It depends on the venue. If it is convenient to install an external machine. Five horses will be air cooled. There are about 5000- 10000 sets, and some of them are on the ground, so some insulation is needed. (The labor cost of thermal insulation material package is about150m3). Without heat preservation, it can be maintained at around 17-20, which also consumes electricity. There is also 3-phase 380 electricity when 5 machines are running. It is a little difficult for residents to use 220 electricity.