According to standard GB/T 1236-2000 and AMCA210-99, fan performance is tested in the vent-chamber under the two conditions that fan outlet is connected to the short duct and directly connected to the chamber, the pressures are obvious different.

• 根据GB/T1236-2000及AMCA210-99标准,对风机出口联接短风管和直接联接风室两种情况分别在排气风室中对风机性能进行测试,压力产生明显差异。