As the designer of the first intens-o-fire's I highly recommend outdoor air which is denser and has more oxygen to it, to allow for better combustion.
The Hurricane is much like my Intens-O-fires and they add air to the top of the fire to keep the unburnt gases burning much like adding oxygen to actetylene on a torch. The only difference between the 2 is the intens-o-fires have more air injection ports and the grates are different.

Keith, I believe although I could be wrong by the time the air in a bubbler gets to the syrup it will be the same temperature as the syrup. I know that sugarmakers up here that have them have noticed increased evaporation although not big amounts.