Install Air Conditioning - Costs, Tasks, and Estimates

Install Air Conditioning | A guide to air conditioning installation, including reasons for varying costs, guides to finding contractors, and more

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This guide explains the process of installing central air conditioning. If you need a contractor to install air conditioning, simply fill out the form on the right or follow this link. As soon as you do, you'll receive free central air conditioner prices from up to four top-rated central air conditioning contractors in your area. Our network of contractors is very selective -- we verify insurance and state licenses to ensure when they install air conditioning they do it right.

Central air conditioning has earned a deserved reputation as one of the most reliable cooling systems on the market, but unfortunately the payoff of evenly distributed, low-cost cooling comes with a high initial price tag and the need to hire a professional to install air conditioning.

The task to install central is one best left to contractors because a slight miscalculation in the installation can lead to a system that’s less efficient than models developed three decades ago, which are usually about 30 to 50 percent less efficient than modern systems.

Beyond finding a contractor with a low estimate and choosing the right system for their house, homeowners’ role in the task to install air conditioning is limited to choosing the location for your central AC, an important aesthetic choice that can lead to savings down the road. A contractor will usually recommend a place to install the unit.

Generally, it’s recommended that you choose to install air conditioning in a shaded area outside the home. An air conditioning unit protected by shade can cost about 2 percent less to operate than one open to the sun’s rays.

Although you won’t be performing the work, it can help to know what tasks lay ahead for central ac installation when seeking estimates and assessing a contractors’ progress.


Central air conditioners are made up of two primary components: a condenser and evaporator. The condenser is housed inside an outdoor box on a concrete slab. The evaporator is set above the furnace at the primary junction of the interior ductwork.

Central air conditioning operates through the motor, blower, and ductwork working in harmony to create forced-air distribution to ensure even cooling throughout the home. If one of these elements isn’t working correctly, you can’t cool your home properly, an uncomfortable inconvenience that also wastes energy.

The motor and blower may require maintenance down the road, but will be in top working condition new air conditioning systems. That’s why ductwork is the key aspect when a contractor installs central AC. Nearly all central air conditioning units require ducts to operate. Ducts, simply put, are the thin aluminum distribution tubes tucked behind the walls of your home that lead to vents scattered throughout the house. Generally, if your home has never had a central air system, whether heating or cooling, a contractor will need to install new ductwork, which can add about $3,000 to your bill, depending on the size, design, and lay-out of the home.

For most homeowners with ductwork in place, the contractor’s task to install air conditioning won’t go further than setting up the big box next to their house.


If you’re replacing an old central air conditioning system or already have a central heating system in place, you likely will not need new ductwork when you install air conditioning. However, it may be beneficial to upgrade the interior ductwork in rare cases. As heating and cooling specialists have learned more about how air distribution works, duct sizing and configuration has changed. If your home is a few decades old or more, the original ductwork should work fine. Ducts in these homes were usually large, which is generally better for central air conditioning. However, if the house was built in the last few decades, ducts may be overly small and won’t distribute cool air efficiently. It is sometimes more cost effective to not replace old ductwork, because the cost can run in the thousands and the payout from reduced energy costs may not make up the difference.

Ducts are set in a spiderweb system throughout the house with the lead duct generally going from the outdoor unit directly upward into the attic. From there it extends outward toward the exterior walls and downward throughout the home. The smaller the spiderweb, the better, because some cool air is lost from its route from the air conditioning unit to the vents. Contractors will often assess the best set-up using industry standard guides such as the Air Conditioning Contractors of America Manual D, a dense manual for proper ductwork.

Some homes lack space for ductwork, meaning contractors will need to make room. Rarely, this may require some minor deconstruction of a home and additions to the walls to hide the ductwork. Ducts going to the top floor of a home--the first floor in one-story houses--will usually be set downward in-between the joists, otherwise known as support beams, in the walls. In homes with more than one story, ducts that reach the first floor are usually run through closets and end at ceiling vents. This may mean less closet space, but a contractor will cover the ductwork to ensure the closet remains aesthetically pleasing.

For the most part, the installation of ductwork will have little to no impact to a home. All of it fits neatly hidden behind the walls, ceilings, and floors.


Should you wish to avoid paying for costs that come when you install air conditioning, there are alternatives to central air conditioning. Window units can cool a room, are cheap to buy, but are more expensive to operate. Wall-mounted units are a better looking, more costly version of window units that are more expensive to operate than central air conditioning. Some split-air conditioning systems can cool four zones in a home and rely on a three-inch conduit to transfer cool air, which removes the need for ductwork. However, these units are expensive: about $1,500 to $2,000 for a unit capable of cooling a 600-square-foot space.


Install Air Conditioning