room air conditionersIntroduction. Although less efficient than central air
conditioners, room air conditioners are often advantageous due to their
ability to isolate cooling areas, thus reducing the energy needed for
cooling. If most of our time indoors is spent in a single room, perhaps
an office, than it makes sense to cool just that room and not the
bathrooms, hallways, etc., which would require a central air
conditioning system. However, there is a limit to the number of room
cooling units one should use in a single building. If a number of units
are being used in the same locality of the building, then a more
efficient central air conditioning system may be a better choice. Before
buying or replacing a system look at ways to reduce the cooling load as
much as possible. This often allows much smaller units to be installed,
or in some cases may even reduce the need for air conditioning
altogether. Have a qualified air conditioning technician or energy
auditor size the unit needed in accordance to thorough analysis. Be sure
the analysis includes local climate information, calculations of heat
gain through windows and walls, and any of the initial conservation
efforts made. Choosing an inefficient model will lock you into high electric bills
for years to come, thus an efficient unit is just as important as is a
correctly sized unit. The efficiency of room air conditioners is
measured by the energy efficiency rating (EER), which is the ratio of
the cooling output (in BTU) divided by the energy consumption (in
watt-hours). Consider a room air conditioner with an EER greater than 9
to be efficient, and a model with an EER over 9.5 to be very efficient.
High-efficiency units generally cost more, but in hot climates (where
the air conditioner runs for more than 300 hours per year) more
efficient units pay for themselves over a few years through reduced
electricity bills. Operation. In order to perform at peak efficiency, a number of maintenance procedures should be performed. The air filters should be cleaned monthly, and the condenser should be cleaned by a professional every other year. During service of a unit, its refrigerant may need recharging. A 10% undercharged system can operate at 20% lower efficiency, but overcharged systems can have drastically reduced lifetimes. Thus units need to be charged correctly by licensed professionals. It is very important that the refrigerant not be allowed to leak into the environment, where the potential exists for further damage to the ozone layer. It is also a good idea to unplug the unit, or flip the circuit breaker if a switch does not exist, during the winter months. |