Ashburn, VA

How much does it cost to install a central air conditioner?

$2,500 – $7,500 AC unit replacement cost (3 to 5 ton)
$6,000 – $12,000 AC unit + ductwork installation cost

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December 27, 2021

Reviewed by Tom Grupa and 6 expert AC installers on HomeGuide.

Cost to install central air

The average cost to install central air is $2,500 to $7,500, depending on the size (tons), brand, and efficiency rating (SEER). New central AC unit prices are $1,000 to $5,000, plus $1,000 to $2,500 for labor to install.

Average cost to install central air conditioning - chart
Average cost to install central air conditioning - chart

Cost to install central air
Home size (square feet) AC unit tons Total cost installed
1,000 1.5 – 2 $2,000 – $5,500
1,200 2 – 2.5 $2,500 – $6,000
1,500 2.5 – 3 $2,700 – $6,500
1,600 3 – 3.5 $3,000 – $7,000
1,800 3 – 4 $3,000 – $7,500
2,000 3.5 – 4.5 $3,100 – $7,800
2,200 4 – 5 $3,500 – $8,000
2,500 4.5 – 5 $3,700 – $8,000
3,000 5+ $4,000 – $8,500

Central air installation cost calculator

The following table shows the average cost to install or replace a central AC unit.

Central air installation cost calculator
National average cost $4,700
Minimum cost $1,100
Maximum cost $15,000
Average cost range $2,500 to $7,500

Cost data is from research and project costs reported by HomeGuide members.

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New AC unit cost by size

AC units are sized in tons. One ton of cooling capacity equals 12,000 British Thermal Units (BTU). One ton of air conditioning cools 450 to 600 square feet on average, depending on the home's layout, insulation, and local climate.

AC unit cost by tons

Replacing a 3 to 5-ton AC unit costs $3,000 to $8,000 for a 1,500 to 2,500 square foot home.

AC unit cost by tons
Tonnage BTUs AC unit prices AC cost installed
1.5 tons 18,000 BTU $1,000 – $3,800 $2,000 – $5,000
2 tons 24,000 BTU $1,200 – $4,000 $2,500 – $5,500
2.5 tons 30,000 BTU $1,500 – $4,500 $2,700 – $6,000
3 tons 36,000 BTU $1,700 – $5,000 $3,000 – $6,500
3.5 tons 42,000 BTU $1,800 – $5,200 $3,100 – $7,000
4 tons 48,000 BTU $2,000 – $5,500 $3,500 – $7,500
5 tons 60,000 BTU $2,500 – $6,000 $4,000 – $8,000

New Black AC Unit Installed For Central Air Conditioning

Whole-house AC cost per square foot

Installing central air for a 1,200 square foot house costs $2,500 to $6,000. Installing central air for a 2,000 square foot home costs $3,100 to $7,800 or more. Homes over 3,000 square feet may require two condenser units.

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Central air conditioner prices

Central air conditioner prices are $1,000 to $8,500 for the unit alone, depending on the size, brand, and efficiency. Large systems with high SEER ratings or AC units from top brands cost the most.

Air conditioner prices by SEER rating

Air conditioners have a Seasonal Energy Efficiency Ratio (SEER) rating of 13 to 26. AC units with a higher SEER rating cost more upfront but are more efficient and reduce long-term energy costs.

Air conditioner prices by SEER rating
SEER Efficiency AC unit prices Total cost installed
13 – 14 SEER Standard efficiency $1,000 – $4,200 $2,500 – $6,000
15 – 16 SEER High efficiency $1,500 – $5,700 $3,000 – $7,500
17 – 18 SEER High efficiency $1,800 – $6,100 $3,500 – $8,600
19 – 21 SEER Very high efficiency $2,500 – $7,500 $4,000 – $10,000
22 – 26 SEER Maximum efficiency $3,700 – $8,500 $6,000 – $11,000
  • The Department of Energy mandates a minimum SEER of 13 in the northern U.S. and 14 in the southern U.S.
  • In 2023, the minimum SEER standard increases to 14 in the northern U.S. and 14.5 to 15 in the southern U.S., depending on the AC system's size.

Central AC unit prices by brand

Central AC unit prices by brand
Brand SEER AC unit prices Total cost installed
Aire-Flo 13 – 14 $1,000 – $2,000 $2,400 – $4,500
Amana 13 – 24 $1,300 – $4,500 $3,000 – $7,500
American Standard 13 – 20 $1,500 – $4,300 $3,800 – $8,000
Armstrong 13 – 20 $1,100 – $2,500 $3,000 – $4,600
Bryant 13 – 20 $1,400 – $3,500 $2,500 – $6,800
Carrier 13 – 24 $2,500 – $5,800 $4,700 – $8,700
Coleman 13 – 20 $1,300 – $3,500 $2,500 – $5,000
Comfortmaker 13 – 19 $1,300 – $3,000 $2,800 – $5,800
Frigidaire 13 – 20 $1,300 – $3,000 $2,500 – $4,800
Goodman 14 – 24 $1,200 – $3,000 $3,200 – $5,000
Heil 13 – 19 $1,400 – $3,000 $2,800 – $4,800
Lennox 13 – 26 $1,600 – $5,600 $5,300 – $9,000
Payne 13 – 17 $1,000 – $1,800 $2,500 – $3,900
Rheem / Ruud 13 – 20 $1,800 – $5,500 $3,600 – $8,500
Tempstar 13 – 19 $1,300 – $3,000 $2,600 – $5,200
Trane 14 – 22 $1,600 – $5,800 $4,000 – $9,000
York 13 – 21 $1,400 – $4,700 $3,500 – $8,000

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Air conditioner replacement cost by type

Air conditioner replacement cost by type
AC type AC unit price Total cost installed
Central air conditioner $1,000 – $5,000 $2,500 – $7,500
Central air conditioner and ductwork $3,400 – $9,000 $6,000 – $12,000
Ductless mini-split AC system $1,500 – $8,000 $3,000 – $10,000
Window AC unit $150 – $800 $300 – $1,100
Portable AC unit* $200 – $900 $200 – $900
HVAC system (furnace and AC) $2,400 – $5,600 $4,800 – $9,400
Air-source heat pump $2,000 – $4,000 $4,000 – $8,000
Geothermal heat pump $2,500 – $8,000 $15,000 – $35,000

*No installation required.

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Central air system types and speeds

Central air conditioning systems come in two types:

  • A split-system AC features an outdoor condenser unit containing the compressor and an indoor air handler cabinet containing the evaporator coil. Most homes in the U.S. have split systems.
  • A packaged air conditioner combines the condenser, compressor, and evaporator coil in a single outdoor cabinet, typically used in commercial settings.

Central AC units come with different compressors:

  • Single-stage air conditioners are the cheapest but have only one speed and run at full capacity until the indoor air reaches the set temperature.
  • Two-stage air conditioners have two speeds—full capacity and 60% to 70% capacity. Two-stage units run more quietly and efficiently but cost more than single-stage units.
  • Variable-speed air conditioners cost the most to install but operate at any capacity, making them more efficient, better at dehumidifying, and the least expensive to run.

Ductless mini-split air conditioning cost

Ductless mini-split AC installation costs $3,000 to $10,000 on average, depending on the number of zones, BTU size, SEER rating, and brand. A ductless AC system features an outdoor condenser that supports up to five indoor air handlers, also called "zones".

Window or portable AC unit

A window AC unit costs $300 to $1,100 with installation or $150 to $800 for the unit alone. Window air conditioner prices depend on the size, brand, efficiency, and features.

A portable AC unit costs $200 to $900 and does not require installation. A portable unit uses a hose to vent hot air outside through a window, wall, ceiling, or door.

HVAC replacement – central heat and air unit

The cost for HVAC replacement depends on whether the home has a furnace or heat pump:

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Home AC unit and system installation cost factors

The labor cost to install central air conditioning is $1,000 to $2,500 or more, depending on if it includes new ductwork. Labor makes up 40% to 60% of the total installation cost.

New AC unit cost to install - chart
New AC unit cost to install - chart

Home AC unit and system cost to install
Factor Average cost
New AC unit $1,000 – $5,000
Labor cost to install AC $1,500 – $2,500
Ductwork installation* $1,400 – $6,600
Total cost to install $2,500 – $14,100

*May not be required.

The following factors affect the cost to install a central AC unit:

  • AC system size – AC units in larger ton sizes cost more.
  • Efficiency and SEER rating – High-efficiency models with higher SEER ratings cost more than standard efficiency units.
  • System type – Split systems typically cost less than packaged systems.
  • Location – Installing a condenser unit on the ground costs less than installing it on a rooftop.
  • Accessibility – Installation costs more for AC systems in difficult-to-access areas like attics and crawlspaces.
  • Zoning – Adding an HVAC zoning system costs $1,700 to $4,500. Large homes may benefit from a zoned AC system to minimize the required AC unit size and reduce energy costs.
  • A condenser pad costs $40 to $250, depending on if the pad is prefab composite or poured concrete.
  • Permits for AC replacement cost $100 to $250. Permits for new AC installations with ductwork cost $250 to $1,500. Contractors typically include permit fees in the estimate.
  • Removing an old air conditioner costs $50 to $200, depending on local disposal and freon removal fees.
  • Federal tax credits expired in 2021, but new AC units may qualify for local tax credits and rebates. Check the Energy Star rebate finder and the Database of State Incentives for Renewables & Efficiency (DSIRE) for available rebates and tax incentives.
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Cost to add central air conditioning to an existing furnace

Adding air conditioning to an existing furnace costs $3,000 to $5,000, depending on the home size and the new AC unit's SEER rating. Adding central AC to a forced-air system may require other upgrades:

  • Sealing the ductwork to prevent leaks and improve efficiency
  • Upgrading the furnace blower to move enough cool air through the home
  • Replacing old supply registers with wider vent grilles to improve airflow

Install ductwork for central air

The average cost to install ductwork for central air is $2,400 to $6,600 to retrofit a home without existing ducts. Replacing HVAC ductwork costs $1,400 to $5,600, depending on the home's size.

Cost to install ductwork for central air
Install type Cost per linear foot Average cost
New duct installation / retrofit $40 – $65 $2,400 – $6,600
Ductwork replacement $25 – $55 $1,400 – $5,600
  • Ductwork repair costs $200 to $700 for minor jobs, depending on the duct size, accessibility, and service type.
  • Air duct cleaning costs $300 to $700 on average or $25 to $45 per vent.

Additional costs to put in central air

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Frequently asked questions

What size air conditioner do I need?

An air conditioner needs 16 to 30 BTUs per square foot of living space on average. Hire a licensed HVAC contractor to perform a Manual J Load calculation and determine the home's ideal AC size.

A Manual J Load calculation considers factors like:

  • Zone, climate, and humidity
  • Square footage and number of stories
  • Home layout and ceiling height
  • Number, type, and placement of windows
  • Sun exposure or shade
  • Insulation amount and quality
  • Number of people in the home
  • Heat-generating appliances
  • Basement, slab, or crawlspace conditions

What Size AC Do I Need? - AC Unit Size Map - BTUs Per Square Foot

The following table shows the recommended AC size in tons based on the home's square footage and climate zone:

AC unit size calculator
AC size Zone 1 Zone 2 Zone 3 Zone 4 Zone 5
1.5 Tons 600 – 900 sf 600 – 950 sf 600 – 1000 sf 700 – 1050 sf 700 – 1100 sf
2 Tons 900 – 1200 sf 950 – 1250 sf 1000 – 1300 sf 1050 – 1350 sf 1100 – 1400 sf
2.5 Tons 1200 – 1500 sf 1250 – 1550 sf 1300 – 1600 sf 1350 – 1600 sf 1400 – 1650 sf
3 Tons 1500 – 1800 sf 1500 – 1850 sf 1600 – 1900 sf 1600 – 2000 sf 1650 – 2100 sf
3.5 Tons 1800 – 2100 sf 1850 – 2150 sf 1900 – 2200 sf 2000 – 2250 sf 2100 – 2300 sf
4 Tons 2100 – 2400 sf 2150 – 2500 sf 2200 – 2600 sf 2250 – 2700 sf 2300 – 2700 sf
5 Tons 2400 – 3000 sf 2500 – 3100 sf 2600 – 3200 sf 2750 – 3300 sf 2700 – 3300 sf

Do not buy a cooling system that is too small or too large for the home:

  • An oversized AC will “short-cycle”, turning off and on more often. Short cycling uses more energy, reduces the system’s lifespan, and prevents the AC from dehumidifying the home.
  • An AC unit that is too small will constantly run, reducing efficiency and adding wear and tear.

Does central air increase home value? Is central air worth it?

Installing central air conditioning increases a home's resale value by 2% to 10%, depending on the location. Central air is a good investment in warm climates but provides less value in regions with mild summer weather. Replacing an existing central air system maintains but does not increase the home's value.

Installing a new high-efficiency AC unit with a high SEER rating provides a return on investment (ROI) of 70% to 85%.

How much does central air conditioning cost to run?

The cost to run central air conditioning is $80 to $200 per month on average, depending on the AC unit's BTU size, SEER rating, and local utility rates.

Air conditioning cost to run
AC type Monthly cost to run
Central air conditioning $80 – $200
Ductless mini-split AC $30 – $150
Window AC unit $12 – $120

*Running 8 hours per day.

  • New AC units are 20% to 40% more energy-efficient than models more than 10 years old.
  • Look for ENERGY STAR-certified units, which have the highest efficiency rating.
  • Use a programmable thermostat to reduce energy costs.

How long do AC units last?

An air conditioner lasts 12 to 15 years if correctly sized for the home and properly maintained. An AC unit's lifespan depends on the quality, environment, and usage. Improperly sized air conditioners or units located in areas with extreme heat typically have a shorter lifespan.

Signs an air conditioner needs to be replaced:

  • Warm air or limited airflow from the vents
  • Excessive humidity in the home
  • Moldy, musty, or smoky odors
  • Loud or unusual noises from the AC system
  • Increased utility and energy bills
  • AC is more than 10 years old
  • AC uses R-22 Freon
  • AC requires frequent repairs
  • The repair cost is at least 50% of the cost of a new AC.
  • The repair cost multiplied by the system's age in years exceeds $5,000.

How long is an average air conditioner warranty?

An air conditioner warranty lasts 10 to 15 years if the product is registered within 60 days of installation. Coverage timeframes for individual parts vary from 5 to 20 years, depending on the brand. Standard AC warranties cover equipment malfunctions but typically do not cover labor.

An AC tune-up costs $70 to $200. Failing to perform regular AC maintenance may void the manufacturer's warranty.

How long does it take to install a central AC unit?

Installing a central AC unit takes 1 to 2 days on average if using the existing ductwork. AC installations requiring new ductwork take 3 to 5 days or more, depending on the home's size, age, duct type, and crew size.

What is the difference between a heat pump and an air conditioner?

An air conditioner can cool but cannot heat. A heat pump can cool in the same way but can also reverse itself to provide heat instead when needed. Air conditioners are typically paired with a furnace to heat the home during cold months.

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Getting AC unit replacement quotes and estimates

Before hiring an AC company near you, be sure to:

  • Get at least three estimates to compare.
  • Look for a NATE-certified company with experience installing central AC units.
  • Select an HVAC contractor who will perform a complete home evaluation to assess your cooling needs.
  • Read reviews and check out their previous work on HomeGuide and Google.
  • Select companies that are insured, bonded, and have been in business longer than five years.
  • When comparing quotes, confirm they include equipment of the same size and quality.
  • Avoid selecting the lowest quote as quality may suffer.
  • Get a detailed estimate, contract, and warranty in writing before the work begins.
  • Never pay in full before the project starts. Follow a payment plan instead for work completed.

Questions to ask AC installers

  • Are you licensed and insured to install an HVAC system?
  • How long have you been in business?
  • Is a central air or ductless mini-split system best for my needs?
  • What AC unit size or capacity do you recommend for my house?
  • What is the SEER rating of the AC unit you recommend for my house?
  • Can the existing ductwork be used with the new unit?
  • Will you inspect my existing ductwork for leaks, mold, and asbestos?
  • How much will it cost to remove my old AC unit?
  • What extra costs should I expect?
  • What upgrades are available for new AC units?
  • How much will I save on energy costs each month?
  • Which brands do you recommend and why?
  • Are there any local or federal rebates or tax credits available?
  • How long is the warranty, and what does it cover?
  • How long will it take to install the central air system?
  • What kind of maintenance will the system require?
  • Can I do any maintenance myself?
  • How long will the system last?

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