An EER chart for air conditioners provides a convenient way to compare cooling efficiency across different types of AC equipment. The benchmarks differ for central air conditioners, window ACs, ductless mini-splits, and portable units, so an EER value should always be evaluated within the appropriate equipment category.
For a central air conditioner, an EER of around 11.5 or higher can generally be considered good, which corresponds to approximately 11.0 EER2. An excellent rating starts around 13 EER, or approximately 12.4 EER2. For window air conditioners, an EER of 11 or higher is generally considered good, while ductless mini-split systems typically reach the good range at around 13 EER.
The charts below provide a quick reference for determining whether an air conditioner falls into the poor, average, good, very good, or excellent efficiency category.
Central Air Conditioner EER/EER2 Chart
The following chart classifies central air conditioners according to their EER and EER2 values:
| Efficiency Level | EER | EER2 | Typical Description |
|---|---|---|---|
| Poor | Below 9.5 | Below 9.0 | Older technology with significantly higher electricity consumption |
| Below Average | 9.5–10.5 | 9.0–10.0 | Entry-level single-stage equipment that meets older minimum requirements |
| Average | 10.5–11.5 | 10.0–11.0 | Current single-stage or basic two-stage systems |
| Good | 11.5–12.5 | 11.0–12.0 | Quality two-stage or entry-level variable-speed equipment |
| Very Good | 12.5–13.5 | 12.0–13.0 | Premium variable-speed systems with high efficiency |
| Excellent | 13.5+ | 13.0+ | Top-performing variable-speed inverter systems |
Important Note on the Federal 25C Tax Credit
The 25C federal tax credit threshold shown here is historical and expired on December 31, 2025. Through the end of 2025, a central air conditioner generally needed to achieve 12.0 EER2, together with 17.5 SEER2, to meet the efficiency requirement associated with the $600 25C credit.
The credit expired for 2026 installations following the OBBBA (PL 119-21), signed on July 4, 2025. Nevertheless, the 12.0+ EER2 and 17.5+ SEER2 levels can still serve as useful efficiency benchmarks when evaluating state or utility rebate programs and performance-based programs such as IRA HOMES, where applicable.
Window Air Conditioner EER/CEER Chart
Modern window air conditioners commonly use CEER (Combined Energy Efficiency Ratio) instead of the older EER measurement. CEER also includes electricity consumed while the unit is in standby mode. Therefore, when using an EER chart for air conditioners, window AC efficiency is often evaluated using CEER values.
The following EER rating chart provides useful reference ranges for different window AC capacity classes.
| Cooling Capacity | Lower Efficiency | Average | Good | Excellent |
|---|---|---|---|---|
| 5,000–5,999 BTU | Below 10 | 10–11 | 11–12 | 12.1+ |
| 6,000–7,999 BTU | Below 10 | 10–11 | 11–12 | 12.1+ |
| 8,000–10,999 BTU | Below 9.5 | 9.5–10.5 | 10.5–12 | 12.1+ |
| 11,000–13,999 BTU | Below 9 | 9–10 | 10–11.5 | 11.3+ |
| 14,000–19,999 BTU | Below 9 | 9–10 | 10–11 | 10.8+ |
| 20,000–24,999 BTU | Below 8.5 | 8.5–9.5 | 9.5–10.5 | 10.0+ |
Larger window air conditioners often have somewhat lower EER values because the relationship between the compressor and cabinet size becomes less favorable as capacity increases. This is a normal equipment characteristic. Therefore, window ACs should preferably be compared with other units in the same cooling-capacity range.
Ductless Mini-Split EER Chart
Ductless mini-split systems generally achieve some of the highest EER ratings among residential air-conditioning equipment. In an EER chart for air conditioners, mini-splits often fall into the higher-efficiency categories. However, their efficiency can vary depending on whether the system uses a single indoor unit or multiple indoor units.
| Efficiency Category | EER | Typical Description |
|---|---|---|
| Below Average | Below 11 | Older fixed-speed equipment |
| Average | 11–13 | Standard single-zone inverter systems |
| Good | 13–15 | Premium single-zone inverter systems |
| Excellent | 15–17 | Highly efficient single-zone systems |
| Multi-Zone Average | 10–12 | Multi-zone systems with 2–5 indoor units |
| Multi-Zone Good | 12–14 | Premium multi-zone systems, depending on connected capacity |
Multi-Zone Mini-Split Efficiency
Multi-zone mini-split systems generally show lower EER values than comparable single-zone systems. This is partly because the outdoor unit must accommodate changing loads among several indoor units and is designed around the total connected capacity rather than the exact load occurring at every indoor unit at the same time.
Consequently, EER values should be compared carefully according to the system configuration and connected capacity.
Portable Air Conditioner EER Chart
Portable air conditioners generally have lower efficiency than central, window, and ductless systems. Exhaust heat, air leakage associated with single-hose configurations, and compressor design all contribute to their comparatively lower efficiency.
| Capacity | Lower Efficiency | Average | Good | Typical Description |
|---|---|---|---|---|
| 8,000 BTU (DOE adjusted) | Below 7 | 7–8.5 | 8.5–10 | Mostly single-hose portable units |
| 10,000 BTU (DOE adjusted) | Below 7 | 7–8 | 8–9.5 | Improved dual-hose designs |
| 12,000–14,000 BTU (DOE adjusted) | Below 6.5 | 6.5–7.5 | 7.5–9 | Larger portable systems |
Important: Portable AC EER Is Not Directly Comparable
The EER of a portable air conditioner should not be directly compared with the EER of a central or window air conditioner.
Portable units must discharge hot air through an exhaust hose. In particular, single-hose models can create negative pressure inside the room, causing warm outside air to enter through openings and gaps. As a result, their practical cooling performance can be considerably less favorable than the rating alone suggests.
Where installation conditions permit, a window AC or ductless mini-split can generally provide a more efficient cooling solution.
EER by Brand: Top Central AC Models
The following table provides examples of high-efficiency central AC models and their listed EER and SEER values:
| Brand | Model | EER | SEER | Technology |
|---|---|---|---|---|
| Lennox | XC25* | 13.5 | Up to 26 | Variable-speed inverter |
| Carrier | Infinity 24 (24VNA4) | 13.0 | 24 | Variable-speed inverter |
| Bryant | Evolution 24 (189CNV) | 13.0 | 24 | Variable-speed inverter |
| Daikin | DX20VC | 13.0 | 20 | Variable-speed inverter |
| Trane | XV20i | 12.5 | 22 | Variable-speed |
| American Standard | Platinum 20 | 12.5 | 22 | Variable-speed |
| Rheem | Prestige RA20 | 12.5 | 20 | Variable-speed |
| Goodman | GVXC20 | 12.0 | 20 | Variable-speed |
| York | YXV | 12.0 | 20 | Variable-speed |
Note: The Lennox XC25 is marketed with a rating of “up to 26.” There is some variation among sources regarding whether this figure represents the legacy SEER rating or the newer SEER2 measurement introduced under the 2023 M1 test procedure. Central AC efficiency ratings can also depend on the specific indoor and outdoor equipment combination. The exact certified rating should therefore be verified for the particular matched system.
Lennox also markets newer variable-capacity flagship systems, including the SL25KCV and SL28XCV.
Understanding EER in Context
An EER chart is useful for comparing equipment, but the EER value should be considered alongside other performance characteristics.
EER and SEER Do Not Improve at the Same Rate
An air conditioner can show a much larger improvement in SEER or SEER2 than in EER or EER2. For example, a system could increase from 16 to 22 SEER2, representing roughly a 38% improvement, while its EER2 may increase from 11 to 13, or approximately 18%.
This difference occurs because SEER primarily reflects performance across varying and part-load operating conditions, while EER focuses more strongly on performance under a specified full-load condition.
Higher EER Usually Means a Higher Purchase Price
Improving EER generally involves more advanced equipment and technology, which can increase the initial purchase price.
For central air-conditioning systems, each additional EER point may add approximately $500–$1,500 to the system cost. For mini-split systems, the additional cost is generally more modest, at approximately $200–$500 per EER point.
EER Can Decline at Higher Outdoor Temperatures
The rated EER is measured under standardized test conditions, including an outdoor temperature of approximately 95°F. When outdoor temperatures rise to 105°F or 115°F, actual operating efficiency generally decreases.
Higher-efficiency equipment tends to retain an efficiency advantage under extreme conditions, although its actual performance will still depend on operating conditions and equipment design.
Key Takeaways
- For a central AC, an EER of approximately 11.5 or higher can generally be considered good.
- For central systems, an EER of approximately 13 or higher falls into the excellent range.
- For window ACs, 11+ CEER is a useful benchmark for good efficiency. ENERGY STAR-qualified models commonly have CEER values of 12.1 or higher, depending on capacity.
- Ductless mini-splits generally enter the good range at around 13 EER, with top single-zone systems reaching approximately 15–17 EER.
- Portable air conditioners typically have the lowest EER values, commonly within the 7–10 range.
- The historical federal tax-credit benchmark was 12.0 EER2, together with 17.5 SEER2, although the 25C credit expired for 2026 installations.
- EER values should be compared within the same type of AC equipment rather than directly comparing a mini-split with a portable AC.
- Larger units within the same equipment category can have lower EER values because of equipment-design and engineering constraints.
- A higher EER generally indicates better full-load cooling efficiency, but the purchase price and expected operating conditions should also be considered.
Conclusion
An EER chart for air conditioners provides a useful way to compare cooling efficiency across different AC types. However, the meaning of a good, average, or excellent EER rating varies between central ACs, window units, ductless mini-splits, and portable air conditioners.
When choosing an AC, consider the EER rating along with EER2, SEER2, cooling capacity, operating conditions, purchase cost, and expected electricity consumption. A higher EER generally indicates better cooling efficiency, but the best choice depends on the equipment type and your specific cooling requirements.
Using the appropriate AC energy efficiency chart can help you identify an efficient system and make a more informed purchasing decision.
Frequently Asked Questions
Mini-splits often have higher EER because they avoid duct losses and commonly use efficient inverter-driven compressors. Central AC systems lose some efficiency through ductwork and larger airflow requirements, so EER values should not always be compared directly.
Generally, yes. A higher EER means more cooling is produced per unit of electricity. However, actual savings also depend on cooling load, operating hours, temperature, thermostat settings, electricity rates, and maintenance.
There is no fixed saving per EER point. Savings depend on system capacity, usage, electricity cost, and operating conditions. For example, under certain assumptions, a 3-ton central AC may save roughly $30–$60 per season for each additional EER point. Actual savings can vary significantly.
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