Central air conditioning is a common term used to describe most whole-home air conditioning systems. It replaces warm air with cold air that has passed through cold coils and then pushes it into living spaces. There are two different types of central air conditioners, split systems and packaged systems. In the air conditioning industry, the term HVAC is often used instead of AC.
HVAC stands for Heating, Ventilation, and Air Conditioning, while AC simply refers to air conditioning. Air conditioning is generally used when referring to systems that are designed to cool the air in your home. Window units and central air conditioning are standard systems that are widely used. Air conditioning can include heat pumps and gas furnaces, as well as air conditioning units. This means that HVAC takes care of both heating and cooling.
Air conditioners dehumidify the air to improve comfort. However, in extremely humid climates, when outdoor temperatures are moderate, or when the air conditioner is too large, the air may not reach a humidity low enough to reach a comfortable level. In those cases, homeowners can lower the thermostat settings or use a dehumidifier. But in both cases, this will increase energy use, both for the dehumidifier itself and because the air conditioner will require more energy to cool the house. If you have a central air system in your home, set the fan to automatic mode.
In other words, don't use the system's central fan to provide air circulation; use circulating fans in individual rooms. A central air conditioner is a split system unit or a packaged unit. In a split-system central air conditioner, an outdoor cabinet contains the outdoor heat exchanger, the fan and the compressor, and an indoor cabinet contains the indoor heat exchanger and the fan. In many split-system air conditioners, the indoor cabinet can contain an oven or the indoor heat exchanger of a heat pump. If your home already has an oven but doesn't have air conditioning, a split system may be the most economical central air conditioner to install.
In a packaged central air conditioner, the heat exchangers, compressor, fan, and fan are all located in a cabinet, which is usually placed on a roof or concrete slab next to the foundation of the house. This type of air conditioner is also used in small commercial buildings. The supply and return ducts come from the inside through the outer wall or roof of the house to connect to the packaged air conditioner. Packaged air conditioners often include electric heating coils or a natural gas furnace.
This combination of air conditioning and central heater eliminates the need for a separate oven. If your air conditioner is installed correctly or if major installation problems are found and fixed, it should operate efficiently for years with only minor routine maintenance. However, many air conditioners are not properly installed. As an unfortunate result, modern, energy-efficient air conditioners can perform almost as poorly as older, inefficient models.
Central air conditioners are more efficient than room air conditioners. In addition, they are discreet, quiet and comfortable to operate. To save energy and money, you should try to purchase an energy efficient air conditioner and reduce the energy use of the central air conditioner. In an average-sized home, air conditioning consumes more than 2,000 kilowatt-hours of electricity per year, causing power plants to emit about 3,500 pounds of carbon dioxide and 31 pounds of sulfur dioxide.
If you're considering adding central air conditioning to your home, the deciding factor may be the need for a duct network. The most efficient air conditioners use 30 to 50% less energy to produce the same amount of refrigeration as those manufactured in the mid-1970s. Even if your AC unit is only 10 years old, you can save 20 to 40% of your cooling energy costs if you replace it with a newer model that is more efficient. Proper sizing and installation are key elements in determining how efficient your AC will be.
A unit that is too large will not properly remove moisture from your home's atmosphere while one that is too small will not be able to reach a comfortable temperature on hot days. Incorrect unit location, lack of insulation, and improper duct installation can also greatly decrease efficiency. The regulations don't require you to change your existing central AC units; replacement parts and services should continue to be available for your home systems. The lifespan of a central AC unit is about 15 to 20 years.
Manufacturers often continue to support existing equipment by making spare parts available and fulfilling maintenance contracts once new standards take effect. Sign up for Energy Saver updates including new blogs, updated content and seasonal energy savings tips for consumers and homeowners.
