you should take your project on parts.You can conect a 5v relay(i have some from ebay) if you will not exeed 1000w,in their datasheet those relay handless up to 10Amps AC(but i''m not that shore),so with the formula Amp x V = Watts,theoreticly it should handle 2200W...now u cannot conect a big fan,like u want....for that u need to conect a second relay to the first relay(like a biger one 12V)
As for the fan regulator the easyest way i think is a servo....Bluetooth is great for that but is a lot of coding.Good luck Niner