if there is no reserved oil fume pipe, it must be discharged. The impact on the surrounding area should be considered when discharging outside. First, it must be approved by the local environmental protection bureau. Simply, it can be discharged outside. If the local environment is very strict, it is necessary to make a pipeline directly to the top of the building, which has to contact the property to see where the pipeline is laid. Also, if it is in a shopping mall or supermarket, the shopping mall should consider this issue and contact the property management of the shopping mall directly, without even going to the Environmental Protection Bureau. It's cheaper to buy food yourself, and it's easier to deliver it, which needs to be analyzed through cost and manpower before making a decision.