Specifically, consumers can consider the following aspects when purchasing a range hood: 1 exhaust air volume. This is one of the main quality indicators of range hoods. The exhaust air is large, and the generated soot gas does not overflow outside the cover. Most of the soot gas is sucked into the hood and discharged to the outside through the exhaust duct. But the amount of exhaust air is not as big as possible. If the exhaust air volume is too large, it will take away too much heat, which will affect the normal heating of the gas stove fuel. 2. Exhaust efficiency. Exhaust efficiency refers to the percentage of the amount of fouling that is removed from the hood and the amount of smog that is produced during cooking. China uses the determination of the content of carbon monoxide. According to regulations, the exhaust efficiency should be greater than 60%. Tips: The above two items can be read at the time of purchase. If the instructions are not indicated, it is best to choose another one. 3 noise. Noise is also an important indicator of the performance of range hoods. In foreign countries, the noise of the range hood is controlled at 30 dB-50 dB. In China, most range hoods use multi-blade centrifugal fans, which have relatively high speed and loud noise. Therefore, China's relevant standards stipulate that the noise can not be greater than 70 decibels. When consumers are shopping, they can turn on the audition to judge the noise level. 4 oil filter device. After the range hood has been used for a period of time, the suction surface will be blocked by oil and sometimes it will drip off the oil. Therefore, oil filtering devices are generally provided. There are several types of oil filtering devices: they are made of single-layer or double-layer wire mesh. They can be removed and cleaned regularly before being installed in the suction port. The labyrinth filter screen can be used to filter the soot by collision principle. It can be removed periodically for cleaning. After the oil is removed, it flows into the oil cup along the oil sump and can be poured out periodically. Liu Lele Shi Yafeng Ultra-Thin Ball Valve,Industrial Ultra-Thin Ball Valve,Thread Globe Valves,Threaded Swing Check Valve ZHITONG PIPE VALVE TECHNOLOGY CO.,LTD , https://www.ztpipevalve.com