Generally speaking, air can use a quarter of the electricity of electric water heaters, so it saves electricity.
If you install it yourself, you should probably calculate the water consumption, which is usually one ton of water per machine. If the water consumption is large, it is best to divide it into two sets, for example, two five-horse machines are used for ten tons of water, so that if one machine fails and the other machine is propped up, of course, ten horses can be matched with one.
Generally, it is no problem to use it for a few years.
Air energy is generally equipped with an insulated water tank, which is stored after heating, automatically heated when the temperature drops, and automatically stopped when the temperature is enough.