yes, I echo Marjorie, it should give more energy. Find out how long the 'ramp up" is set for, as the more gradual, the easier it is to accustom oneself to. He can keep hitting the ramp button as many times as he needs to. it does not have to be a one time thing.
Maybe the pressure for his exhale is set too high. If it is, he may be having more co2 build up, rather than getting rid of it, and that would explain why he feels that way. is he having headaches? Does he complain of his ears clogging or getting air down in his esophagus?
Keep at them to get it set correctly for him. Also, its ok if he tries if for a few hours each night and then takes it off. I was told that the goal in the beginning is to be able to wear it for 5 hours a night.