thermal insulation and anti-condensation. They also include A/R thermometers, high efficiency circulators, thermostatic mixing valves (heating only) or with 0-10V control for systems in hot or hot/cold only.