When I bought my house, I had central HVAC already installed. I never thought that eventually I would need to put a new furnace or air conditioning unit into my house. After ten years, I had to learn more about air conditioning than I realized I didn’t know. I called the HVAC company and they confirmed that I needed a new air conditioning unit. They asked me if I knew what size I needed and I showed them the pad the old AC unit was sitting on. He explained to me that air conditioning units were sized to fit the home it was being installed into. He told me that you needed to have a certain tonnage, which is the power the AC unit gives out. If the tonnage is too small, the AC unit will run continually. You will never be able to get the desired temperature and your energy bills will be extremely high. Getting an air conditioning unit that has too much tonnage, will cause the AC unit to continually cycle. This will also cause the energy bill to skyrocket and it can do damage to the AC unit. The Ac unit will quickly cool your house, but the cool will be so quick that the AC unit won’t be able to take the humidity from the air. I told him to do the measuring that he needed to do and I answered all of his questions. He determined the size air conditioning unit I needed for the house and asked me if I had a special model. I told him to install whatever he thought was best and what would save us the most amount of money.