No a hair drier is not designed to reach the same temperature as a heat gun or proper reflow oven regardless of wattage, a heat gun is designed to strip paint and so will melt solder but at best you might get it working for a little longer but really if you cant do it properly yourself I would recommend finding someone in your local area who has the right equipment. I found someone here in ireland who stripped it down and reflowed and reassembled for 50euro, worked fine after that. There is no point ruining a good ps3 for the sake of 50euro.
I had someone bring a YLOD ps3 to me before for fixing, I told them to get it done professionally as I didnt have right equipment, I seen him again after that and the case was half melted on his ps3, he had put thew whole ps3 into his oven to try and fix it but without stripping it down and just heating the motherboard! What a tool!
FYI : A lower temperature for a longer time is not equal to a higher temperature for a shorter time . ie , A kettle will never boil at 50 degrees no matter how long you heat it for. in the same way the solder will never reflow.