1.Power of motor matched with ventilator is defined as the shaft power with safety factor multiplied instead of the power with air outlet fully opened. To avoid overloading of motor, air outlet is not allowed to be fully opened.2.Impact is not allowed during shipping and handling, and placing the ventilator under wet and corrosive circumstances is not allowed.3.Transmission medium should be air or gas without corrosion. The medium should has a temperature less than 60„ƒat the entrance, dust rate and other solid content less than 100g/M3, and noviscousor fibersubstanceshould be contained.4.This ventilator has a one year warranty. Under normal use, problems that caused by quality of manufacturing or components are guaranteed to be fix free of charge.5.Below cases are not included in the free services:i.Problems that caused in disassembling, modification or repairing by non-qualifiedelectricianii.Problems that caused byforcemajeurelikenatural disasters orincorrectoperationiii.Problems that caused by long-time use underadversecircumstances