Environmental Engineering Reference
In-Depth Information
conditioner, when in cooling mode, the heat is removed from the room being
cooled and pushed outside through the refrigeration system. Similarly, if the
unit can operate in 'reverse' (the so-called heating mode or reverse cycle),
the process runs backward and the energy is collected from outside and
moved inside to the room being heated.
1. Performance: To be eligible for an energy label (and to comply with
MEPS), an air conditioner must meet the maximum cooling test as
defined in the Australian standard; this ensures that the air condi-
tioner is capable of operating under extreme conditions. The air con-
ditioner also has to have a tested capacity of not less than 95% of the
rated value and a tested energy consumption of not more than 105%
of the rated value.
2. Star rating: The star rating for air conditioners is determined dif-
ferently than for other appliances. For air conditioners, the measure
of energy efficiency is the EER for cooling and the COP for heating.
The EER and COP are defined as the capacity output divided by the
power input. The star rating index is calculated on the tested values
for energy and capacity, rather than the nameplate or rated values.
Typically, the EER and COP are in the range 2.0-3.5 (meaning that the
cooling or heating output is 2-3.5 times as great as the power input, or
an efficiency of 200%-350%). This is achieved by the use of a refrigera-
tion heat pump that collects internal heat and moves it outside when in
cooling mode or collects ambient heat from outside and moves it inside
when in heating mode. The apparent efficiency of heat pumps is high
because they can move much lower grade energy in the form of heat
than they require as electrical power input. The star rating for air con-
ditioners is determined from the tested EER and COP. For cooling, one
star is equal to an EER of 2.0 with an extra star for an increase in EER
of 0.3. For heating, one star is equal to a COP of 2.3 with an extra star
for an increase in COP of 0.3. From 2010, one star was equal to an EER
and COP of 2.75 with a step of 0.5 for each additional star. Importantly,
from 2010, the star rating will be based on an annual efficiency calcula-
tion that includes any non-operational energy consumption.
What Do the Labels Look Like for Each of the Labelled Products?
1. Requirements for gas space heaters, gas water heaters and gas
cookers: Energy labels can be found on gas space heaters (AS4553
and AS4556) and gas water heaters (storage and instantaneous)
(AS4552). Gas energy labels are similar in format to those found
on electrical appliances, except they are blue in colour and annual
energy is shown in megajoule. The gas labelling programme is
currently an industry voluntary scheme that was once managed by
the Australian Gas Association (AGA).
