In many parts of the country, air conditioning can make or break a deal. Bulky, energy-sucking window units are an instant turnoff, while a silent and efficient central air system can be the single feature that convinces a wavering prospect to submit an offer.

For these reasons, it's important that you know how to properly promote your listings' air conditioning assets and counter objections when a home doesn't have a smooth-running system — or any system at all. Likewise, if you're working with buyers, it's smart to know the benefits and drawbacks of various air-conditioning options.

A Little History

Let's start with the basics. Air conditioning uses the same technology as a refrigerator. Coolant runs in a loop, absorbing heat from indoor air and releasing it outside. As essential as it is for today's home buyers, the technology hasn't been around for that long.

Air conditioning as we know it today was first seen in the early 20^th century. The earliest of cooling systems were used in textile and paper factories, and in the 1930s air conditioning was added to railroad cars. By the 1950s, units for cooling individual rooms were becoming more common in businesses and in homes.

Today, these are the most frequently used air conditioning options:

• Window units. These do the trick when there's no other system in place. The biggest drawback: They are quite ugly, hog window space, and block the view. They work best with double hung windows, which have two sashes that move vertically. With casement windows, which are hinged on the side like a door, window units are problematic to install.

• Through-wall units. Similar to window units, but they go through an exterior wall, usually beneath a window. These units must be fit into a sleeve for support. They preserve the view out the window, but require a sizeable hole in the exterior wall. One unit cools just one room.

• Central air conditioning systems. A system of ducts delivers air to rooms from a central source, cooling the entire house. A central system typically has a compressor outside the house; this is where heat is released. Although the compressor is unsightly, it can be concealed with planting or fencing.

• Ductless air conditioning systems. An outdoor compressor connects to one or more cooling units installed onto the interior of an exterior wall of a building. This eliminates the need for a duct system in the building. The opening in the exterior wall is just a matter of inches and tubing connects the indoor and outdoor components. The units operate independently so one room or multiple rooms can be cooled at once.

Central Air Wins With Buyers

While there are lots of options, central air conditioning is most people's first choice. It's the least visible option and cools the entire house. Central air is the norm in new construction — especially in warmer climates — and is less common in older properties and cooler climates.

If you're dealing with a home that doesn't have central air, it's good to find out about the possibility of adding it. The ease of adding a system depends on the existing heating system. If there is a forced-air heating system in place, the necessary ducts and blower are already there, and that's a good thing.

A forced air system has a furnace, which heats air, and a blower and ducts to distribute the warmed air. With this heating system, the installation of a central air conditioning is easiest and typically entails adding an indoor cooling coil near the furnace, an outdoor compressor, and thermostats.

If your listing has central air, be sure to promote it among the home's other features in advertisements and at open houses. Newer energy-efficient systems, particularly those qualified by the U.S. government's EnergyStar program, are attractive to buyers and should be called out in all of your marketing materials. Not only do they reduce pollution, they also cut down on energy bills.

A More Cumbersome Option

It's more troublesome to add central air if the home has a hot water, steam, or radiant heating system. In such cases, the central air conditioning system cannot piggyback onto the heating system.

Hot water heating systems typically have a boiler that heats water and pipes that distribute the water or steam throughout the house. To add central air, ducts would have to be installed — an arduous task. The ducts can be run through the attic and basement in a house and cut into the finished rooms from above or below. It might be necessary to lower the ceiling in areas, which can change the overall proportions of the architecture.

There are air conditioning systems that have mini-ducts instead of the usual bulkier ducts. These can be a good alternative that won't require you to lower ceilings or alter the architectural integrity.

Know the Costs

Since there are many variables, the best way to get an estimate on the cost of installing central air conditioning is to have an air conditioning contractor look at the space. In an old house, it's also a wise idea to check whether the existing power supply can handle a new central air system. If it can't, the electrical system will have to be upgraded, too — tacking on an additional cost.

However, it's better to have the cost estimate in hand to show potential buyers than it is avoid the issue altogether. After all, some buyers may prefer to install a new system in an older property than to live with a less-than-efficient system that's already in place.

Clients who fall in love with an older property that doesn't have central air also should get an estimate before they submit an offer. If air conditioning is a must, they may realize that the project would be too costly or disruptive to the house

Do You Have an Architectural Question?
If you have a question about a home style, please send a digital photograph and your question to REALTOR® Magazine Online. E-mail Kelly Quigley at kquigley@realtors.org.