Many non-brand name portable air conditioners have a lower amperage rating but a higher BTU rating. This doesn't make sense, how could a non-brand name portable air conditioner output 50% more cooling power and use almost the same amount of power as a brand name model?

For example, a LG Model # LP0817WSR portable air conditioner has a BTU rating of 8,000 and pulls 9.2 amps. A Whynter Model # ARC-12S portable air conditioner has a BTU rating of 12,000 and pulls only 9.5 amps.

Is it common for manufacturers to overstate BTUs? Is going by amperage better than going by BTUs?

I currently have the LG model stated above and can get the bedroom down to about 68 F when the central air is set to 78 F on a 100 F day. Would the 12,000 be able to take it down to 61 F? The room is only 140 square feet and has 3 older windows.

  • 4
    The BTU rating is the direct measure of cooling power. The relationship between the BTUs and the power requirement is how efficient it is. The brand name could be a cheap, low efficiency model, and the no-name could be a high efficiency model. That said, a nearly 50% difference sounds suspicious. One possibility: the current is a maximum amount for start-up, not the operating current, or the models aren't advertising the same parameter. Another possibility: a fake spec or typo. Compare all of the values to other units to see which one is a total outlier.
    – fixer1234
    Commented Jun 14, 2017 at 5:29
  • Lot of electrical appliances come with deceptive amperages or wattages printed on the box. Commented Oct 30, 2017 at 22:49

1 Answer 1


Some manufacturers will use outputs based on what we used to call "lab standards", which meant that the figures could only be achieved in a perfect setting or perfectly controlled environment. With these units the testing parameters were controlled perfectly to obtain numbers that were not attainable in normal operating environments. Others use average numbers. If the numbers look to good to be true they probably are. As fixer1234 stated the difference could be a higher efficiency model, but in that case the price difference would be much higher. Sometimes the numbers are just too good to be true.---- And as for being able to get the room to 61 degrees, it is impossible for me to say since at some point as the temperature goes lower the A/C unit will just ice up and stop performing. These units are not made to operate at that temperature.

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