関連ワード:  how does a closed loop system work    how does a closed loop geothermal system work    how does a closed loop cooling system work    how does a hybrid closed loop system work    how does a closed loop water system work    how does a closed loop hydraulic system work    how does a closed loop heating system work    how does a closed loop control system work    how does open loop system work    how do chiller or closed loop systems work refrigeration