Helpful Information When Buying A Central Air Conditioner

If summertime temperatures leave you hot under the collar, you’re not alone. More than 75 percent of U.S. homes use air conditioning, and 90 percent of new homes are equipped with central air. And eco-conscious consumers will be gratified to know that today’s air conditioners are more energy efficient, which means they cost less to run while keeping you cool, calm, and comfy.

Central Air Conditioning Types

The most common type of central air conditioning is the split system, which features a condenser outside the home, and a fan-and-coil system inside, connected by pipes carrying refrigerant. However, not every home can accommodate the ductwork needed to install central air, and a split ductless system is an option.

Central Air Conditioning

Central air-conditioning systems use ducts to distribute cooled air throughout the house. In a “split system,” the most common design, refrigerant circulates between an indoor coil and a matching outdoor condenser with compressor. The refrigerant cools the air, dehumidifying it in the process; a blower circulates air through ducts throughout the house. A variation is the “heat pump,” a type of system that functions as heater and cooler.

Split Ductless Systems

Split ductless systems have an outside condenser and one to four indoor blower units mounted high on the wall. Tubing connects these parts and circulates refrigerant. The tubing, along with an electric and drain line, is run through about a 3-inch hole hidden behind each indoor unit. Each indoor unit cools the room in which it’s installed and has its own remote control. Split ductless systems need no ductwork, making them easier to add to homes without existing ducts. They can be more expensive than window air conditioners, and professional installation is recommended.

How an Air Conditioner Works

To provide cooling throughout the home, air conditioners transfer heat from a home’s interior to the outside.

Programmable Thermostats

Proper use of a programmable thermostat can reduce your cooling costs by up to 20 percent. And using a box or ceiling fan, which cost little to run, can make you feel 3 to 4 degrees F cooler.

Upgrading an existing system

If you’re upgrading your central air, don’t assume you should buy the same-sized system. Any changes you’ve made to improve your home’s energy efficiency, such as upgrading your windows or adding insulation, can reduce your cooling needs. On the other hand, if you’ve added rooms, you might need more cooling.

Have your contractor do a load calculation based on a recognized method, such as Manual J from the ACCA. The contractor’s evaluation should include whether your ducts need to be resized, sealed and insulated, or replaced. Remember that an indoor evaporator coil and outdoor condenser must be a matched set from the same brand, or else the performance, efficiency, and capacity may not meet expectations.

New systems are 20 to 40 percent more efficient than minimum-efficiency models made even 10 years ago. Costs will vary and can depend on whether you need ductwork installed and the particular size and configuration of your home.

Installation: Find the Right Contractor

Whether you’re replacing an older air conditioner or installing one for the first time, finding a trustworthy contractor to install and service an air-conditioning system matters the most. Here’s what to do.

Ask around. Seek referrals from neighbors, family, or business associates. It’s wise to get price quotes from at least three contractors.

Check their background. Contractors who bid on your installation should show you verification of bonding and insurance, plus any required contractor’s licenses. Check with your local Better Business Bureau and consumer affairs office for complaint records. It’s a plus if technicians are certified by a trade organization, such as North American Technician Excellence or HVAC Excellence, to service residential heating and cooling equipment. Those and other similar programs assess the technician’s knowledge of specific types of equipment and their proper service methods.

Get specifics. Contractors who bid on your job should calculate required cooling capacity by using a recognized method such as the ACCA’s Residential Load Calculation Manual, also called Manual J. An additional reference for assessing ductwork needs is Manual D. The calculations produce a detailed, room-by-room analysis of cooling needs. Ask for a printout of all calculations and assumptions, including ductwork design. Be leery of a contractor who bases estimates merely on house size or vague rules of thumb.