Selecting Air Conditioner Components
In a split system, the compressor and condenser coil (contained in astandardunit or heat pump), are installed outside the home, and the evaporator coil is installed inside the home in the plenum of a forced-air furnace or air handler. The indoor and outdoor components of a split-system are usually connected by two refrigeration lines and a low-voltage relay cable.
The following components make up a split system:
A condensing unit is the main component of central air conditioning, and is the part that sits outside the home. Inside it is a pump called a compressor, coils, fan and electrical system. The condenser comes entirely pre-assembled and pre-charged with Freon.
When a standard air conditioning system (with a condensing unit) is operated, the condenser in the yard gets warm and the evaporator coil in the furnace gets cold, thereby cooling the home in summer.
With a heat pump, the same happens in summer, but in winter, the reverse occurs: the outside condenser gets cold and the inside evaporator coil inside the air handler gets warm, thereby heating the home. Heat pumps are a highly efficient method of heating your home when the outside temperature is above 25 degrees. If you live in an area where the temperature regularly falls below 25 degrees, a secondary heat source such as a gas, oil or propane furnace, or electric resistance heat (heater coils) is required to keep your home warm on the coldest days. Pairing the two heating systems together is called a two-stage heating system (or "hybrid" system), and is commonly done to achieve low operating costs. We will gladly help you select the appropriate two-stage heating equipment for your home.
An evaporator coil is the part of an air conditioning or heat pump system that becomes cold when the unit operates. It is connected to the ductwork of the home. When the system is on, air flows through the coil and the cold air is distributed throughout the home.
Evaporator coils are either cased or uncased and must be matched up with the condensing unit or heat pump to ensure proper operation of your air conditioning system. You will need only one of the following three types:
Cased evaporator coils are used primarily if you are purchasing a new furnace. Cased coils and furnaces sold on our site must be matched up for an exact fit.
Horizontal evaporator coils are used when you have a furnace that is mounted horizontally.
Uncased evaporator coils are used primarily if you already have a furnace and will be inserting the coil in your pre-existing ductwork.
Pads are simply a base for the outdoor air conditioner or heat pump to sit on. They are made of 2-inch thick plastic and are very rigid. The plastic is made with ultraviolet inhibitors so it will not break down in sunlight. Pads come in different sizes, fitted for your particular condensing unit or heat pump.
A disconnect is a safety on/off electrical switch mounted on the home near the condenser or heat pump. It is required by electrical code, and is a good idea for safety and system servicing purposes.
Line sets consist of two semi-flexible copper pipes to connect the outdoor air conditioner or heat pump to the indoor evaporator coil. The smaller pipe is called the liquid line. The larger pipe is referred to as the suction line and includes insulation. The liquid line diameter for all systems is 3/8 inches in diameter. The suction line diameter will be either 3/4, 7/8 or 1 1/8 inches, depending on the size and efficiency of the air conditioner or heat pump. Line sets come in several lengths and are designed to be cut to fit your exact needs.
Alpine Home Air Products Supplies Packages make your air conditioning or heat pump installation easy! They include nearly all the miscellaneous materials needed for the job. If you are using an uncased evaporator coil, choose a supplies package that also contains pre-fabricated sheet metal for a fast and easy coil installation. All supplies packages include our exclusive 1-hour installation instructional video that clearly shows you how to install your own air conditioning system successfully.