Our two-hundred-year-old house was not originally designed for air conditioning and required major modifications. Our builder recommended we hire A/C Masters Heating & Air Conditioning Inc. for the job. They installed two units. The major unit downstairs is a four-ton eighteen SEER. Upstairs in the house, they installed a highly efficient split system. Both installations went very well. The techs showed up on time and cleaned up behind themselves. I highly recommend A/C Masters Heating & Air Conditioning Inc.