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HVAC

Central Air Conditioning Installation and Repairs

On this page:
  • How does a central air conditioner work?
  • How to prepare for central AC installation.
  • Central AC installation and maintenance.

Find the best HVAC contractors in your area.

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Central Air Conditioners Installation Guide

Your home’s central air conditioning system is a critical component when it comes to cooling your home and being comfortable. Understanding how a new central air conditioner works, what to expect with the installation process, factors that may affect your purchase, and how to hire a qualified contractor are all essential to getting the best return on your home investment.

How Does a Central AC Unit Work?

A central air conditioning (AC) unit installation connects a new AC unit to a home’s duct system to cool your home. It is often paired with a heating system such as a furnace to fully regulate your home’s cooling and heating efforts for the perfect temperature across the entire home.

A home air conditioner unit comprises three main components: a condenser, a compressor, and an evaporator. The condenser and compressor reside on the exterior of your home and are usually installed on a small, concrete slab where they are easily accessible. The evaporator, including the evaporator coil and air handler or air blower, is located inside the home in a closet dedicated to the unit or attic. In homes where a furnace is used, the evaporator will reside above it where it connects to the plenum or a duct junction for air distribution. how hvac works - central air conditioner - illustration

If you do not have a furnace or other heating source, your central air conditioning system may be equipped with an electrical resistance heating element to provide your home with warm air during the winter months. Since we are talking about a central air conditioner, this article will focus mainly on the cooling aspects of an HVAC system. 

In either case, a central air conditioning system falls under the forced central air distribution category, meaning the same ductwork, motor, and blower are used for both heating and cooling your home. Once the unit is activated, hot air is drawn from the house into the return air vent and pulled across the evaporator coil to cool it. The fan and blower assembly provide the circulation to draw in and distribute the conditioned air through the ductwork to cool the house. You can read about the specifics of how air conditioners work here.

Which Homes Are Best For a Central AC Unit?

Here are a few factors to consider when deciding if an AC unit is right for your home.

Home Age

Depending on where you live, most homes built after the late 1960s included the infrastructure for central cooling. If you have an older home that does not include ductwork and the proper piping and electrical requirements, installing them will add time, complexity, and costs to the project. 

Size and Layout

Larger homes and two-story homes where heat rises are good candidates for central air conditioning. Use our air conditioner size calculator to determine the right size for your home.

A smaller home with an open-plan style layout may already enjoy adequate cooling from cross-ventilation. Another type of central air or cooling system may be a better and more cost-effective option.

Region

Some cooling systems are more prevalent in different climates. For example, homes in areas with milder summers may be able to stay cool with an attic fan, AC heat pump, or another cooling system. In desert areas, evaporative coolers are a popular and energy-efficient option. Your HVAC contractor can help you select the best cooling solution for your home and household.

When To Plan AC Installation

Your Space Is Not Adequately Cooled

The cooling capability of air conditioners is often affected by dust accumulation in the air condenser, filters, and coils. All these parts can be cleaned easily without any outside help. If your home still isn’t cool enough after cleaning, contact an HVAC contractor to check any equipment failures and to determine if you simply need repairs or a full replacement.

Mechanical Problem With the Unit

There can be several reasons why your AC unit is not working. These can be mechanical or technical issues with the unit that only a seasoned HVAC contractor can help with.

Time of Year

Spring is a good time to get your new AC unit installed or to repair an old unit. Warmer weather makes the installation process easier for contractors since they would be working on both the outside and inside units of the air conditioner. It is also before the hot summer months when many HVAC professionals are busiest so you will probably not have to wait as long to schedule your installation.

When Your Budget Allows

A home air conditioner replacement is not the most expensive home improvement project, but the cost can be significant, especially if it is unplanned. The average cost to replace an AC unit ranges from $6,465 to $11,877. Use the Modernize cost calculator for more detailed pricing estimates for your needs.

What Happens During AC Installation?

Either a licensed HVAC contractor or technician is recommended for a professional and worry-free installation. More details about what to look for in an HVAC contractor is below. 

It takes between four and eight hours to replace an AC unit. If you are installing central air conditioning for the first time, plan on an additional two to four days for ductwork installation.

Here are the steps for a central air conditioning replacement:

  1. Removal and disposal of the existing AC unit.
  2. Inspection of ductwork, electrical connections, and piping to determine if anything needs to be repaired or replaced.
  3. Installation of new AC unit and addition of refrigerant.
  4. Addition of refrigerant .
  5. Testing and inspection to ensure the new unit works properly.
  6. Installation of a new thermostat if needed.
  7. Final inspection.

Hiring a Central Air Installation Contractor

Hiring a reliable local HVAC installer is an important part of your project. Central air conditioners require a high degree of training, knowledge, and experience to properly install. Both of the system’s main components — the evaporator and the condenser — are sealed units, and special training and tools are required to service them.

Choosing the right central air conditioning contractor is as important as choosing the best HVAC system. Before hiring an HVAC contractor, verify your contractor is licensed and insured to perform the work and to replace refrigerant (a requirement of the Environmental Protection Agency). Selecting a professional who is accredited by Air Conditioning Contractors of America (ACCA) is also a good practice, as they are trained in the most current methods and ANSI standards. If you want Modernize to find an HVAC pro for you, we vet all of our contractors so that you don’t have to.

The Better Business Bureau (BBB) is another great place to vet your contractor, as they will have any complaints, lawsuits, or concerns on file regarding the applicable HVAC contractor. Online reviews are also helpful in determining if your central AC contractor is a great choice.

Click on our full checklist for hiring an HVAC contractor and questions to ask before making your decision. 

How To Prepare for Your Central AC Unit Installation

As you get ready for your AC installation, there are a few things you can do to ensure you are getting the best return on your investment.

Use our step-by-step guide on exactly what you should expect with an HVAC installation from start to finish.

Air conditioning outside unit in backyard

Central HVAC Maintenance

The benefits of annual preventive central air conditioner maintenance checkups on your central air-conditioning system far outweigh the costs of repair service. With regular preventive maintenance checkups, you can expect:

  • Peak performance from your central air conditioning system when you need it most (No one wants their system to malfunction in August).
  • Increased energy efficiency, as a finely tuned and maintained unit will consume less energy, reducing your energy costs.
  • Early warning of potential equipment failures in the future.
  • Peace of mind knowing your home’s central air conditioning system is in A1 condition and using energy efficiently to save on monthly energy bills.
  • You will also want to have your AC coils cleaned regularly, which can be done on your own.

Good maintenance habits can lead to long-term air conditioning savings for your home, as ensuring your system is properly functioning year-round can significantly reduce energy and utility bills.

Other Types of Central Air

  • Split Air Conditioning Systems. Split AC systems usually refer to a ductless air conditioner. Also called a mini-split system, this dual central system combines both an outside and inside AC unit to keep a comfortable temperature in your home.
  • Heat Pump Split AC Units. A ductless AC heat pump system is a type of split system AC unit that works well with hotter climates. It works by pumping heat out from the inside of your home to the outdoors. In cold climates, it will pump hot air into your home from outside to regulate temperature. Heat pump installations are cheaper, but are best for areas without extremely cold winter climates.
  • AC Window Units. These are the most simple central air systems and can be installed in a regular window to cool a small area of a home.
  • Portable Air Conditioners. These air conditioning units are an evaporative HVAC system that can be moved around your home utilizing a split or hose system to make temperatures more comfortable.
  • Evaporative Coolers. An evaporative cooler or swamp cooler cools warm exterior air into the home by passing it through water-soaked pads. The water quickly evaporates into the air and lowers its temperature.  
  • Whole House Fans. Typically installed in attics, whole house fans work by drawing in cool air from open windows and pushing warm air up into attic vents and out of the home.

types of central air conditioner units

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