Shedding

My 5 year old male chin, Chubbs, has been shedding more than usual lately. It is summer here, but it's consistently 69 F here in my house. Last night he was enjoying a pat, not at all distressed, and lost a fair chunk of fur. It didn't leave a bald spot so I feel it is more normal shedding than distress sloughing. I've read that brushing is bad and combing is not necessary and often very uncomfortable for the chin.

Is heavy shedding normal sometimes? Do you recommend combing or something else?