What is the difference between BTU and BTU DOE on a portable air conditioner?

Answered by RV Parts Giant · Upland, CA · November 1, 2026

Short answer: They are two ratings of one machine. The headline number is the higher one, and the DOE number is lower: an 8,000 BTU unit in our range is 5,000 BTU DOE. Compare portable ACs DOE against DOE, because there is no fixed conversion and the square-foot claims do not line up between brands.

Westinghouse spells it out on its listings: "Rated 8,000 BTU ASHRAE (5,000 BTU DOE)." The two numbers come from two different test standards. Many brands put the bigger one in the product title, so two units with the same headline can cool quite differently.

What our listings state

Portable AC	Headline BTU	DOE BTU	Listed area
AIRO COMFORT 8,000	8,000	5,000	350 sq ft
Westinghouse WPac8000s	8,000 ASHRAE	5,000	350 sq ft
Frigidaire FHPC082AC1	none given	5,500	150 sq ft
AIRO COMFORT 10,000	10,000	6,000	450 sq ft
Frigidaire FHPC102AC1	none given	6,500	250 sq ft
AIRO COMFORT 12,000	12,000	8,000	550 sq ft
AIRO COMFORT 14,000	14,000	10,000	700 sq ft
Westinghouse WPac14000h	14,000 ASHRAE	8,150	700 sq ft
LG LP1419IVSM	none given	10,000	450 sq ft
Whynter ARC-14S	9,500	not listed	500 sq ft

Three things the table shows

You cannot convert one number to the other. The two 14,000 BTU units are 10,000 and 8,150 BTU DOE. That is a gap of 1,850 BTU DOE behind an identical headline.

The higher DOE number can come with the smaller area claim. The Frigidaire is 5,500 BTU DOE and lists 150 sq ft. The AIRO and the Westinghouse are 5,000 BTU DOE and list 350 sq ft. At 10,000 BTU DOE, the AIRO lists 700 sq ft and the LG lists 450 sq ft. Those area figures are not a shared yardstick, so don't rank units on them.

Some listings give only one number. The Whynter lists 9,500 BTU with no DOE figure, so it cannot be placed on this comparison from the listing alone. Check the spec sheet in the manual, or ask us.

What to do with it

Compare DOE to DOE when both units publish it.
Size for your actual enclosed space with our portable AC sizing guide, not the household area on the box.
Check the power draw on the unit's label before you plan on a generator or pedestal. These listings do not state watts, and the BTU rating does not tell you.