Natural gas water heaters offer several advantages over electric water heating:
- Cost – natural gas is cheaper than electricity, so operating costs are less
- Reliability – if the power goes out, tank model water heaters will continue to work
- Rapid Heating/High Recovery Rate – natural gas models heat water quicker than electric models
There are two basic types of natural gas water heaters, tank water heaters and tankless water heaters.
Tank Water Heaters
Tank water heaters store hot water on a stand-by basis and come in different sizes from 40 gallons to 100 gallons. These units store hot water in the tank, so it is ready when you need it.
Advantages of tank water heaters:
- Less expensive to purchase than tankless units
- Less expensive to operate that electric tank units
- Provides hot water, even during power outages
- Immediate hot water
- Quicker recovery times than electric tank units
Unlike conventional storage water heaters, tankless units only heat water as it’s used—on demand. When a hot water tap is turned on, cold water is drawn into the unit, and a sensor activates the internal heat exchanger. As the water flows through, it’s heated. The unit delivers a constant supply of hot water, but the flow rate is limited by the output of the heat exchanger.
Tankless water heaters offer a number of advantages over conventional (tank) storage units, including:
- Endless hot water
- Low maintenance costs
- Elimination of standby losses
- Small size frees up space in your home
- Average service life of 20 years more (compared to 10 to 12 years for storage units)
Tankless water heaters may cost more to purchase, but can pay for themselves through energy savings. Since tankless water heaters operate entirely “on demand” only when hot water is needed, thermal heat loss is almost completely eliminated, resulting in as much as a 50 percent savings in your water heating costs.
Finding the right water heater
Tankless models are rated by how many gallons of hot water they produce per minute (GPM) at a given temperature rise (minimum 60°F). Gas-fired condensing tankless water heaters cost more but provide even greater energy savings.
To size a tankless water heater, you’ll need to determine your hot water demand. An experienced plumber can provide an accurate estimate, but here are some average figures:
- Shower – 2.5 GPM
- Clothes washer – 3.3 GPM
- Dishwasher – 1.3 GPM
Consult with your installation contractor about correctly sizing a tankless model for your home or application.
Are tankless water heaters more efficient than tank water heaters?
The answer is yes, but it’s a little complicated. The efficiency of producing heat in a tankless water heater is essentially the same as for a storage water heater. However, in a tankless design, there are no storage losses.
Water heater efficiency is calculated by comparing the amount of heat energy in water drawn from the unit to the amount of fuel energy that goes in. For both electric and natural gas storage water heaters, heat from the stored water is radiated out into the air around the storage tank. Roughly 4 to 7 percent of the fuel energy is lost to the atmosphere.
So, the increased efficiency of tankless water heaters comes from saving that 4 to 7 percent of fuel energy that would be lost in a storage unit.
Additional benefits of tankless units include unlimited hot water supply, smaller equipment size and longer life expectancy.
Earn rebates up to $1,200 when you make the switch to tankless water heating. Learn more here.
How To Save On Water Heating Costs
Hot water is essential for home comfort, but it doesn’t come cheap. The average home uses 64 gallons of hot water each day and spends between $200 and $500 a year on water heating, according to the U.S. Department of Energy. If water heating is draining your household budget, these five tips will help keep the hot water flowing.
1. Conserve. It’s a simple premise: Use less hot water and your water heater will use less energy. Take shorter showers and avoid pre-rinsing dishes. If you do pre-rinse, use cold water. Wash clothes using cold water whenever possible, and only wash clothes and dishes only on a full load.
2. Lower the temperature of your hot water heater. Set your water heater temperature to 120°F. For every 10°F temperature reduction, you can save up to 5% in energy costs.
3. Fix leaks. When it comes to wasting energy and water, a leak is more than just a drop in the bucket. A typical leaky shower head can waste up to 500 gallons of water a year. Save money by quickly repairing leaks on faucets, shower heads and hot water pipes.
4. Install water-efficient fixtures. Low-flow shower heads and aerator faucets can reduce water use and save on energy costs. Water-efficient fixtures typically cost no more than $10 to $20 and provide water savings of 25% to 60%.
5. Insulate pipes. Insulating accessible hot water pipes located within three feet of the tank can raise the water temperature and reduce heat loss. Use pipe insulation wrap or foam pipe sleeves. Fasten the insulation securely and match the insulation to the diameter of the pipe. Pipe insulation kits are available at DIY or hardware stores.
If your water heater, dishwasher or clothes washer is older or in need of repair, consider upgrading to a new ENERGY STAR®-certified model. ENERGY STAR products use less energy than standard units.