Around 80% of new homes built in the United States are equipped with a central air conditioning unit. In addition, many homeowners are installing central a/c in older homes, or replacing their older air conditioning units. As a result, the prevalence and sales of central air conditioning systems is very high. Why is Central Air So Popular? Central air conditioning is the most efficient way to get cool air flow to multiple rooms in a home. Window-mounted units are economical when the intent is to cool a single small space or room, but when looking to cool an entire home, central air conditioning is the most feasible.  Central air is also quieter than window mounted air conditioners. Different Types to Consider When installing a central a/c system, the entire unit can be installed outside the home, or it can be a split device where the condenser and compressor are installed outdoors and the evaporator or blower is located inside on the furnace. The latter is the most economical.

With this configuration, the furnace’s blower delivers the cooled air to your rooms through the furnace’s air duct system. If a home doesn’t have ducts, a separate blower can be installed to distribute the cooled air. Proper “Sizing” is Critical When determining the size of air conditioner your home requires, remember that bigger is not always better. data center air handling unitIn fact, an air conditioner that is too big or too small can use excessive amounts of energy, run loudly and break down prematurely. prices for hvac systemsFactors of your home that need to be taken into account to properly “size” your air conditioner include:cost of split air conditioner installation Quality of insulation and air sealing

Window size, number, type and direction Beware of Sizing by Rule of Thumb Sizing of your air conditioner should be done by an experienced professional.  Proper sizing requires taking several measurements in the home which are used, along with the features listed above, to determine the appropriate size needed. Beware of any contractor who uses a simple rule of thumb such as square footage to determine the size. Find a RESNET Qualified ENERGYSMART Contractor. Start With an Energy Audit Before installing an air conditioning system, it is a good idea to have a home energy audit to assess the quality of your insulation and air sealing, and to test your ductwork for leaks. By taking remedial actions you will save energy by making your home more energy efficient, and potentially save even more money by requiring a smaller, less expensive air conditioning system. Find a RESNET Certified Energy AuditorAn air conditioning system keep inhabitants cool during hot summer months and directly affects the value of the home and its contents.

Modern construction methods incorporate both heating and cooling into packaged systems that include total temperature and air quality conditioning. The conditioned square footage of the home directly affects its value. These systems are among the largest investments owners make in their home, so it is important for owners to be familiar with a few of the fundamental principles involved. For homes that already have a furnace, it is often more economical to purchase a split system, according to Energy.gov. This adds a condenser/compressor unit that sits outside, and an evaporator unit that ties into the furnace and utilizes the existing heating ductwork and thermostat. This reduces the homeowner's initial cost of the upgrade, savings that can be used to further increase efficiency by adding a programmable thermostat and insulating ducts to improve cold air distribution. Due to strides made in energy efficiency, as well as the deterioration of efficiency in old units, some owners may choose to replace the entire heating and cooling system with a packaged system.

This also provides more efficient heating for those who wish to upgrade from fuel oil furnaces or other outdated heating systems, while adding the central air conditioning desired. In packaged systems, the evaporator, condenser, compressor, and heat pump reside in one outdoor location. Making the investment in a packaged system can provide year-round energy savings and increased comfort for homeowners. Outdoor environmental elements cause condensing units to deteriorate and become inefficient. Many homeowners chose to upgrade only the condensing unit with a high efficiency model, particularly when the indoor evaporator coil is still serviceable. When replacing only the condensing unit, it is important to ensure that the new unit matches the size and capacity of the remaining indoor evaporator unit. Proper sizing is essential. Engineers measure air conditioning capacity in British thermal units per hour, or "Btu/hr." For central air systems, engineers convert these to "tons" equal to 12,000 Btu/hr.

Tonnage for average homes ranges from 1 to 5 tons, calculated on square footage. However, more tonnage does not result in better performance. Because of their high output, oversized units cycle on and off more frequently, increasing energy demand. They do not stay on long enough to circulate the air in the home, decreasing air filtering and dehumidification. With frequent stops and starts, these units are also subject to increased breakdowns. Regional climate conditions require adjustments to any rule of thumb for sizing units, as do specific home site conditions. Extremely shady or sunny sites require an allowance of up to 10 percent. The number of people and pets occupying the premises also necessitate further adjustment. Whether purchasing new or used air conditioning equipment, homeowners should opt for energy efficient units, according to EnergyStar.gov. When purchasing overstock or used models, homeowners should check the SEER (Seasonal Energy Efficiency Rating) and inform themselves of current minimum requirements at the time of purchase.

SEER ratings refer to energy efficiency during the cooling season. For units that contain a heat pump, owners should also check the Heating Seasonal Performance Factor (HSPF). Homeowners who wish to cut costs can discuss direct sourcing with their contractor. Many work with an owner who can purchase the materials directly, and perform custom load calculations that accurately provide the specifications for purchasing new equipment. Installing a new air conditioning system requires a variety of skills, including electrical, plumbing, and even programming skills. An experienced local contractor is familiar with requirements for inspection or permitting. Other tasks, such as adding programmable thermostats, insulating ductwork, or pouring the concrete slab may be more suitable for the do-it-yourselfers. Homeowners should contact several reputable contractors in their area for estimates. There is a wide inventory of home air conditioning equipment available from the sellers on eBay.