Airconditioner cool,not cold. How many cans of coolant will it take to recharge? on 1999 Infiniti I30

I have this problem every time I turn on the air conditioner. Have put in 2 cans of coolant & it is cooler but still not cold.

Asked by for the 1999 Infiniti I30
you need to have gauges to fill properly. if you overcharge it will blow hotter also. seek help