Air conditioning can be essential for home comfort, especially during hot weather. Understanding how air conditioners work and how to choose an energy-efficient system can help you save on energy costs and reduce your carbon footprint.
Importance of Air Conditioning
- Widespread Use: 88% of homes in the United States have air conditioning, and 66% have central systems.
- Energy Consumption: Air conditioners use about 12% of the electricity in U.S. households, with costs varying by location. Annually, this adds up to about $29 billion for homeowners.
- Environmental Impact: Air conditioning contributes significantly to carbon dioxide emissions, releasing over 100 million metric tons annually.
If you're in the market for a new air conditioner, choose one with the ENERGY STAR® label to optimize electricity savings and reduce your system's carbon footprint.
How Air Conditioners Work
Air conditioners operate similarly to refrigerators, transferring heat from your home’s interior to the outside environment.
- Components:
- Evaporator Coil (Indoor Coil): This cold coil absorbs heat from the indoor air.
- Condenser Coil (Outdoor Coil): This hot coil releases the absorbed heat outside.
- Compressor: The electric motor-driven pump circulates refrigerant between the evaporator and condenser.
- Process:
- The refrigerant evaporates inside the evaporator coil, absorbing heat from the indoor air and cooling your home.
- The heated refrigerant gas is pumped to the condenser, where it releases heat to the outside air and reverts to a liquid state.
Evolution of Refrigerants
- Past Refrigerants: Initially, air conditioners used chlorofluorocarbons (CFCs), but these were phased out due to their harmful effects on the ozone layer.
- Current and Future Refrigerants: Today, hydrofluorocarbons (HFCs) and the latest low-carbon A2L refrigerants are used, with alternatives like CO2 and ammonia being explored for their environmental benefits.
Selecting an Energy-Efficient Air Conditioner
- Look for ENERGY STAR®:
- Choose units with the ENERGY STAR® label to ensure high energy efficiency and lower carbon emissions.
- Efficiency Rating:
- The Energy Efficiency Ratio (EER) measures efficiency. Higher EER ratings indicate more efficient air conditioners. As of January 2023, the EER2 rating is used, which is more stringent.
- Proper Sizing:
- Ensure the air conditioner is correctly sized for the space. Too large a unit can lead to inefficient operation and poor dehumidification, making the room feel uncomfortable.
- Typically, an air conditioner needs 20 BTU for each square foot of living space. Consider room height, local climate, shading, and window size.
- Electrical Requirements:
- Smaller units (less than 7.5 amps) can use standard household circuits, while larger units require dedicated circuits. Verify your home’s electrical system meets the unit’s requirements.
- Additional Features:
- Directional Airflow: Look for units that can direct airflow where needed.
- Ease of Maintenance: Choose units with easily accessible filters for cleaning.
- User-Friendly Controls: Opt for digital thermostat readouts, built-in timers, and mobile app controls.
Choosing the right air conditioner and maintaining it properly can significantly improve your home's comfort while saving energy and reducing your environmental impact. By understanding how air conditioners work and selecting an energy-efficient model, you can enjoy a cooler home and lower energy bills.
Take Action
For more tips on optimizing your home’s cooling system, improving energy efficiency, and reducing your carbon footprint, explore our Energy Saver 101 infographic on home cooling. If you’re ready to purchase, look for the ENERGY STAR® label to ensure you’re getting the most efficient system available.
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