Hi Sirs
One 150m2 villa need air conditioning all the year. There're VRV system and normal heat pump +FCU (heating and cooling) can be used for it. The initial cost VRV is at least 50% higher than normal air cooled hp but it's no problem with freezing issue in winter.
If I select to use normal hp ,what is the best way to protect water pipe not freezing in winter season?

Thanks for your input.

best regards
LC