5 Things to Know Before You Add Central Air Conditioning
Summer is here, which means for many of us, thoughts are turning to air conditioning. Let's face it—central air conditioning will change your life. No more sweaty nights tossing and turning because you haven’t installed the window units yet. For that matter, no more installing the window units—or bashing your knuckles carrying them up and down the basement stairs each spring and fall.
If you're thinking about upgrading to central air, be prepared to spend between $6,000 and $15,000, depending on the size and complexity of the job. Installation usually takes several days, and the new system will increase your property value by as much as 10%, according to Twin Cities appraiser Alan Hummel.
Here's what else you need to know.
1. Sizing it right is essential.
Air conditioning is measured by the ton, which is the cooling energy released by a one-ton block of ice melting over the course of a day. You’ll pay about $2,000 to $4,000 per ton, and a typical two-story, 2,000-square-foot house might require 3 to 3.5 tons of air conditioning—but getting the tonnage exactly right is essential. An oversized system will cool the house so quickly it doesn’t effectively dehumidify the air (a major key to comfort), and if it’s too small it will run almost constantly, increasing your energy bills and prematurely wearing out the equipment. The contractor should show you a printout of a heat-load calculation for your house, which factors in such things as your home's location, cubic feet of living space, number and size of windows, and orientation to the sun.
2. Some states incentivize efficiency.
In general, today’s systems must be 14 SEER—which stands for Seasonal Energy Efficiency Ratio and is a measure of how much cooling you get for each watt of power used—or about 40% more efficient than the 10 SEER standard that was in place until 2006. Given that your old system isn’t running at peak efficiency anymore, your cooling bills should drop by about half. Or you can opt for even higher efficiency, all the way up to 24 SEER. A 16 SEER system, for example, might add about $2,000 in upfront costs—or perhaps just $500 if your state offers an energy incentive program (you can find a list here)—and will reduce your cooling costs by another 14% a year.
3. You don't need ducts.
If you have an old central air system or forced air heat, your contractor can connect new AC equipment to the ducts that already exist inside the walls and floors of your home. Old ducts aren’t necessarily good ducts, however. If they’re leaky, you could lose 20% of your cooled (and heated) air into your attic and basement, says physicist Max Sherman, of the Lawrence Berkley National Laboratory. So have the ducts checked, and if necessary sealed. That will add another $1,000 to $3,000 to your costs.
- Read next: 5 Things to Know Before You Replace Windows
If you don’t have ducts, or the old ones are super inefficient, you have two choices: A contractor can install new ducts in the attic and or basement—and run between-floor connections through closets—for the cost of about $4,000 to $5,000. Or you can opt for ductless air conditioning: Unlike central air conditioning, which has one or two central blower units (usually in the attic) that push air through ducts, these systems have individual blower units that usually get installed on the house’s perimeter walls. You need one unit for each conditioned space, and therefore you have multiple zones throughout your house that can be more efficient than the all-or-nothing approach you get with central air conditioning. Not everyone likes the look of the blower units hanging on the walls, however, and ductless equipment will cost about 30% more for the system than for connecting new central air to existing ductwork.
4. But you do need a filter.
Do not install central air conditioning without adding a high-efficiency filter to the system. By cleaning the air as it moves through the system, it will reduce pollen and dust in the air inside your house—and it will help keep the inner workings of your AC equipment clean and efficient. A system with a “media filter” with a MERV (minimum efficiency reporting value) rating of 12 will add $500 to $1,000 to installation costs but reduce your maintenance costs by about $500 every two years, says Wes Davis, of the Air Conditioning Contractors of America, a trade organization.
5. To save the most money, wait till winter to buy.
Like shopping for a flat-screen TV the week after the Super Bowl or a 2015 model year car after the 2016s hit the lot, timing your air conditioning purchase right can save you big. “In the spring and summer, our phones are ringing off the hook,” says Robert Wilkos, of Roussos Air Conditioning in Panama City, Fla. In the winter, contractors are trying to find enough work to keep their crews busy, he says, so they typically knock 10% to 20% off their bids. Farther north, fall and spring offer similar off-season pricing and milder weather for doing the installation.