... shaking when ventilated8. No corrosive---not corrosive the aluminum pipe and metal parts9. Durability---not decay, mildew10. Fire---resistance11. ... area(such as school, supermarket, office, stadium, theater, factory…),high requirement of the environment area, such as hospital, laboratory ... -30 degree to + 200degreeAir Velocity: 28m/sWorking Pressure: 250mmAq air conditioning non-insulated duct