Residential Heat Pump Water Heater
solution to efficient electric heating, The Problem: How
to Convince Consumers to Save Energy in Water Heating
half of all
domestic water heating is done with electric resistance storage water heaters.
The most efficient resistance water heater has an energy factor (EF) of 0.95,
only 5% below the maximum efficiency possible for that type of water heater.
Yet by using electricity to "pump heat" from the surrounding space,
the residential heat pump water heater (HPWH) can attain much higher
efficiencies, reducing the electricity needed for water heating by at least
efficiencies, today's U.S.
market for residential HPWHs is small and stagnant (less than 2,000 units/year)
and is served by only two or three manufacturers.
has the HPWH market
by DOE and others point to a number of issues:
Economics — High first
cost, leading to long payback time.
of early models created a poor reputation for the HPWH.
infrastructure lacking; specialized training and familiarity are required.
not well-suited to universal installation; easier to replace like-for-like.
not aware of HPWH benefits; few have even seen one.
from a strong
understanding of these technical and market issues, Enviromaster International
(EMI) and Arthur D. Little, with support from the DOE ENERGY STAR Program
through Oak Ridge National Laboratory, are developing a unique
"market-optimized" ambient-air HPWH aimed at the large electric water
heater replacement market.
"drop-in" replacement for 50- or 80-gallon electric water heater —
same footprint as the original water heater, an identical electrical hookup, no
need for additional plumbing, and no condensate drain required
compressor — robust, proven, inexpensive, small, yet with sufficient capacity
for meeting most water heating demands
no water pumps
hot water tank; no additional penetrations
work anywhere that
a conventional resistance water heater will work — basements, closets, garages,
by plumber — no additional skills needed.