Central Air Conditioner Units

central-air-conditioner-units3Central air conditioners have two separate components: the condenser and the evaporator. The condenser unit is installed outdoors and the evaporator coil is mounted in the plenum or main duct junction above the furnace. Most central units are connected to a home forced-air distribution system. The operating principle of central system consists in the feed of indoor hot air to the furnace through the return-air duct, then hot air is moved by the blower across the cooled evaporator coil in the plenum and in the end delivered through ducts to cool the house.

There are different types of central air conditioners and they are: split-system and packaged central air conditioners. In a split-system appliance, an outdoor metal cabinet contains the condenser and compressor, and an indoor cabinet contains the evaporator. In many split-system units, this indoor cabinet also contains a furnace or the indoor part of a heat pump. The air conditioner's evaporator coil is installed in the cabinet or main supply duct of this furnace or heat pump. If your home already has a furnace but no air conditioner, a split-system is the most economical central appliance to install.

central-air-conditioner-units2In a packaged central air conditioner, the evaporator, condenser and compressor are located in one cabinet and it is usually installed on a roof or on a concrete slab next to the house's foundation. This type of appliances is also used in small commercial buildings. Air supply and return ducts come from indoors through the home's exterior wall or roof to connect with the packaged air conditioner, which is usually fixed outdoors. Packaged units often include electric heating coils or a natural gas furnace. This combination of air conditioner and central heater eliminates the need of a separate furnace indoors.

Central air conditioners are more efficient, than room ones. In addition, they are out-of-the-way, quiet and convenient to operate. Choosing an air conditioner, look for a model with high efficiency. Central systems are rated according to their seasonal energy efficiency ratio (SEER). SEER indicates the relative amount of energy, needed to provide a specific cooling output. A lot of older systems have SEER ratings of 6 or less. The minimum SEER allowed today is 10. Look for the ENERGY STAR label for central appliances with SEER ratings of 10 and higher. In this case you will get efficient energy-saving operation. But, keep in mind, that this type of air conditioners is rather expensive. The installation is complicated and it has to be done by a professional. But central system is reliable and durable, so it is installed for broad term use.