Data Manual

20
Heat pumps save energy and cost less to operate than
units with electric resistance heaters as the only heat
source. Just as the EER (Energy Efficiency Ratio) of an
air conditioner is an indication of the efficiency of the unit,
COP (Coefficient of Performance) is the indication of the
efficiency of the heat pump. This relative efficiency of a heat
pump compares the unit to electric resistance heat. If a unit
has a COP of 3.0, it means the unit will produce three times
as much heat at rating conditions for the same electrical
input wattage used for electric resistance heat.
GE Zoneline heat pumps are designed to provide
cost-efficient heat pump operation while monitoring
room conditions to maintain comfort.
The Zoneline AZ65 series employs extensive software
and logic that monitors and reacts to both outdoor
and indoor temperatures to determine the heat source.
This increases energy savings by operating longer
in the heat pump mode.
Just as in air conditioning operation, the compressor
is used in heat pump operation. The difference is that
in heat pump operation, the hot refrigerant gas is
directed to the indoor coil rather than to the outdoor
coil. With the indoor fan, room air circulates over the
indoor coil, gains heat from the coil and distributes
it into the room.
At some point as the outdoor temperature falls, the heat
pump cannot extract as much heat from the outdoor air
to maintain the temperature of the room. For this reason,
all packaged terminal heat pumps also have electric
resistance heaters as backup to heat pump operation.
The point where Packaged Terminal Heat Pumps cease
heat pump operation and change to the more expensive
resistance heat (to maintain room temperature) is called
the “switchover point.” It is important to compare the
switchover point of the various manufacturers since it
may occur at higher outdoor temperatures with other
brands where savings from the GE Zoneline heat pump
operation could still be realized.
Zoneline AZ65 series heat pump units, with their
extensive software and features, react to the indoor and
outdoor temperatures to determine the best heat source
to provide comfortable room conditions for the guest
AND energy.
BALANCE POINT
An important consideration in the selection of a heat
pump unit is the “balance point” of the installation—
the point at which the heat pump is unable to produce
enough heat to compensate for the heat loss of the room
or area being heated.
Virtually every room is unique—with different insulation,
different sizes and types of windows, different types
of construction and different directional exposures.
All these variables, as well as geographical location,
must be considered in order to determine the balance
point. For these reasons, a professional engineer should
be engaged to calculate the heat loss of the space and
specify the heat pump unit required.
HEAT PUMPS & ENERGY SAVINGS
ARCHITECTS & ENGINEERS DATA MANUAL AZ45/AZ65 SERIES