Marv4 heat recovery outdoor units belong to MARV4 series, they have 3-pipes instead 2-pipes and they allow to cold in one thermal zone/ room and to heat at the same time in another thermal zone/room, giving to final users maximum freedom and flexibility and also energy saving compared to traditional solution or traditional heat pump units, because refrigerant will not condensate outside but inside the indoor units which have to heat. DT3-RC1/2 distribution kit has the main function in a installation with MARV4 heat recovery because it “decides” the running mode of its own indoor units. So thanks to two or more distribution kits it will be possible to cool and heat at the same time with only one system instead of two systems.