The no-duct inductive ventilation system originate from the duct spray nozzle inductive ventilation and air conditioning system, which was advanced by Swedish ABB Company in 1974 and named as DIRVENT SYSTEM.

• 无风管诱导通风系统起源于瑞典ABB公司1974年发明的风管型喷嘴诱导通风和空调系统(DIRVEN7 SYSTEM)。