The higher the ef number.
Which is more efficient gas or electric hot water tank.
Department of energy to help consumers compare the efficiency of similar appliances.
Tankless gas water heaters and electric tankless water heaters are more expensive up front and may require you to upgrade your electrical systems.
For homes that use 41 gallons or less of hot water daily demand water heaters can be 24 34 more energy efficient than conventional storage tank water heaters.
You ll find both gas and electric models.
The efficiency of an electric water heater unit can be as high as 99 percent while gas units have an efficiency of up to 80 85 percent.
Propane models have the same pros and cons as natural gas units but propane is a more expensive fuel.
The bigger the ef number the more efficient the appliance.
Electric units can also last longer compared to gas water heaters and offer lower installation costs.
A gas or electric water heater s energy factor ef is a measurement that compares the amount of hot water the heater produces per day to the amount of fuel it consumes.
Most gas fired water heaters have an energy factor ef number set by the u s.
They require adequate airflow for combustion.
Also if you have a larger home you may need more than one.
They re more energy efficient than a storage tank but provide only a limited flow of hot water per minute about 3 5 gallons depending on inlet water temperatures.
On the other hand.
Efficiency standards for gas and electric water heaters are different but both use the uniform energy factor uef ratings system where higher scoring units produce more hot water while using less energy.
Natural gas models come in a variety of sizes types and efficiencies.
Can be vented through a chimney or wall.
And can provide hot water during power failures if they have continuous pilot lights.
We rated the annual energy consumption cost excellent for a gas.
They can be 8 14 more energy efficient for homes that use a lot of hot water around 86 gallons per day.
In all aspects electric tankless water heaters offer higher efficiency longevity and more.
Standard gas water heaters have an ef of about 50 to 60.
This is due to the way that the heaters operate.
A gas heater must vent the spent gas which also takes some of the heat with it.
To earn an energy star certification for example electric water heaters with tanks up to 55 gallons must have a uef greater than 2.