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Energy Saving Room Air Conditioning



About Room Air Conditioning Efficiency:


An average air conditioned home consumes more than 2000 kilowatt-hours of electricity per year for cooling, causing about 3,500 pounds of carbon dioxide and 31 pounds of sulfur dioxide to be emitted by the power plant. At average electricity prices, that costs about $150. A high-efficiency A/C unit can reduce energy consumption (and environmental emissions) by 20% to 50%. The most efficient air conditioners on the market are up to 70% more efficient than the current average room air conditioner.


Tips for Lowering Your Room Air Conditioner Energy Usage:

  • While fans cannot replace air conditioners, they can provide supplemental cooling, especially on mild summer days. Substituting fans for air conditioners can reduce energy use by 60% or more.

  • Consider installing a programmable thermostat if you do not have one. You can save as much as 10% on your cooling bill by simply turning your thermostat back 10 to 15 degrees for 8 hours. You can do this easily using a programmable or a setback thermostat.

  • Set your thermostat as high as comfortably possible in the summer. The less difference between the indoor and outdoor temperatures, the lower your overall cooling bill will be.

  • Don't set your thermostat at a colder setting than normal when you turn on your air conditioner. It will not cool your home any faster and could result in excessive cooling and, therefore, unnecessary expense.

  • Room air conditioners must be installed on a flat, even surface so that the inside drainage system and other mechanisms operate efficiently.

  • Set the fan speed on high, except on very humid days. When humidity is high, set the fan speed on low for more comfort. The low speed on humid days will make for a more comfortable home by removing more moisture from the air.

  • Consider using an interior fan in conjunction with your window air conditioner to spread the cooled air more effectively through your home without greatly increasing electricity use.

  • Don't place lamps or televisions near your air-conditioning thermostat. The thermostat senses heat from these appliances, which can cause the air conditioner to run longer than necessary.

  • It is important to install the unit in a shaded spot on the home's north or east side because direct sunshine on the unit's outdoor heat exchanger decreases efficiency.

  • Plant trees and shrubs to shade air-conditioning units but do not block the air flow. A unit operating in the shade uses as much as 10% less electricity than the same one operating in the sun.

  • Room air conditioners should be covered or removed and stored in winter.

  • Check your unit's air filter once a month and clean or replace filters as necessary. Keeping the filter clean can lower your air conditioner's energy consumption by 5% to 15%.

  • Clogged drain channels prevent a unit from reducing humidity, and the resulting excess moisture may discolor walls or carpet. Channels usually can be cleared by passing a stiff wire through them.

  • Holes in the seal between the air conditioner and the window frame allow cool air to escape from your home. Moisture can damage this seal, so inspect the seal annually to ensure it makes contact with the unit's metal case.

Tips for Buying a New Room Air Conditioner:

  • When shopping for an air conditioner, first determine which type of system best suits your needs- central air conditioning or room air conditioning. Central air conditioners are designed to cool an entire house, while room air conditioners are usually window- or wall-mounted units that only cool the immediate area.

  • Three types of room air conditioners are available: (1) window models that can be installed in most double-hung windows; (2) casement window models that are used in narrow, vertical windows, usually requiring the removal of a window panel for installation; and (3) built-in models that are encased in a sleeve installed in the wall.

  • Proper sizing is very important for efficient air conditioning. A bigger unit is not necessarily better because a unit that is too large will not cool an area uniformly. 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.

  • When determining the appropriate size air conditioner for your home, consider the dimensions of the area to be cooled. Based on size alone, an air conditioner generally needs 20 Btu for each square foot of living space. Other important factors to consider when selecting an air conditioner are room height, local climate, shading, window size, etc.

  • Verify that your home's electrical system can meet the unit's power requirements. Room units operate on 115-volt or 230-volt circuits. The standard household receptacle is a connection for a 115-volt branch circuit. Large room units rated at 115 volts may require a dedicated circuit and room units rated at 230 volts may require a special circuit.

  • If you are mounting your air conditioner near the corner of a room, look for a unit with an airflow in the desired direction for your room layout.

  • Look for a unit whose filter slides out easily for regular cleaning.

  • Select a unit with logically arranged controls, a digital readout for the thermostat setting, and a built-in timer.

  • When considering several comparable units, select the unit with the higher EER.

  • If you need to mount the air conditioner at the narrow end of a long room, then look for a fan control known as "Power Thrust" or "Super Thrust" that sends the cooled air farther into the room


U.S. EPA's ENERGY STAR Program, http://www.energystar.gov and the Los Angeles Department of Water and Powerer

Go to Clean Air Campaign home page
CAC home page

Go to Land-of-Sky Regional Council home page  
LOSRC home page

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e-mail: cleanair@landofsky.org