Air energy water heaters work by absorbing most of the heat from the surrounding ambient air and transferring it to the water while consuming a certain amount of electricity to achieve an increase in water temperature. If an air water heater is installed directly indoors, the indoor space is limited, and the available heat in the air of the limited space is also limited, which will lead to a reduction in the efficiency of the air water heater, longer time to heat the water, and even in winter, leading to a further reduction in the temperature in the room.
Air water heater installed in the open balcony, very well ventilated bathroom or kitchen, more open underground garage is possible, but to avoid the air water heater winter use consume the room heating heat. Currently more common installation is the overall domestic air water heater installed directly on the open balcony, split air water heater outdoor unit mounted directly on the external wall.