Tankless water heaters used to be something straight out of science fiction. With their ultra-efficient system and their sleek footprint, they have been changing the game of water heating technology. But how do they work? What makes a tankless water heater so much quicker and more efficient than traditional water heaters?
In this article, we will dive deep into the technology behind the tankless water heater and explore the wonders of just how they work.
What Is A Traditional Water Heater?
Before we can dig into the nuances of tankless vs. tank water heaters, it is important to know exactly what a traditional water heater does. Traditional water heaters, also known as storage tank water heaters, operate on a relatively simple principle. It utilizes an insulated tank that can hold a specific volume of water, and is typically made of steel.
Cold water will enter the tank through an inlet pipe, which is then heated to a level set by a thermostat controller. There are two main types of ways that traditional water heaters warm up the water. Electric and gas.
1. Electric Water Heater
In a traditional electric water heater, one or more electric heating elements will heat the water. Each element consists of an electrical resistor that heats up when an electric current passes through it. Electrical storage water heaters are the most common household water heaters.
2. Gas Water Heater
Another type of traditional water heater is the gas-powered water heater. This style of water heater utilizes a gas burner that is located beneath the tank that heats the water. The burner is ignited by a pilot light or an electric ignition system and creates a flame that heats the surrounding area.
As whatever style of heater warms up the water at the bottom of the tank, convection currents are established. At this point, hot water begins to rise to the top of the tank, pushing down colder water. This process creates a natural circulation, ensuring that the entire volume of the water is gradually heated.
Tankless Water Heaters
In contrast to the “always on” storage style water heaters that are most common in homes across the United States, the tankless water heater heats water on demand. This means that tankless water heaters sit idle most of the time and are only turned on when hot water is needed.
Tankless water heaters have been around since Dr. Theodore Stiebel created the first electric tankless water heater in his backyard in 1927. However, once the EPA established Energy Star in 1992, it began to take off.
How Does It Work?
Tankless water heaters are complex but can be distilled down to six steps. They are:
- Flow Sensor Detects Water: When you open up a hot water faucet or turn on a hot water appliance, cold water enters through the tankless water heater through an inlet pipe.
- Heat Exchanger Is Triggered: Inside a tankless unit is one of two types of heat exchangers (electric or gas). For electric units, the heating coils turn on. For gas units, a gas valve opens, and a burner ignites.
- Temperature Control: Tankless water heaters have a control panel or digital interface that allows you to set the desired water temperature. The unit continuously monitors the incoming water temperature and adjusts the heating process to reach the desired output temperature.
- Heat Transfer: As cold water passes through the heat exchanger, it absorbs heat from the burner flame or electric heating element. The water is rapidly heated to the set temperature, providing instant hot water on demand.
- Continuous Flow: Tankless water heaters provide a continuous flow of hot water as long as the demand exists. The heating process is efficient and occurs in real time, meaning you do not have to wait for a storage tank to refill and reheat.
- Shut Off and Stand By Once you turn off the hot water faucet or appliance, the tankless water heater detects the decreased flow and shuts off the heating process. It enters a standby mode until hot water is needed again, minimizing energy consumption when not in use.
Advantages And Disadvantages Of Tankless Water Heaters
1. Advantages
If you are using less than 41 gallons of hot water a day, tankless water heaters can be as much as 34% more energy efficient than traditional storage tank water heaters. This can mean major savings over time. Not only will they cost less over time, but they are also better for the environment.
Due to the on-demand factor of tankless water heaters, you will technically never run out of hot water, even during long showers. Tankless water heaters are also a great way to save space, as they can be mounted on walls and have a compact design compared to bulky storage tank water heaters.
2. Disadvantages
It is important to know that tankless water heaters tend to have a much higher upfront cost compared to traditional storage tank heaters. The unit itself, along with installation expenses, can be more expensive. However, the long-term energy savings may offset the initial investment.
Additionally, tankless water heaters can only produce between 2–5 gallons per minute which can be a problem when you are trying to supply multiple uses in a large household. Tankless water heaters also may require more periodic maintenance and flushing to ensure optimal performance.
Tankless water heaters have installation limits, and if water supply conditions are not correct they are not recommended. Also, tankless water heaters consume a tremendous amount of energy as they must heat the water as fast as it flows through. Therefore if you use a lot of hot water, they will cost you more to operate than a traditional heater, not less.
Which Water Heater Is Right For Me?
While there are many different brands and styles of water heaters available on the market, it truly does depend on your needs whether or not you should get a tankless or storage water heater. In a perfect world, gas-powered tankless water heaters win out on efficiency and ability to handle the demand. However, this may not be possible due to the expense of the unit or the inability to use gas-powered appliances.
Whatever you choose, it is important to have your tankless water heater installed and maintained by professionals. We at Barlow Plumbing are trusted plumbers in Buncombe County. With decades of experience, there is no plumbing challenge we can't handle.
Let our team help you choose and install your new tankless water heater. Contact us today to schedule a consultation!