The average national cost to install central air conditioning is $5,211 with most homeowners spending between $3,686 and $7,174. This data is based on actual project costs as reported by HomeAdvisor members.
When the hot summer months approach and you find yourself standing in front of the fan to keep cool, you dream of having air conditioning to cool down your whole house. While air conditioning installation isn't always complicated, it's usually best to work with an air conditioning contractor who will help to ensure it's done correctly. Here is more information on air conditioner installation and finding the right model for your home:
The size of your home will determine the type of air conditioning system you will need.
There are several types of systems, including:
Window units: installed in windows as a singular unit
Split systems: either as mini-split (ductless) or central systems that are installed as inside and outside units
Central system: uses duct system that's usually combined with the heating system to cool a whole house
Portable units: comes as a split, hose or evaporative system for ease of movement around the house
A window air conditioning unit will generally suffice to keep a smaller home cool on warm spring and summer days. The cost to install a window air conditioner averages between $150 and $300, depending on the size you need. Installing a window air conditioning unit can bring added comfort for a reasonable price, but it will be less powerful than a central air conditioning system.
If you have a bigger home with multiple rooms, you will probably need to have a central air conditioning system installed. Homeowners can pay between $500 and $4,000 for central air conditioning. The final cost will depend on the unit, additional installation items such as ductwork and the professional's installation rates. Here are some additional factors that will determine the kind of system you will need, as well as its price.
Measuring Home Size in BTUs
The first major factor in determining what kind of air conditioning system you'll need is the size of your home. Air conditioning units are measured in tons or the amount of heat they can remove from a home in one hour in British thermal units (BTUs)--more information on this measurement below. The larger your house, the more cooling power you'll need. However, bigger isn't better in every scenario. If the system is too large it will cycle on and off all the time, wasting energy and emitting a loud, disruptive sound. On the other hand, if the system is too small, it will run constantly and cool your house inefficiently.
New Air Conditioning Unit Load Calculation
An air conditioning contractor will do a load calculation to determine the proper air conditioning unit for your home. This calculation takes into account the climate, size, shape and orientation of your home, as well as its square footage. A professional will also look at the insulation, windows, walls, floors and other materials that compose your home. He will then examine any leaks, seals and existing ducts or vents. The general rule is that every 500 or 600 square feet requires one ton of cooling. However, this calculation varies from place to place and contractor to contractor.
Load calculating is often referred to as the Manual J methodology. Cooling professionals use a variety of computations to analyze your home's heating and cooling characteristics, determining how much air it will lose. Factoring in environmental considerations like geography and solar rays, professionals can decide which system will best cool your home. There are two types of Manual J load calculations:
Whole House: Provides the air conditioning load calculations for a whole house with an existing duct system.
Room by Room: Used for calculating the air conditioning loads in every room of a house, which contributes to determining individual duct sizes and layout of a duct system
What are EER and SEER Ratings?
The best cooling unit for your home will be the most energy efficient and the least expensive to run. Air conditioning professionals help determine this factor in their load calculations, but the next step is looking at the energy efficiency ratio (EER) and seasonal energy efficiency ratio (SEER) ratings of cooling units. Here's what you need to know about these two units of efficiency.
An EER certifies the cooling efficiency of HVAC units. It's calculated by the rate of the cooling in British thermal units (BTUs) per hour and divided by the rate of energy input in watts at a specific temperature. The calculation goes as BTUH/WATT at dry bulb (db) versus wet bulb (wb) temperatures. The optimal rating for a cooling unit is about 80db/67wb inside and 95db/75wb outside.
An air conditioning system's SEER is especially important if you live in a climate that changes temperature dramatically. The SEER is determined by the cooling output during the winter divided by its electric input during the winter. The higher the SEER rating, the more efficient it will be. Cooling units specifically must have a minimum SEER of 13 as of January 2006, according to U.S. standards, so if you live in a home with a system installed before then, consider having it replaced. SEER 13 units increase home efficiency by 30 percent.
Once you've determined the size of the air conditioning unit you need, it's time to look at different brands. Various manufacturers produce heating and cooling units, and there are pros and cons to each. Units also vary in cost, depending on bells and whistles. So, consult with a professional about what you need and ask about any additional features that may benefit your home. Here are some of the cooling unit manufacturers and their average costs (in alphabetical order):
There are a few factors in addition to load calculation, energy efficiency ratings and brand manufacturers that homeowners should consider before they invest in an air conditioning system:
Installing the Air Conditioning Unit
It's important to have made an informed decision about an air conditioning system before initiating an installation, as this will determine a large percentage of your cost. If you decide to have a split or central system installed, you will need to hire an air conditioning professional to install the system. You cannot do this installation as a DIY project because it involves handling refrigerant, which cools the air. Professionals must be licensed by the Environmental Protection Agency (EPA) before they can handle this substance because it's a harmful chemical.
Installing an air conditioning system is an involved process. To that end, it requires the help of many professionals whose rates will drive up the cost. You will need at least:
Air conditioning contractor: he or she performs an assessment to determine what kind of system you need and installs it
Assistant(s): additional team that helps with the wiring, ductwork and metal bracket mounting
You will also be charged for the materials involved in the installation, including the air conditioning unit and chemicals. Check with your contractor to see whether you might cut costs by buying the air conditioning system yourself or using existing heating system ductwork in your home.
Additional Questions and Considerations
Do you already have a central heating system?
Many central air conditioning systems use the furnace blower to distribute cool air through the home. If you do not have a central heating system installed, it is cost-effective to install a heating and air conditioning (HVAC) system at the same time. If you already have central heat, you can use the existing fans and duct system for the central air system.
Do you need ductwork?
Although most new homes have ducts and vents already in place, many older homes have old convection heating systems or baseboard heaters without ductwork. In such cases, you will need to install ducts and vents to provide the air conditioning with a flow system. This would be the time to explore upgrading the existing heating system as well, as it will be much cheaper to do together.
How's the insulation in your home?
If your home is well built and well insulated, your heating and cooling systems will work more efficiently and save you money. If you have poor insulation, you will spend considerably more on utility bills. Explore the costs of new insulation or upgrading your old insulation as it might save you money in the long run.
Other Central Air Conditioning Facts
Need more information on air conditioning systems before you invest? While a cooling professional has all the know-how about these systems, here are some facts you should know going into the installation project.
BTUs and Air Conditioning Units
What is a British Thermal Unit? British Thermal Units or BTUs are defined as the amount of energy needed to cool or heat up one pound of water by a Fahrenheit. It's used to measure heating and air conditioning units in BTU/hour. Homeowners can determine what size air conditioner they need by following these steps:
Figure out the square footage of the room. For a square room, multiple length by width. For a triangular room, it's length by width and divide by 2.
There's a chart you can reference in stores that will tell you what size machine you will need. If you want a system for a whole house, it's a bit more complicated and will require professional assistance.
The rough estimates are as follows:
Area to be Cooled (sq. ft.)
Capacity (BTUs per hour)
700 - 1,000
1,000 - 1,200
1,200 - 1,400
1,400 - 1,500
1,500 - 2,000
2,000 - 2,500
What is Single-Stage vs. Two-Stage Cooling?
There are two kinds of air conditioning systems to choose from -- single-stage and two-stage. Your climate will determine which stage is best for your home.
Single-stage air conditioners turn on at full capacity when your home's indoor temperature rises past the set level on your thermostat. It then turns off completely until your house rises past that temperature again and repeats the process. This is good for climates that don't fluctuate much in temperature. In hot, humid climates with pulsing solar rays, the air conditioner will turn on often to compensate for the heat outside. This will lead to a lot of loud noises and an increase in your utility bill.
Two-stage air conditioners function at two-thirds or complete capacity, depending on the home's internal temperature. When your house rises above the preset temperature, it will turn on at two-thirds capacity and work its way to full capacity. Then, it will come down from full capacity to two-thirds capacity and shut off. This saves power and cools your home at the same time. It also reduces noise and emits cleaner air, which makes it the more efficient option for most homeowners.
The government offers tax credits to incentivize homeowners to purchase energy-efficient home products. Energy-efficient air conditioning units must meet standards set by the Consortium for Energy Efficiency (CEE).
To qualify for a tax credit from the federal government, you must save the manufacturer's certificate from your central air conditioning system. The IRS won't require the certificate at the time you file your federal tax forms, but they recommend keeping it with your records in case you are audited. It proves that you purchased a qualifying product.
Tax credits are offered for:
Split-system air conditioners ($300) -- must have 16 SEER or 13 EER
Packaged air conditioners ($300) -- must have 14 SEER or 12 EER
Determining Air Conditioning Unit Quality
When installing your air conditioning unit, ask the following questions to ensure its quality and optimum performance for years to come:
Is it sized correctly? The equipment must be the right size to provide the best air conditioner performance for your home. That's why professionals measure your home and do load calculations.
Is the duct system right for the air conditioning unit? Ducts that are damaged, leaking or missing some spots will affect the performance of your air conditioner. Your air conditioning contractor will repair and install more ducts, if needed, so everything works at its highest caliber.
How is the airflow? Airflow must be just right; otherwise, you could see an increase in your bill or hot spots in rooms of your home. A contractor can measure the volume and adjust ducts or vents for optimal airflow.
What about the refrigerant? Refrigerant is what cools the air flowing through your home while its liquid is consumed into the HVAC system. If there isn't enough, it could result in more energy consumed and more moisture in the air. The HVAC professional will check the charge of the refrigerant and adjust it if needed.
Central Air Conditioning Warranties
Any newly installed air conditioning unit will come with a manufacturer's warranty. The warranty's length will vary depending on the manufacturer. Warranties generally last from five to 15 years; it's safe to expect an average length of 10 years. The manufacturer's warranty covers the equipment and parts in the machine.
There is also the contractor's warranty, which covers the labor for repairs and additional work such as encasing the air conditioner in protective metal, wiring it to the home and so on. Products with indoor air quality (IAQ) modifiers have a separate warranty that's less than that of an air conditioner, so keep that in mind when investing in such products.
You may also invest in an extended warranty, which can cover:
Cost of replacement parts
Additional years for repair costs by a third party (i.e., no out of pocket expenses)
Coverage by the manufacturer
Extended warranties are expensive and generally cost more than maintenance. There are also strict limitations on the warranty that will likely require paying for repairs upfront and following up repeatedly for the reimbursement. You may also end up paying for a system you have replaced in less than 10 years if you move out of the home or upgrade.