The difference between EER (Energy Efficiency Ratio) and SEER (Seasonal Energy Efficiency Ratio) lies in the scope of their measurements and the timeframes over which they assess an air conditioner’s energy efficiency.
- EER (Energy Efficiency Ratio):
- EER is a measure of an air conditioner’s energy efficiency at a specific operating condition: outdoor temperature of 95°F (35°C), indoor temperature of 80°F (27°C), and 50% relative humidity.
- It is calculated by dividing the cooling capacity (in BTU/h) by the power consumption (in watts) under those specific conditions. The higher the EER rating, the more energy-efficient the air conditioner is at that specific point.
- SEER (Seasonal Energy Efficiency Ratio):
- SEER is a measure of an air conditioner’s energy efficiency over an entire cooling season, taking into account varying outdoor temperatures and the air conditioner’s performance under different conditions.
- SEER considers a range of outdoor temperatures, simulating the typical climate variations throughout the cooling season. It reflects the cooling efficiency during both moderate and extreme weather conditions.
- The SEER rating is calculated by dividing the total cooling output (in BTU) over a cooling season by the total energy consumption (in watt-hours) during that same period. The higher the SEER rating, the more energy-efficient the air conditioner is over the entire cooling season.
In summary, EER is a single-point measurement that indicates the air conditioner’s energy efficiency at specific operating conditions, whereas SEER provides a more comprehensive and realistic assessment of the system’s efficiency over a range of outdoor temperatures and climate conditions. SEER is a more reliable metric for evaluating the overall energy performance of an air conditioner, especially considering the varying weather conditions it encounters during a cooling season.
When choosing an air conditioner, it’s essential to consider both the EER and SEER ratings. A higher SEER rating generally indicates better energy efficiency and potentially lower operating costs over the cooling season, but EER can be valuable for comparing the performance of different units under specific conditions, such as extreme heat.