What is a "Split System" Air Conditioner? A traditional home comfort system has two parts: an indoor unit, such as a furnace or air handler, and an outdoor unit. An air conditioner is the outdoor unit that cools air and sends it to the indoor unit to be circulated through your home. The indoor and outdoor units are designed to work together, and when the air conditioner is properly matched with a furnace or air handler, the result is maximum efficiency and extended system life. Air conditioning and cooling efficiency is measured using a Seasonal Energy Efficiency Ratio (SEER). A higher SEER signifies higher energy efficiency. Central Air Conditioning A home's "split system" central air conditioning system includes a compressor, a fan, condenser coil, evaporator coil and a refrigerant. It extracts heat from indoor air and transfers it outside, leaving the cooled indoor air to be re-circulated. The efficiency of central air conditioning systems is rated using SEER ratios. A central air conditioning system uses electricity as its power source. The basic components of an air conditioning system are: A Condensing Unit (the outdoor section) A matching indoor Air Handler or Furnace with coil Ductwork to transfer the cooled air throughout the home York offers a wide variety of central air conditioners in different styles, sizes and efficiencies.