Refrigerant flowing through each air conditioning unit of a multiple air conditioning system is respectively detected by a refrigerant flow sensor provided in each air conditioning unit and the degree of opening of a refrigerant flow control valve arranged in each air conditioning unit is controlled...http://www.google.com/patents/US5142877?utm_source=gb-gplus-sharePatent US5142877 - Multiple type air conditioning system which distributes appropriate amount of refrigerant to a plurality of air conditioning units
