all the universal exhaust hoods in the kitchen are concentrated in large and medium-sized ventilation duct systems, and the oil fume purifier and large exhaust fan are used for the exhaust pipes. therefore, if there is a stove in the restaurant kitchen, the exhaust fan and fume purification equipment need to be turned on. in this way, the exhaust fan exhaust pipe not only has poor function but also uses a large amount of electricity. in a good hotel, the annual energy consumption of natural ventilation at home accounts for 2.8 of the total annual dose of the total dose in the home