Novel Fan Design Offers Energy
Savings to Refrigeration Market
Senior Product Design Engineer
A. O. Smith Electrical Products Company
Patented PAX Scientific technology applied to
evaporator fans coupled with A. O. Smith motor produces
significant power reduction.
In many industries, consumer awareness, preference, and federal regulations are
challenging manufacturers to develop more energy efficient products. A small
reduction in the energy consumption of an electrical appliance can yield
tremendous savings when used in millions of homes. In refrigeration, achieving
ENERGY-STAR efficiency levels places a premium on developing reduced
power components such as evaporator (evap) and condenser motor/fan systems.
A more efficient evap stage also reduces loading on other large energy draw
components in the refrigeration cycle. Thus, the power contribution of the evap
component is especially important to overall refrigerator energy usage. Energy
savings at the evaporator stage also afford the manufacturer greater flexibility in
choosing and designing other components of the refrigeration system.
While traditionally comprising an axial fan with C-frame (skeleton) motor,
previous attempts to reduce evap power consumption have been costly, as
evidenced by the development of the brushless DC (BLDC) motor.
Also, pressure and flow characteristics of the evap system must remain similar
as energy savings are sought. If airflow is too low, then interior temperatures will
not be maintained without high evap run times, thereby negating any power
reduction benefit. Likewise, higher airflow pushes too much cold air from the
freezer compartment into the refrigerator proper, potentially causing problems
such as the freezing of refrigerated vegetables.
Breakthrough in Fan Performance
Fan design is a mature technological sector wherein performance and efficiency
improvements are typically minimal. A leading source of inefficiency for axial