... 2.Save energy Air source heat pump water heater (household series): Heat pump water heater is built on a new power-saving ... of power-saving environment protected device succeeding electric water heater, gas water heater and solar energy heater. Heat pump water heater makes use of the cycle principle, ... to install. It can be put on the roof, in the balcony, in the courtyard, indoors, etc. And it can be ...