The cost of central air conditioning in 2021

Factors impacting the purchase and installation price of a central air conditioner

Key tips to remember

  • Keep our general considerations in mind
  • Match unit size and capacity with home size
  • Consider energy efficiency and alternative systems
  • Look at warranties, tax credits and rebates
  • Get estimates from trusted contractors

Hey there, homeowner, future or current! Thanks for stopping by. You’ve found the right article, and you can stop googling “cost of central air conditioner” now. We applaud you for doing your homework. The last thing a consumer should do is fail to be informed, especially when preparing for an investment as potentially complex and costly as the home heating and cooling systems category.

Of course, prices change over time, along with fluctuating materials markets and new regulations, so it’s important to have up-to-date information. Remember, knowledge is power and can save you money! In this post, we’ll take a closer look at factors influencing the wide and sometimes unpredictable central air conditioner price gap. We’ll also break down some of the reasons why this critical home appliance can get so pricey in the first place and give you all the tools you need to come up with your own air conditioning cost calculator. What is the average life of a central air conditioning system? We thought you might ask that, too. The short answer is about 15 to 20 years, but that also can depend on various factors that include maintenance and upkeep over time.

General considerations

Factors impacting HVAC system prices can range widely, from the size of your home (square footage), the unit’s SEER (Seasonal Energy Efficiency Ratio) rating, which measures its energy efficiency (more on that later), to the capacity of the system you select (measured in tons), to whatever related equipment you’re not replacing that may need to be modified. 

Additional expenses that can impact the total cost include ductwork (installation or modifications to ensure ducts meet airflow requirements on the new system for optimal performance), line set protection (preferably with a positive seal system to keep exposed wiring and refrigerant cooling tubes safe from the elements), and additional parts like evaporator coils, outdoor pads, electric disconnects, conduit, copper lines and PVC. 

Your total HVAC price could also change according to the cost of breakers and thermostats, condensate drainage configuration (which in some cases requires a pump that can add up to $400), not to mention local permits, tax credits, any applicable rebates, and the sale price of the model you end up selecting. 

Before purchasing, make sure the system you choose is the right size for the job, with appropriate ductwork, optimal airflow and adequate refrigerant. These considerations will keep your system running better and for longer.

Square footage and BTUs

If you need a new central air conditioner unit or HVAC system for your home in 2021 and are wondering about the average cost to replace yours, a good and conservative rule of thumb is to assume that the average HVAC system can cool about 400 square feet per ton of capacity, producing 12,000 BTUs per 600 square feet. 

A BTU (British Thermal Unit) is the amount of heat necessary to warm a pound of water by one degree Fahrenheit. Average BTU capacity per square foot is around 18, but 14-26 will work. To figure more precisely what you’ll need for a room, figure its square footage. Multiply length by width for square rooms, or length by width (divided by two) for a more triangular-shaped room. 

Let’s say you’re looking at the cost of central air conditioning for a 2,000 sq. ft. house. Divide that by 400 square feet of cooled area (per ton of cooling capacity), and you’ll find that a five-ton HVAC unit is what you need. You can expect to spend somewhere between $5,000 and $7,000 for a five-ton unit, including installation, labor and permit fees. A smaller house (let’s say 1,300 to 1,600 square feet) would probably need a much smaller, 2.5 ton HVAC unit. Expect to spend up to $5,000 for this job. However, total costs can range as high at $12,000 for fancier, high-capacity machines equipped for larger homes.


It’s important to get the right-size HVAC unit for the job you have in mind. This involves what’s called a load calculation by an HVAC professional. It involves factoring in the square footage of the home, while considering additional features like windows, doors, ceiling height and more. 

All of these design features can impact the effectiveness of the machine you select, and contrary to what you may assume, bigger isn’t always better. If you buy more machine than you need, your HVAC unit can cycle on and off too frequently, making it less efficient at maintaining proper temperatures or eliminating moisture. If you end up with a unit that’s too small, you’ll have similar problems. When you have an HVAC unit with the appropriate capacity for your home, it should run reliably, cool efficiently, and turn on and off less frequently.

Energy efficiency

The SEER rating we mentioned earlier determines an HVAC unit’s energy consumption (and in turn, its usage costs) over the course of a single year. Typically, SEER numbers range between 13 and 26; most units average between 15 and 18. 

A higher SEER rating means the unit’s performance is more efficient and uses less energy. It also means you’re getting a machine that costs less to operate over the life of the unit. However, you will likely pay significantly more for it up front, an important trade-off to consider. 

An HVAC unit in the standard efficiency range of around SEER 14 will cost you around $3,000-$5,000, which could be less than half the purchase and installation price of a SEER 24-rated system, due to the large efficiency gap. Exact numbers are difficult to predict and require professional quotes.


All of the best-rated HVAC brands have a wide selection of models designed to meet your needs and fit your home. While some of the better-known brands will cost more (and there are perfectly decent models available at a lower price point), in general it’s still true that you do get what you pay for Paying a little more now and a little less on maintenance and repairs over time can make for a worthy investment in your home, especially if you plan on living in your house for a while.

Electrical modifications

Electrical modifications are sometimes required during an HVAC unit installation. Whether you need an update to the control wiring to accommodate a more advanced thermostat or an update to breakers in your control panel, modifications are a potential additional expense to consider and plan for. It’s always best to stick with a licensed electrician when any of these potential issues arise.


Every new system sold comes with some sort of warranty. Standard coverage ranges between 5 and 15 years, with 10 years on average. This standard manufacturer’s warranty should include equipment and parts, though many brands will also offer extended warranty coverage, which may cover additional parts and years of maintenance. 

These warranties can end up saving you money on a long-lived system, as a typical repair visit might cost you $350 out of pocket without coverage. However, extended warranties can be expensive and have restrictions on the number of repair and maintenance visits allowed. Your contractor will also likely offer a warranty on the labor for installation, wiring and repairs. When considering warranties, consider how long you plan to stay in your home. Not all are transferrable to subsequent owners.

Alternative systems

Sometimes called central air conditioning and heating systems, an HVAC unit that uses ductwork to both heat and cool an entire home is the most common system in use today. However, these systems are not your only option. Depending on your needs, there are alternatives. 

A split AC system, sometimes known as a mini-split system, usually refers to a ductless system. A ductless AC system is a great option for smaller homes, historical properties or any house where the space needed for adding ductwork just doesn’t seem practical or desired. Ductless systems can be as simple and affordable as a window-placed air conditioner ($150-$500) or a portable unit that can be moved around the home (similar price range to window units), or as comprehensive as a whole-house system. 

These whole-house ductless systems can cost as much or more than a traditional system installed with ducts, ranging widely ($2,000-$14,000) according to the size of your home and the system you choose. Some people choose to go with a split system that includes a heat pump. These solutions can be less expensive but can also require more maintenance and work best in warmer climates.

Tax credits and rebates

Local utility organizations and HVAC manufacturers both offer rebates on efficient systems from time to time, so keep an eye out for cash-back offers before you make a purchase. Even the U.S. government offers a federal tax break when you purchase an energy-efficient HVAC system that meets CEE (Consortium for Energy Efficiency) standards before December 31, 2021. The IRS grants a $300 tax credit for split-system ACs with a SEER rating of 16 or greater, or packaged ACs with SEER ratings of 14 and higher. Looking into each opportunity could produce significant savings

Estimates and contractors

Your cost of installation includes labor, materials, wiring, and sometimes ductwork and the related mounting hardware, as well as removal and disposal of your existing HVAC system, if you have one. Your total cost of installation is worth negotiating, and while some contractors won’t budge, others might, especially if you arm yourself with multiple estimates.lan on getting at least three estimates from experienced and insured contractors. 

Make sure you begin by finding potential installers that are certified by the manufacturer to install the brand of HVAC unit you plan to purchase. This extra step can go a long way toward ensuring your machine’s performance and durability over the long haul. First, you’ll need a licensed, insured contractor from each company you’ve requested an estimate from to assess your needs. Once you’ve arrived at a deal, after reviewing estimates from several contractors, make sure you ask whether the contractor has included labor and any other fees in the estimate. Your contractor will typically arrive with team members who will help with the install.

If you like fixing things yourself, check out our post on DIY air conditioning repair or our findings on how long your air conditioner should last. For more on the subject, read our post on three ways to take care of your air conditioner, and if you’re wondering whether home warranties cover AC systems, we have answers for you.

The information in this article is intended to provide guidance on the proper maintenance and care of systems and appliances in the home. Not all of the topics mentioned are covered by our home warranty or maintenance plans. Please review your home warranty contract carefully to understand your coverage.


Related stories