The cost to replace your central air conditioning unit will vary based on several factors: - The size of your new AC system - The square footage of your home - SEER of your new HVAC system - Your comfort goals At Dunn’s Heating, Cooling, Plumbing, and Electrical, your comfort is our #1 concern along with staying within your budget. This is why we offer free system replacement estimates so you have a clear picture of what your new air conditioning system will cost upfront.