... average COP in winter is up to around 4.5With the overall design, built-in almost all ... start control for single phase power supply models.4) Water flow switch equipped for water flow protection.5) Careful ... freezing, phase order, discharge temp, etc.6) Flow switch for water flow protection.7)) Full sealed control box ... 380V/3ph/50hz/60hzHeating capacity:3kw to 4kwCOP:4.5 Payment: T/T,L/C are acceptable ...