呢部 compressor 可唔可以帶住 tool，並喺 duty limit 內回氣？
將 working pressure 下 delivered CFM 同 average demand 加 reserve 比較。Receiver 只會喺 cut-out 至 cut-in 之間提供短暫 burst，補唔到 sustained airflow deficit。
方法
Average demand = tool CFM × use fraction。Receiver free air 用 tank volume 同 gauge pressure 差；refill 只會喺 compressor CFM 減 concurrent average demand 為正數時計。
重要限制
工具唔會批核 pressure vessel、relief setting、pipe network、air quality、industrial continuous service 或 exact tool performance；要用 working pressure 下 delivered-air rating 同廠商 duty-cycle manual。