Which way is good for heat pump deforsting?

Heat pumps are always placed on balcony of top roof, which will lead frosting in winter and effect the daily using of consumers.

Natural Defrosting: Keeping working for a while, then stop, and the heat from compressor will defrost, but it will take a long time.

Hot Gas Defrosing: Compressor will exhaust, and hot air will defrost.

Electric Assist Defrosting: Common factories will supply this kind of defrosing. When defrosting, stop compressor, fan and magnetic valve, system will automatically defrosing, open valve after finishment, system will start to
work.

In summary, electric assist is the best way, however if your heat pump is very easily frosting.