Student or Learner
Let's say the A.C. works perfectly well when there are, let's say, four people in my living room, and it's the right one for the size of the room. But sometimes I get some friends together, and I notice the temperature is not the ideal one, and we begin to sweat. I've learned it's right to say the A.C. is not cooling efficiently. Are there more common and natural ways to say this? I'm asking this question because there is a specific expression in Portuguese that fits the situation.
It's not a question of efficiency, it's a question of capacity. You need a bigger unit (more BTUs of cooling capacity) if you are expecting it to work with a bunch of people in your place.
As it's a capacity issue, I would say that the AC isn't powerful enough.