You pay for the electricity, which is based on V*I. It doesn't consider the power factor. But when your air conditioner is working, the power it deliver can, is based on power factor U*T*Power factor.
If you have a very low power factor, you are not getting the exact power that you have paid. For most case, power facor is from 0.85 to 0.99.
本來想買power angel, 但是其實細看規格, 我發現power angel最多只能量到總功率18XX, 但是樓主分享的這台有到37XX而且又能量到220v, 當下立斷, 還是買樓主分享的這台好了, 220v 才能量冷氣嘛,

所以就殺到光華去買了一台, 回來就到處找東西來量, 想說我的主機用的是active PFC應該很省電吧, 一量, PF0.6


PS. power angel的誤差是2%, 但樓主這台是標準0.2%, 最大2%, 不知道power angel楆的是最大嗎? 其實看人啦, 兩台價位還是不大一樣地, 看有沒有必要為了誤差和最大測量功率去多花點錢而已囉