A while back I was getting cold air coming up from the area of the flap handle. Someone on the forum suggested I check the seal on my door and sure enough the seal was bad causing a vacuum affect drawing the cold air up the flap handle. I purchased a new door seal from Brown's and that solved the problem 99%. Today I was flying with the outside temperature in the 20s. No cold air coming from the flap handle but there was definitely now cold air blowing on the back of our necks. Any idea where I should start looking? Aircraft is a PA 28 140. Thanks.