Methanol is a fuel....the extra air required is provided by the tune. Methanol also is an excellent cooler when injected, and most kits run 50/50 methanol and water mix.
On our Alky drag motors the metanol fuel we use (100%) cools extremely well also, Infact just touch a running alky dragsters intake manifold and it will be cool to the touch. It also requires appx 3 times the amount VS gasoline.
Nitrous Oxide is an oxygenator and a power adder (it carries far more qxygen the air alone so it allows for more fuel thus more power).
If you want economical cool IAT temps all the time w/out having to stop and refill a methanol tank every few miles this is the only solution: