First question is this- Do you know how to use it?
Second question is, how many levers does it have? 2 or 4?
A decent 4 lever heater (deluxe) or a 2 lever(recirculating) should blast you right out of there on a cold day. But if the levers aren't in the right positions, then you're just movin' air. Here's another spot where an owner's manual would have you way ahead of the game.