I second the recommendation of James Wheat and Sons. I had them in to correct a code violation with my heating system (furnace return duct actually in the furnace room) and to shore up my attic’s shodding duct-work prior to blowing-in insulation. The were the 8th contractor I called. Many didn’t want the job, some never responded, and two tried to pull a bait-and-switch on the scope of the work. James Wheat got the job done, and our house now has much better temperature regulation as a result.