To choose an energy-efficient heater, look for models with high energy ratings, programmable thermostats, and features like zone heating to reduce energy costs.
Selecting an energy efficient heater can significantly reduce your utility bills while keeping your home comfortable. With various types, sizes, and technologies available, making the right choice requires understanding key factors like fuel type, efficiency ratings, and proper sizing.
Types Of Energy Efficient Heaters
Different heater technologies offer varying levels of efficiency and performance. Consider these options:
Heat Pump Water Heaters
These are 2-3 times more energy efficient than conventional electric resistance water heaters. They work by moving heat from the surrounding air into the water tank rather than generating heat directly. The Stiebel Eltron Tempra 36 is an excellent example of an efficient heat pump model.
Tankless Water Heaters
Also called on-demand heaters, these provide hot water only when needed, eliminating standby energy losses. They can be 24-34% more energy efficient than conventional storage tank heaters for homes that use 41 gallons or less of hot water daily.
Solar Water Heaters
These systems use free energy from the sun to heat water. While the upfront cost is higher, they can reduce water heating bills by 50-80%. The XtremepowerUS solar heater demonstrates how this technology can be applied effectively.
Key Efficiency Factors To Consider
Energy Factor (EF) Rating
The Energy Factor measures overall efficiency based on recovery efficiency, standby losses, and cycling losses. Higher EF ratings indicate better efficiency:
| Heater Type | Typical EF Range |
|---|---|
| Electric Resistance | 0.75-0.95 |
| Heat Pump | 2.0-3.5 |
| Gas Storage | 0.50-0.70 |
| Tankless Gas | 0.80-0.94 |
First Hour Rating (FHR)
This indicates how much hot water the heater can deliver in an hour when starting with a full tank. Match this to your household’s peak demand.
Uniform Energy Factor (UEF)
A newer metric that provides a more accurate comparison between different heater types. Like EF, higher numbers indicate better efficiency.
Proper Sizing For Maximum Efficiency
An oversized heater wastes energy, while an undersized one can’t meet demand. Follow these guidelines:
For Storage Water Heaters
- 1-2 people: 30-40 gallon tank
- 3-4 people: 40-50 gallon tank
- 5+ people: 50-80 gallon tank
For Tankless Heaters
Calculate your maximum flow rate by adding up the gallons per minute (GPM) of all fixtures that might run simultaneously. Most tankless units provide 2-5 GPM.
Fuel Type Considerations
The energy source impacts both efficiency and operating costs:
Electric Heaters
While often 100% efficient at point of use, electricity can be expensive depending on your local rates. Heat pump models offer the best efficiency.
Gas Heaters
Natural gas is typically cheaper than electricity, with tankless models offering the highest efficiency (up to 94% AFUE). The Rinnai RL94EN is a top-performing gas model.
Propane Heaters
Good option where natural gas isn’t available. Consider indoor propane space heaters for supplemental heating.
Advanced Features For Efficiency
Modern heaters include smart features that optimize energy use:
- Programmable thermostats for customized schedules
- Wi-Fi connectivity for remote control and monitoring
- Vacation modes that reduce output when you’re away
- Leak detection systems that prevent water waste
- Recirculation pumps that reduce water waste while waiting for hot water
According to Energy.gov, choosing an ENERGY STAR certified water heater can save a typical family about $300 or more over the life of the appliance.
Installation Considerations
Proper installation is crucial for efficiency:
- Insulate hot water pipes to reduce heat loss
- Install heat traps on storage tank models
- Place the heater close to points of use to minimize pipe runs
- Ensure adequate ventilation for combustion models
- Consider a professional installation for complex systems
For maximum savings, combine an efficient heater with other conservation measures like low-flow fixtures and insulation. The ENERGY STAR program provides excellent resources for comparing efficient models.
