New to woodburning need help. My husband installed a godin petit 3720. He used dura vent double wall chimney kit 6" straight thru ceiling (with attic space) When he burns the wood there is an almost chemical smell which causes my eyes and nose to burn and feel nausea, and get a headache. the wood is seasoned and untreated, our house is sealed too well so we do crack a window nearby, any help would be appreciated.