According to different designs, static heating air energy water heaters can be divided into built-in coil type with heat exchange coil placed in the water in the barrel and outer coil type with heat exchange coil coiled outside the barrel wall.
The advantage of built-in coil type is high heat exchange efficiency, but the disadvantage is that the coil is immersed in water, which is easy to rust and crack, leading to refrigerant flowing into the water and polluting the bath water.
The external coil does not have this health hazard problem. Although the heat exchange efficiency is not direct contact heat conduction, the safety is guaranteed, so the heating mode of the outer coil is better.