26K BTU totally.
If all on, it will be: 7k-7k-6k-6k (BTU)
The sales man informed 485BTU per sqare meter is good enough. Study room is about 18sqm, 18*485=8730, a bit less.
If not all on at the same time, this model has two compressors, which can provide 14K and 12K for one single room...