The main activity in the commercial kitchen is the cooking process, which will produce heat and waste gas. These heat and waste gas must be captured and then discharged into the kitchen space to control the odor comfort and thermal comfort of the kitchen. In the waste gas generated and discharged from the kitchen, in addition to oil fume, a large part of it is peculiar smell. Therefore, many kitchen exhaust systems will need to add odor purification schemes To meet IAQ requirements. Working principle of elwalker photolysis and oxidation 
 use ultraviolet light beam and ozone to photolysis and oxidation of oil fume molecules to convert them into carbon dioxide and water, so as to control kitchen oil fume and odor. Photolysis: UV-C ultraviolet C-band (254nm) beam irradiates oil fume gas, changes the molecular structure of small oil particles, and degrades high molecular compounds into low molecular compounds. Ozone acts on UV-C ultraviolet C-band (185nm) the light beam decomposes the oxygen molecules in the air to produce free oxygen. The combination of free oxygen and oxygen molecules produces ozone. Ozone is a strong oxidant, which oxidizes and decomposes the alcohols, aldehydes, benzene and other molecules in the odor into harmless compounds such as water vapor and carbon dioxide, so as to control the role of kitchen oil fume and odor, and greatly reduce the odor in the flue.