If a ceiling fan is not enough to cool a particularly warm room in your home, you may be considering buying a room air conditioner.
Room air conditioners (window air conditioners) cool rooms rather than the entire home. Using them as such, they are less expensive to operate than central air conditioners, even though their efficiency is generally lower than that of central units.
A room air conditioner's efficiency is measured by the energy efficiency ratio (EER). When buying a new room air conditioner, for greater savings select the unit with the highest EER.
Check the EnergyGuide label on the unit to compare its estimated annual electricity use with that of similar models. Also look for room air conditioners with the ENERGY STAR® label. ENERGY STAR-qualified room air conditioners use at least 10% less energy than conventional models.
Following are some energy-saving tips for buying and using a room air conditioner:
- Proper sizing is very important; a bigger unit is not necessarily better. A small unit running for an extended period operates more efficiently and is more effective at dehumidifying than a large unit that cycles on and off too frequently.
- Install the unit in a shaded spot. Direct sunshine on the unit's outdoor heat exchanger decreases its efficiency by as much as 10%.
- Don't place lamps or televisions near your air conditioner's thermostat because their heat can cause the air conditioner to run longer than necessary.
- Set your air conditioner's thermostat as high as is comfortably possible, minimizing the difference between the indoor and outdoor temperatures.
- Don't set your thermostat at a colder setting than normal when you turn on your air conditioner; it will not cool your room any faster.
- Set the fan speed on high, except on very humid days. On humid days the low fan speed will cool your room better and will remove more moisture from the air because of slower air movement through the cooling equipment.
- Consider using an interior fan in conjunction with your air conditioner to spread the cooled air more effectively. And you can save money by raising the thermostat on your air conditioner or by using it for shorter periods of time.
For more guidance on selecting a room air conditioner, go to:
www.energystar.gov/roomac
