When shopping for an air conditioner, you'll encounter efficiency ratings like EER and SEER. Understanding these numbers can save you thousands on electricity bills over your AC's lifetime.
What is EER?
Energy Efficiency Ratio (EER) measures cooling output (BTU) divided by power input (watts) at a specific temperature (95°F/35°C). Higher EER = more efficient.
Example: A 12,000 BTU AC using 1,200 watts has an EER of 10.
What is SEER?
Seasonal Energy Efficiency Ratio (SEER) measures efficiency across an entire cooling season with varying temperatures. SEER is typically higher than EER because it includes mild weather when AC works less hard.
EER vs SEER Comparison
- EER: Single temperature measurement, better for hot climates with constant AC use
- SEER: Seasonal average, better for varied climates
Minimum Standards
Most countries require minimum efficiency standards:
- Thailand: Level 5 label requires EER ≥ 11.0
- US: Minimum SEER 14-15 for new units
- Europe: A+++ rating = SEER ≥ 8.5
How Much Can You Save?
Upgrading from EER 9 to EER 12 saves about 25% on cooling costs. For an AC running 8 hours daily, that's 3,000-5,000 THB per year.
Calculate Your Savings
Use our EER/SEER Calculator to compare different models, and check Thai Energy Standards for compliance.