I Have A Whirlpool Dryer And It Is Not Drying The Clothes At A Very Fast Rate. I Have To Run A Regular Size Load Through The Cycle Two Times Before They Are Dry. My Vent Is Kind Of Weird, Where My Laundry Room Is The Vent Has To Run Up Through The Roof And I Don't Know If This Has Something To Do With It Or Not. My Vent Tube Coming From The Back Is Relativley Short And Is Not Clogged Up.

See if it is stopped up where it goes into the wall and up to the roof. It is also possibly blocked on the roof if birds can get in the exhaust vent and build a nest. If that fails to solve it just disconnect the vent hose and see if a load dries fine, if it doesn't it might have lint built up in the machine. Also make sure the lint screen is clean.