Data through April 2026
Running cost · Room Air Conditioners · ENERGY STAR certified
Keystone KSTAW12INV
The Keystone KSTAW12INV is certified at 600 kWh per year (based on 750 standardized hours), roughly $113 at the national average — though seasonal use means your real bill lands in a few months, not twelve. That's close to the middle of the certified pack — about 13% above the median room air conditioner, ranked 247 of 396. The same unit costs $74 a year in North Dakota but $280 in Hawaii — electricity rates, not the appliance, make the difference.
Estimated annual running cost · U.S. average rate 18.8¢/kWh
$113/yr
- Per month
- $9.41
- Per day
- 31¢
- Certified use
- 600 kWh/yr
- Cooling capacity
- 12,000 BTU/hr
- CEER
- 15
- Mounting
- Straddles Window
- Variable-speed compressor
- Yes
What it costs in every state
| State | Rate ¢/kWh | This model $/yr | Relative cost |
|---|---|---|---|
| Alabama | 17.4¢ | $104 | |
| Alaska | 27.4¢ | $164 | |
| Arizona | 15.5¢ | $93 | |
| Arkansas | 14.2¢ | $85 | |
| California | 35.3¢ | $212 | |
| Colorado | 16.5¢ | $99 | |
| Connecticut | 32.2¢ | $193 | |
| Delaware | 18.8¢ | $113 | |
| District of Columbia | 25.4¢ | $152 | |
| Florida | 15.4¢ | $92 | |
| Georgia | 15.4¢ | $92 | |
| Hawaiipriciest | 46.6¢ | $280 | |
| Idaho | 12.7¢ | $76 | |
| Illinois | 20.5¢ | $123 | |
| Indiana | 17.9¢ | $107 | |
| Iowa | 13.9¢ | $83 | |
| Kansas | 15.8¢ | $95 | |
| Kentucky | 15.0¢ | $90 | |
| Louisiana | 14.4¢ | $87 | |
| Maine | 28.4¢ | $171 | |
| Maryland | 22.1¢ | $132 | |
| Massachusetts | 29.4¢ | $177 | |
| Michigan | 21.4¢ | $128 | |
| Minnesota | 16.4¢ | $98 | |
| Mississippi | 16.8¢ | $101 | |
| Missouri | 14.0¢ | $84 | |
| Montana | 13.9¢ | $83 | |
| Nebraska | 13.3¢ | $80 | |
| Nevada | 14.3¢ | $86 | |
| New Hampshire | 27.2¢ | $163 | |
| New Jersey | 23.5¢ | $141 | |
| New Mexico | 15.2¢ | $91 | |
| New York | 29.4¢ | $177 | |
| North Carolina | 16.3¢ | $98 | |
| North Dakotacheapest | 12.3¢ | $74 | |
| Ohio | 19.5¢ | $117 | |
| Oklahoma | 13.3¢ | $80 | |
| Oregon | 15.8¢ | $95 | |
| Pennsylvania | 21.5¢ | $129 | |
| Rhode Island | 28.3¢ | $170 | |
| South Carolina | 17.1¢ | $102 | |
| South Dakota | 14.5¢ | $87 | |
| Tennessee | 14.9¢ | $90 | |
| Texas | 17.0¢ | $102 | |
| Utah | 13.3¢ | $80 | |
| Vermont | 24.6¢ | $147 | |
| Virginia | 17.4¢ | $104 | |
| Washington | 14.4¢ | $86 | |
| West Virginia | 16.1¢ | $96 | |
| Wisconsin | 19.2¢ | $115 | |
| Wyoming | 14.7¢ | $88 |
Certified models closest in efficiency
| Model | kWh/yr | $/yr (US avg) |
|---|---|---|
| BLACK+DECKER BD12NWES | 600 | $113 |
| Century RXTS-121A | 600 | $113 |
| Comfort Aire RXTS-121A | 600 | $113 |
| Danby DAC120ECBIWDB | 600 | $113 |
| DELLA 048-TL-W12KI | 600 | $113 |
| ELEMENT EHWR12BE | 600 | $113 |
Run your own numbers
Your rate, your numbers
- Per day
- 31¢
- Per month
- $9.41
- Per year
- $113
600 kWh/yr × 18.8¢/kWh = $113/yr
Prefilled with this model's certified 600 kWh/yr — adjust if your usage differs from the DOE test basis. The certified annual kWh assumes 750 cooling hours per year (the DOE standard). In hot climates real usage can run well above that; in mild ones, below.
Questions, answered with the data
- How much electricity does the Keystone KSTAW12INV use?
- ENERGY STAR certifies the Keystone KSTAW12INV at 600 kWh per year. The certified annual kWh assumes 750 cooling hours per year (the DOE standard). In hot climates real usage can run well above that; in mild ones, below.
- How much does the Keystone KSTAW12INV cost to run per month?
- About $9.41 a month at the U.S. average residential rate (18.8¢/kWh) — 31¢ a day, or $113 a year. Your state's rate moves this up or down; see the table above.
- Is the Keystone KSTAW12INV energy efficient?
- It uses 13% more electricity than the median certified room air conditioner.
- What does the Keystone KSTAW12INV cost to run in the cheapest vs. priciest state?
- At current residential rates it costs about $74 a year in North Dakota (12.3¢/kWh) and $280 in Hawaii (46.6¢/kWh).