Upgrading to a more efficient air conditioner costs more upfront but saves money on electricity over time. The payback period tells you when those savings exceed the extra cost.
Understanding Payback Period
Payback period = (Extra upfront cost) ÷ (Annual electricity savings)
Example: If an efficient AC costs 8,000 THB more but saves 3,000 THB per year in electricity, the payback period is 2.7 years.
Factors That Affect Payback
1. Usage Hours
More usage = faster payback. An AC running 12 hours daily will pay back twice as fast as one running 6 hours.
2. Efficiency Difference
The bigger the EER gap between old and new units, the greater the savings.
- EER 9 → 11: Save ~20%
- EER 9 → 12: Save ~25%
- EER 9 → 14: Save ~35%
3. Electricity Rates
Higher electricity costs mean faster payback. Thailand's progressive rates mean heavy users pay more per unit, making efficiency more valuable.
4. AC Size
Larger ACs consume more electricity, so efficiency improvements yield bigger absolute savings.
Typical Payback Scenarios
| Scenario | Payback Period |
| Heavy use (10+ hrs), high efficiency gain | 1-2 years |
| Moderate use (6-8 hrs), moderate efficiency | 2-4 years |
| Light use (3-5 hrs), small efficiency gain | 5+ years |
When Upgrading Makes Sense
- Payback under 3 years: Excellent investment
- Payback 3-5 years: Good if AC has remaining lifespan
- Payback over 5 years: Consider only if current AC needs replacement
Calculate Your Payback
Use our Payback Period Calculator to see your specific scenario, and Electricity Cost Calculator to estimate savings.