This picture from Centerville, VA shows a very common problem in our area. Piping is run from the basement all the way up through the house to the attic. The space around this pipe is seldom sealed, allowing cold, outdoor air in the winter and hot, humid outdoor air in the summer to travel unrestricted from the attic, through the house, into the basement. As it passes through this space it's directly behind the unisulated drywall in the middle of the house. Typically, the pipe is run in the same large chase as duct work in homes with only one heating and air conditioning system. That's the same as having 128 square feet of your outside wall uninsulated! It can also result in the formation of mold in the chase or in other areas of the home.
These holes need to be identified and sealed to minimize the problem, resulting in a more comfortable, safer and more efficient home for you and your family.