limit value of fume emission concentration, fume emission height.

1. limit value of fume emission concentration: according to the type and regional division of specific catering industry, the limit value of fume emission concentration in different emission areas is specified. For example, in the downtown area, the limit is low, while in the general area, the limit is relatively high.

2. Oil fume discharge height: The height of the oil fume discharge port should meet certain requirements, so as to improve the effective height of oil fume discharge and reduce the impact on the surrounding environment.