Air Conditioning and Budgie / Parakeet
If your room is hot, use air conditioning.Think of it this way. What if the normal temperature was 110F? Your parakeets would roast. Air conditioning does its job to make a comfortable temperature that is better for healthy living. That's why we humans use it. Sometimes fans just can't help.
That being said, be sure to not direct the air stream at them. You want the parakeets in a comfortable, stable environment.
If you are worried about the gas in the AC unit, that never gets out. It's only regular air that comes out - it is cooled by touching cooled items inside the unit. Also, hospitals are cooled by AC so I think if there was ever a serious risk to babies and elderly and such that it's long since been addressed.
So, to summarize, it's far more important to keep your keets from overheating than to worry about any risk of the gas within the air conditioner harming a parakeet.
All About Parakeet and Budgie Cages
Cat / Parakeet Info Homepage