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ASHRAE BTU vs SACC: why your portable AC feels smaller than the box
Updated
The big number on a portable AC box is the ASHRAE BTU. It is measured as if the unit's own heat and the air it pulls in did not matter. The DOE's SACC number counts both, so it is lower. On the listings here the SACC is 56 to 83 percent of the box number. Buy by the SACC.
What SACC measures
SACC stands for seasonally adjusted cooling capacity. The DOE test for portable air conditioners is set out in federal rule 10 CFR 430, Appendix CC. It defines SACC as the cooling delivered to the room, in BTU per hour. The test measures heat that comes off the exhaust duct and heat carried in by infiltration air, the outside air that gets pulled into the room to replace what the unit blows out.
It also runs the test at two outdoor temperatures and weights them. The rule gives a weighting of 0.2 for the 95 degree F test and 0.8 for the 83 degree F test. So SACC leans toward a typical warm day, not the hottest one.
The DOE page for portable air conditioners says the current efficiency standards were set in a final rule published January 10, 2020, with compliance required from January 10, 2025. Portable listings now often show the SACC number next to the box number. Many still lead with the bigger one.
The gap on real listings
ASHRAE BTU on the boxSACC (DOE) BTU
- Midea Duo 12,000 BTU12,000 BTU10,000 BTU
- Whynter ARC-14S14,000 BTU9,500 BTU
- BLACK+DECKER BPACT14WT14,000 BTU10,200 BTU
- Whynter ARC-122DS12,000 BTU7,000 BTU
- BLACK+DECKER BPACT10WT10,000 BTU5,550 BTU
- Frigidaire FHPC082AC18,000 BTU5,500 BTU
- Midea 8,500 BTU8,500 BTU5,000 BTU
| Model | Box (ASHRAE) | SACC / DOE | SACC as a share of the box |
|---|---|---|---|
| Midea Duo 12,000 BTU | 12,000 | 10,000 | 83% |
| Whynter ARC-14S | 14,000 | 9,500 | 68% |
| BLACK+DECKER BPACT14WT | 14,000 | 10,200 | 73% |
| Whynter ARC-122DS | 12,000 | 7,000 | 58% |
| BLACK+DECKER BPACT10WT | 10,000 | 5,550 | 56% |
| Frigidaire FHPC082AC1 | 8,000 | 5,500 | 69% |
| Midea 8,500 BTU | 8,500 | 5,000 | 59% |
Two things stand out. The dual and hose-in-hose units are not all alike: the Midea Duo keeps 83 percent, while the Whynter ARC-122DS keeps 58 percent. And the BLACK+DECKER BPACT10WT listing shows two lower numbers, 5,550 DOE in the bullets and 6,300 SACC in one spec line. When a listing disagrees with itself, plan on the smaller number.
Where to find the SACC on a listing
- In the title, often in brackets: "12,000 BTU (10,000 BTU SACC)".
- In the spec table, as "BTU SACC", "SACC Rating" or "BTU DOE Rating".
- Some makers now name the model by it. Midea's own support page calls the Duo MAP12S1TBL a "10,000 BTU DOE" unit, while the Amazon title leads with 12,000.
- No SACC or DOE number anywhere? Treat the box number with suspicion. The listing may be older than the rule, or it may be hiding a big gap.
What about the room size on the box?
Room claims usually follow the ASHRAE number, and some go further. The BLACK+DECKER BPACT14WT listing says 700 sq ft. Its 10,200 SACC fits about 450 sq ft on the ENERGY STAR chart. The Midea 8,500 BTU is the exception here. It claims 150 sq ft, and its 5,000 SACC fits exactly that.
Room size the listing claimsRoom the SACC rating fits on the ENERGY STAR chart
- Midea Duo 12,000 BTU450 sq ft450 sq ft
- Whynter ARC-14S500 sq ft400 sq ft
- BLACK+DECKER BPACT14WT700 sq ft450 sq ft
- Whynter ARC-122DS400 sq ft300 sq ft
- BLACK+DECKER BPACT10WT450 sq ft150 sq ft
- Frigidaire FHPC082AC1350 sq ft150 sq ft
- Midea 8,500 BTU150 sq ft150 sq ft
Size your own room with the SACC calculator, or compare all seven picks on the roundup page.