McMaster Air replaced our 30 year old central air system including redoing all of the duct work in the attic. They did an excellent job: explained the options up front and how the process would work, came on time and finished the work on schedule. They were able to move the furnace up in to the attic instead of the middle of the hallway where the old one was. Other contractors had told us that our attic was too small to do that. The new system works great-much more quiet and covers the whole house evenly for heating and cooling. Overall very professional.