Here I asserted that Angel couldn't do CPR as his breaths are too weak.
However, if there had been a scene of Angel inflating balloons for a children's party, then I'd say my answer was bunk.
I've just had a quick look and I can't find any reference to him blowing one up, but my search wasn't exhaustive.
Does he ever blow one up?
I don't particularly care about taking or normal breathing, I'm interested in the large forceful puffs of air needed to inflate a party balloon.