Back a while I recall seeing a related thread. Please forgive me if this has already been mentioned but it`s worth seeing again and a quick visit to this link below will bring to light a significantly important reason to install an OAK .
http://www.askthebuilder.com/B103_H...perature_Indoor-Outdoor_Humidity_Tables.shtml
http://www.askthebuilder.com/B103_H...perature_Indoor-Outdoor_Humidity_Tables.shtml