Central Air Conditioner Cost

• Adding central air conditioning to an existing forced-air heating system in a 2,000-square-foot house averages $3,500 -$4,000, and can be done by two technicians in 2-3 days, with little or no change to the existing ducting; if ducts must be added, the work time doubles, as does the cost to $7,000 -$8,000 or more, according to ThisOldHouse.com.
• Estimates for a older, smaller house of 800-1,000 square feet with no existing duct work run $2,100 -$6,000, or as high as $10,000 or more, depending on the type and quality of equipment installed, the amount of space available for installing ducts and vents, and the local economy.

• The Air-Conditioning and Refrigeration Institute provides a brief explanation of how central air conditioning works. The California Consumer Energy Center offers detailed information on central air systems and specifics on ducts and vents.
• Most central air conditioning systems are a split system, with the heaviest, noisiest, heat-generating components installed outdoors, and an evaporator coil indoors. The evaporator is connected to a blower (often part of a furnace) which distributes the chilled air through the home's vents. ThisOldHouse.com gives an overview. The other option is called a packaged central air conditioner; the condenser, compressor and evaporator are all in a cabinet which is installed on the roof or next to the house.
• HVAC is a common industry term; it stands for heating, ventilation and air conditioning. A HVAC contractor does what's called a load calculation, taking into account the size and shape of the house, the amount of insulation, the local climate, the house's exposure to the sun, the occupants' habits and temperature choices, and other factors to determine what size unit is needed.
• If an air conditioner is too large for the space, the unit will cycle off and on frequently, creating uncomfortable temperature swings and reducing its efficiency; too small and it won't be able cool the home adequately on hot days and could break down more often.
• Residential central air conditioning is rated by a Seasonal Energy Efficiency Ratio or SEER system. Since 2006, units sold in the US must have a SEER of at least 13.
• Air conditioning systems marked with an Energy Star meet strict US government energy-efficiency guidelines.

• The most common mistake is buying a bigger system than needed; it costs more and doesn't do the job as well as one that's the right size.

• Some older homes can't accommodate ducts, or the work is extremely difficult and expensive; in those cases, consider ductless air conditioning, also called mini-split systems.

• Major manufacturers include Carrier and Trane
• The American Council for an Energy-Efficient Economy lists tips for selecting a new system and choosing a contractor.
• Sears sells central air conditioning equipment with installation service.
• HVAC contractor referrals are available through Air Conditioning Contractors of America and the Sheet Metal and Air Conditioning Contractors Association. Or search for contractors with North American Technician Excellence certification.
• Get several estimates. Ask about training and experience. Check references, search for complaints with the Better Business Bureau and make sure the contractor is properly bonded and insured, as well as licensed in your state.

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