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Can I Use Existing Ductwork for my Central Air Installation?

Last Updated: January 19, 2022

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As the weather gets warmer and the sweating starts, many people begin looking for relief from the heat and a way to cool down their home. Installing a central air system is a great way to beat the heat and ride out the summer. But there are those who worry about the complexity and expense of the task, as well as whether their home can support a central air system. The truth is, central air is suitable for the majority of homes (even those without existing ductwork). And, though not exactly cheap, central air installation costs about the same as most other remodeling projects. In addition, when it comes time to sell your home, you can expect to recoup most of these costs.

Utilizing Your Current Ducts #

It is definitely possible to use your existing duct system for a central air installation. But first, they need to be inspected. Air conditioning produces a greater volume of air, so modifications to your ductwork may be required to support this.

You may need to replace older supply registers, since many register grilles are too narrow for the air to flow properly. Furnace blowers often need to be upsized, as undersized blowers do not move enough air through the coils, which can cause them to freeze. It is also important that the ducts be properly sealed to ensure the maximum efficiency of your air conditioner. Though it adds to the cost, it is recommended that any inspections and modifications be performed by a professional; even the smallest mistake can cause major issues and costly repairs down the line.

Replacing Your Ductwork #

If your existing ductwork can't be modified, new ducts and vents must be installed to ensure the air conditioner has a proper flow system. This is best left to a professional, as the process is highly labor intensive and requires cutting into the ceilings, floors, and walls of your home.

Most retrofitted AC systems have the fan-and-coil unit mounted in the attic, so supply and return ducts must be run to ceiling registers in the first and second floor. Generally, ducts that feed into second floor rooms run across the floor of the attic and down between the attic floor joists into ceiling registers. For first floor rooms, ducts run through closets on the second floor whenever possible.

You may fear that running ducts through a closet will take up most of the available space. Actually, ductwork takes up very little space. Some contractors propose using flex duct to save space, as it is a smaller and more flexible option than traditional rigid square ducts. However, if it's a closet you use, avoid the flex duct option. It is easily punctured and has lower durability.

How Much Does Central Air Installation Cost? #

The price to install a central air system varies from home to home. Factors such as whether the existing ductwork is usable, modifications are needed, and the size of the home all impact the final cost.

  • The average cost of installing central air in a 1,600 to 2,000 square foot house with existing ductwork is between $3,900 and $5,000.
  • Homes with a gas, forced-air furnace typically only require the installation of a coil and electric setup, which costs between $2,000 and $3,000.
  • If the ductwork requires any modifications, this adds to the price. Though costs vary based on the scope of the work needed, you can expect to pay between $1,000 and $3,000 extra.
  • If there is no existing ductwork or it needs to be replaced entirely, the cost of installing the new ducts and central air system averages between $8,000 and $15,000.

How to Save Money on Your Central Air Installation #

Again, installing air conditioning in your home is a relatively expensive project, but there are some ways to save money overall.

First, have a professional handle the initial assessment to ensure the air conditioning unit you choose is the right size. In addition to calculating heat load, they'll look at factors such as the size of your home, insulation, and the number of windows you have. This keeps you from getting a unit that is too big and costs more to operate, but also from getting a unit that is too small and doesn't cool your home properly (and burns out early).

Don't be afraid to shop around either. Many people choose the first contractor they talk to, but looking at other options is a good idea. Costs and level of service vary from contractor to contractor and you can make a more informed decision when you've reviewed proposals from multiple vendors. It is also a good idea to schedule your installation during the cooler months. In the summer, contractors are often overloaded with work and prices tend to increase. But when it's cooler, their schedules are more open and prices are usually lower.

Use Our Free Service and Find Central Air Conditioning Companies Near You #

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