My 1.5HP aircon take ages to get cool, abt 10 minutes, is this normal?

Mitshubishi only takes 5 minutes and the cool air started after the compressor running but NOT for Panasonic. This Econavi is really slow and I was told should be 3-5 minutes. Even after 10 minutes, it only start has some cool air and not really cool as compare with Mitshubishi. That's why I wonder if something wrong with this model. I had old model without Econavi and it works well.