Keystone: 12 DOE certified models
Keystone has 12 basic models certified to DOE as of 2026-11-03: 4 portable ACs (5,000 to 12,000 BTU/h SACC), 1 window AC (8,000 BTU/h) and 7 dehumidifiers (22.31 to 49.74 pints/day under the 2019 DOE test). How their efficiency compares with their DOE class is below.
Key findings
- Highest certified cooling capacity among its portable ACs: Keystone KSTAP121HINV and Keystone KSTAP12PINV tie at 12,000 BTU/h SACC.
- Most efficient for its class: Keystone KSTAP10PINV, CEER 14.7, higher than 327 of the 334 dual hose portable ACs certified to DOE.
- Highest certified water removal among its dehumidifiers: Keystone KSTAD504G and Keystone KSTAD506PG tie at 49.74 pints/day.
Source: DOE Compliance Certification Database (portable ACs, window ACs, dehumidifiers), data as of 2026-11-03.
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Portable air conditioners
| # | Photo | Model | Labels | SACC, BTU/h | Covers | CEER | Hose | Heat | Brands | Amazon |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 |  | KeystoneKSTAP121HINV |
| 12,000SACC, up to 550 sq ft | 550 sq ft | 14.2 | Dual hose | Yes | 1 | Check price on Amazon |
| 2 | | KeystoneKSTAP12PINV |
| 12,000SACC, up to 550 sq ft | 550 sq ft | 13.8 | Dual hose | No | 1 | Check price on Amazon |
| 3 | | KeystoneKSTAP10PINV |
| 10,000SACC, up to 450 sq ft | 450 sq ft | 14.7 | Dual hose | No | 1 | Check price on Amazon |
| 4 |  | KeystoneKSTAP051PA |
| 5,000SACC, up to 150 sq ft | 150 sq ft | 6.1 | Single hose | No | 1 | Check price on Amazon |
Window and room air conditioners
| # | Photo | Model | Labels | Cooling, BTU/h | Covers | CEER | Watts | Type | Heat pump | Brands | Amazon |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 |  | KeystoneKSTAW08INV- |
| 8,000BTU/h, up to 350 sq ft | 350 sq ft | 14.5 | 700 | Window | Yes | 1 | Check price on Amazon |
Dehumidifiers
| # | Photo | Model | Labels | Pints/day (2019 test) | IEF, L/kWh | DOE class | Brands | Amazon |
|---|---|---|---|---|---|---|---|---|
| 1 |  | KeystoneKSTAD504G |
| 49.74pints/day, 2019 DOE test | 2.01 | 25 to 50 | 1 | Check price on Amazon |
| 2 | | KeystoneKSTAD506PG |
| 49.74pints/day, 2019 DOE test | 2.01 | 25 to 50 | 1 | Check price on Amazon |
| 3 |  | KeystoneKSTAD504F |
| 49.66pints/day, 2019 DOE test | 1.9 | 25 to 50 | 1 | Check price on Amazon |
| 4 | | KeystoneKSTAD506PF |
| 49.66pints/day, 2019 DOE test | 1.9 | 25 to 50 | 1 | Check price on Amazon |
| 5 | | KeystoneKSTAD354G |
| 36.71pints/day, 2019 DOE test | 2.01 | 25 to 50 | 1 | Check price on Amazon |
| 6 | | KeystoneKSTAD224F |
| 22.31pints/day, 2019 DOE test | 1.7 | up to 25 | 1 | Check price on Amazon |
| 7 | KeystoneKSTAD354F |
| 35.5pints/day, 2019 DOE test | 1.9 | 25 to 50 | 1 |
How efficient are Keystone models?
Portable air conditioners
Of the 4 Keystone portable ACs, 3 file a higher CEER than the class median and 1 falls below it.
| Class | Keystone models | Above median | Class median | Best Keystone |
|---|---|---|---|---|
| Dual hose portable ACs (334) | 3 | 3 | CEER 12.5 | KSTAP10PINV CEER 14.7 |
| Single hose portable ACs (1,044) | 1 | 0 | CEER 7.3 | KSTAP051PA CEER 6.1 |
Window and room air conditioners
Keystone KSTAW08INV-HC files CEER 14.5 Btu/Wh. The median among the 19 models in its DOE class (window ACs with heat pump, less than 20,000 BTU/h) is 15.1, so it's below the median: higher than 3 of the 19.
Dehumidifiers
Of the 7 Keystone dehumidifiers, 3 file a higher IEF than the class median, 1 matches it and 3 fall below it.
| DOE class | Keystone models | Above median | Class median | Best Keystone |
|---|---|---|---|---|
| Portable dehumidifiers, 25 to 50 pints/day (296) | 6 | 3 | IEF 1.91 | KSTAD354G IEF 2.01 |
| Portable dehumidifiers up to 25 pints/day (253) | 1 | 0 | IEF 1.7 | KSTAD224F IEF 1.7 |
A higher CEER means more cooling per watt. A higher IEF means more water removed per kWh.
Who makes Keystone portable ACs, window ACs and dehumidifiers?
DOE's database has no manufacturer field, so the evidence is whose model number each unit is filed under and which other brands file the same unit.
None of the 12 Keystone basic models is filed by another brand as of 2026-11-03, and none uses another company's model number. DOE's records tie them to Keystone alone.
How much do Keystone models cost to run?
While cooling, Keystone portable ACs draw about 680 to 870 W (certified SACC divided by CEER). That's 12¢ to 16¢ an hour, or $29.65 to $37.90 for 30 days at 8 hours a day. The lowest is Keystone KSTAP10PINV (10,000 BTU/h SACC, CEER 14.7) and the highest Keystone KSTAP12PINV (12,000 BTU/h SACC, CEER 13.8).
For Keystone KSTAW08INV-HC, DOE's record lists 700 W of electrical input while cooling. That's about 13¢ an hour ($30.51 for 30 days at 8 hours a day).
Running nonstop at DOE's test conditions, the 7 Keystone dehumidifiers with both figures use 6.21 to 12.37 kWh a day. That's about $1.13 to $2.25 a day, or $33.83 to $67.38 for 30 days. The lowest is Keystone KSTAD224F (22.31 pints/day, IEF 1.7) and the highest Keystone KSTAD504F (49.66 pints/day, IEF 1.9).
Real use cycles on and off with the humidity, so the dehumidifier figures are the upper end for a day of nonstop running.
At 18.16¢ per kWh, the US average residential price for August 2026 (EIA Electric Power Monthly, table 5.6.A). Worked out from the certified figures.
Questions about Keystone
- Is Keystone a good dehumidifier brand?
- How its 7 dehumidifiers compare on efficiency with their DOE class is above. All 7 are filed under Keystone alone. We don't test reliability, noise or build quality, so we can't rank brands on those. How we compare models.
- Does Keystone make a 50 pint dehumidifier?
- Yes, by the 2019 DOE test: 4 of its models certify 49.5 pints/day or more, led by Keystone KSTAD504G at 49.74 pints/day. By DOE class: 1 in the up to 25 pints/day class and 6 in the 25 to 50 pints/day class. How the 2019 test changed pint ratings.
- Which Keystone dehumidifier is the most efficient for its size?
- Keystone KSTAD354G, Keystone KSTAD504G and Keystone KSTAD506PG tie at IEF 2.01: higher than 161 of the 296 in its DOE class (portable dehumidifiers, 25 to 50 pints/day). At the other end are Keystone KSTAD354F, Keystone KSTAD504F and Keystone KSTAD506PF, at IEF 1.9, higher than 60 of the 296 in its class.