Efficient Hot Water
Heaters and Boilers
Specify Energy
Star compliant boilers and service water heaters, with higher efficiencies
than the legally required minimum.
Small, mid-efficiency
atmospherically vented service water heaters and boilers equipped
with vent dampers, powered burners, more insulation and often intermittent
ignitions have Energy Factors (EF) ranging from 0.62 to 0.70, at
a small premium over standard equipment.
Direct-vent,
sealed-combustion and condensing water heaters and boilers have
the best EFs -up to 0.86, though at a capital cost premium. Paybacks
are typically attractive, and these units provide greater flexibility
in vent location, and minimize the risk of indoor air quality problems.
Energy Star
compliant gas service water heaters must use less than 242 therms/year;
electric units less than 4700 kWh/year, verified by independent
testing. Energy Star boilers must have Annual Fuel Utilization Factors
of 85% or greater.
The Environmental
Protection Agency’s Energy Star program offers attractive loans
to contractors and homeowners for these purchases.
Cautions
- Compare capital
costs and internal rate of return of alternate equipment options
where capital costs are tightly constrained.
- Ensure that
proposed substitutions for specified equipment also comply with
efficiency requirements, and are certified by the Energy Star
program.
