Water heaters are essential to our everyday existence, whether for cooking, washing, or taking showers. Understanding their inner workings can help us save money and energy through proper maintenance and smarter purchasing.
While traditional storage hot water tanks are still the standard, new technology is taking hold – heat-pump models that offer huge cost and energy savings compared to gas or electric resistance alternatives.
How Do Water Heaters Work?
Residential water heaters warm up cold water that runs through your plumbing pipes, so appliances like showers, washing machines, and clothes dryers can output hot water for you to use. They also hold heated water, so they’re ready to use when you open a tap.
Tank-style gas water heaters have a large steel tank and a burner. The gas regulator and thermostat control the temperature of water inside the tank.
The tank has an exhaust flue that runs through its center to channel exhaust gases out of the house through a chimney or vent pipe. The flue has a spiral metal baffle that catches heat and conveys it to the water. This increases the heater’s efficiency. Once the flue ends, it shuts off the gas to the burner.
Tank Water Heaters vs. Tankless Water Heaters
Tank water heaters have a large insulated storage tank that keeps hot water until needed. They use gas, electricity, or propane to heat the water and are the most common in homes today.
Tank storage water heaters can take longer to deliver hot water to your home and may run out of hot water during peak usage. They are also less energy-efficient than other types of water heaters.
While they provide long-term savings on your energy bill, installing a tankless water heater will cost more upfront due to the plumbing and electrical changes required in your home. However, you can receive rebates from your utility company to offset the costs. Seek a certified professional residential water heaters San Francisco CA, to complete the installation.
Tank-type heaters waste energy by heating and reheating water at all times, regardless of your water needs (a process called standby heat loss).
They also have limited capacities, so they often run out of hot water if multiple people in the house use their showers simultaneously. They take up more space than tankless units and can’t be installed outside.
How Do Tankless Water Heaters Work?
As their name suggests, tankless water heaters don’t use storage tanks. Instead, they heat water on demand when a hot water tap is turned on.
When you turn on your hot water faucet, a flow sensor activates the unit by sending cold water into the unit’s heat exchanger. A gas burner or electrical element then heats the water. The hot water exits your fixture at two to five gallons per minute (gpm).
Electric tankless models typically feature a heat pump. They work similarly to a refrigerator working in reverse by moving heat from the air to the water, and as a result, they require an extensive electrical system in your home. Some older homes require an electrical system upgrade before installing an electric whole-home tankless model.
When you turn on your hot tap, tankless water heaters heat the water as it goes through a thermal exchanger. They are more expensive to purchase and install, but they can save you money over time with energy savings and rebates from utility companies.
You can choose a whole-house model that serves all your household appliances and fixtures or a “point-of-use” model installed near each fixture to reduce lag time. Both types of electric tankless water heaters don’t require ventilation, but they draw a lot of power, and your electrical system may need to be upgraded to support them.
Gas models have different venting and gas supply requirements, and they must be connected to a more extensive diameter gas line for proper operation. They also cost more to install than electric models.