An instant water heater, also known as a tankless water heater, is a device that heats water on demand and without a storage tank:
How it works
When a hot water faucet is turned on, cold water flows into the water heater and is heated by an electric element or natural gas burner. The water is heated in a heat exchanger and then flows out through an outlet pipe as hot water.
Benefits
Instant water heaters can provide a constant supply of hot water and are ideal for small living areas. They are also more efficient than storage water heaters, which only hold a limited amount of hot water.
Types
Instant water heaters can be powered by electricity or gas. Copper heat exchangers are often used in these units because they are easy to fabricate and have high thermal conductivity. However, copper heat exchangers are more likely to build up scale than stainless steel heat exchangers.
Price
Instant water heaters are generally less expensive than storage water heaters