Energy-efficient tankless electric water heaters, also known as on-demand water heaters, work by heating water directly as it flows through the unit without the need for a storage tank. Here’s how they operate:
- Water Inlet: When you turn on a hot water tap or appliance, cold water from the main water supply enters the tankless water heater through an inlet pipe.
- Flow Sensor: Inside the unit, a flow sensor detects the water flow rate. This sensor is crucial because it determines when to activate the heating elements.
- Heating Elements: Once the flow sensor detects water flow, it signals the heating elements to start heating. Electric tankless water heaters have one or more high-powered heating elements (typically made of copper or stainless steel) that are activated to heat the water.
- Temperature Control: A built-in thermostat measures the temperature of the incoming cold water and the desired hot water temperature set by the user. The thermostat regulates the heating elements to reach the desired output temperature.
- Heat Exchanger: As water flows over the heating elements, it gets heated almost instantly. The heat exchanger in the unit helps maximize heat transfer efficiency. The water is heated as it passes through the heat exchanger and exits the unit as hot water.
- Hot Water Outlet: The now-heated water flows out of the unit through a separate hot water outlet pipe and is ready for use at the desired temperature.
- Continuous Flow: Tankless electric water heaters can provide a continuous supply of hot water as long as there is a demand for it. Unlike storage tank water heaters, there is no waiting time for the tank to fill and heat up, making them energy-efficient because they only heat water when needed.
- Shutdown: When you turn off the hot water tap or appliance, the flow sensor detects the reduced flow or the absence of flow and shuts off the heating elements. This saves energy because the unit isn’t continuously heating water.
Energy-efficient tankless electric water heaters offer several advantages, including lower energy consumption, a smaller footprint, and the ability to provide a constant supply of hot water. However, their performance can be influenced by factors such as the unit’s size, the incoming water temperature, and the flow rate, so it’s important to choose an appropriately sized unit for your specific needs.