Why You (Probably) Can't Install an AC Unit Yourself

professional worker installing air conditioner outside
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If the thought of adding a chill vibe to your home is appealing, make sure you know what you’re in for before attempting to install a whole-house air conditioning system yourself.

Understand the System

For a whole-home system, you will likely choose between central air conditioning and a ductless or split system.

Central AC

For the most convenient and consistent cooling, you may want to invest in central air conditioning.

This can come in the form of a heat pump or be an add-on to your existing furnace.

Either way, you will have a separate unit either on the roof or near the foundation that draws, filters, and returns the cooled air to your home.

These units are exponentially more expensive, costing many thousands of dollars, in contrast to a few hundred for small units inside the home, such as window and portable AC units.

However, they are also highly efficient, convenient, and invisible indoors compared to the clunky and space-consuming portable or window options.

Central air is less efficient than more targeted methods of AC, due to the cost of pumping it through the system. It’s also less efficient in the fact that you’re paying to cool the entire space, when you may not need that much coverage.

However, central AC is by far the most convenient form of air conditioning.

To operate, it simply requires pushing a few buttons on the wall thermostat. It creates a temperature-controlled atmosphere throughout the house, without wide variations from one room to another.

outdoor air conditioning compressor

Ductless AC

If your home doesn’t have ductwork, air conditioning called ductless, or mini-split, systems can be installed. This type of system provides units inside the home in the rooms where they're needed, rather than a central system that is “hardwired” in.

However, the compressor and condenser unit remains outside like with the central air conditioning system, and in contrast to the self-contained window or portable units. The indoor portion contains the evaporator and fan.

Ductless units are mounted to the wall and basically work as a fan to blow the cooled air into the room.

Tubing connects the indoor and outdoor units and circulates refrigerant between them. There is no ductwork to install or maintain, which not only makes the job easier, but typically less expensive.

Not having air travel through ductwork also makes the unit more energy-efficient since there is less energy loss. Ductless air conditioners also eliminate the heat that often leaks in around window and portable units.

For individual spaces, ductless units offer an efficient way to cool without invasive installation. However, a single unit is not a cost effective or efficient way to cool an entire house.

You can install ductless units in several spaces throughout the home, each connecting to the compressor outdoors. As a system, it adequately cools a larger space.

There are several other advantages to a split, or ductless, AC. For example, the unit itself doesn’t have to be removed during the winter, like most portable and window units.

In fact, they’re quite weather-resistant so there’s no need to worry when it rains or snows.

Another advantage of a split unit AC system is you can create zones within your home. This significantly increases efficiency. Rather than paying for the central AC to pump through the entire house, a ductless AC unit can be turned on in a single space for targeted cooling.

Energy Consumption and Savings

Either type of system is much more energy consumptive than relying on passive cooling techniques alone. However, replacing an old system with a new system will save you energy and money.

Do your research when choosing an AC unit for the best long-term energy and cost savings over the lifetime of the unit. It pays to pay a bit extra for energy efficiency up front.

Planning and Paperwork

Taking on any DIY project requires taking on aspects a professional would tackle if you hired them instead. In the case of AC unit installation, that includes paperwork with the city or county in the form of permits each step along the way.

You may need permits to place your AC unit on a roof or to ensure you’re following regulations when it comes to pouring a concrete pad alongside the house.

In addition, the planning can be very comprehensive for a whole-house AC installation. You’ll need to understand the electrical schematics, know what’s behind your walls, and be able to create a realistic time estimate for the project.

What Size AC Do You Need for Your Space?

A professional can easily identify the type and size of unit you’ll need in your space. If you choose to tackle the project yourself, you’ll also be on your own to hunt down the right AC unit that will be most efficient to cool the square footage and layout of your home.

There are several ways to go about this. The basic calculation is to take the square footage of your home times 20. Therefore, a 2,000-square-foot home would require a 40,000 BTU AC.

However, the actual recommendation is a 3-3.5 ton unit for that size of home. A three-ton unit equates to 36,000 BTUs (tons x 12,000) and a 3.5-ton unit comes in at 42,000 BTUs, so the original estimate falls in the middle. That’s why it’s best to at least consult with a professional about the specific needs of your home.

If you’re unfamiliar with the term, BTU stands for British Thermal Units and acts as a measure of the air conditioner’s cooling capability. BTUs range from around 5,000 to 12,000. The lower the number, the smaller the space it will effectively cool.

If you’re going to invest in central air conditioning, make sure the unit you choose will be robust enough to handle the job.

Cost of Installing Central Air Conditioning

Costs vary widely for installing central air conditioning, depending on many factors.

These include the type of unit you install, whether you’re installing the unit on the roof or on the side of the home, whether you already have ductwork in place or you need to install it yourself, and whether you need to expand the electrical panel to accommodate the air conditioning.

The cost of the unit will range from $1,500 to $5,500. If you already have ductwork in place, the total cost for a unit and professional installation would run between $3,800-$7,500, but could go as high as $12,000.

Cost of Installing Split System Air Conditioning

worker installing split air conditioner

Since installing ducts adds $500-$2,100 to your installation bill (if hiring a professional), installing a split-system is a more budget-friendly option.

However, the costs for a split system can be as high or higher than central AC with the most basic units running between $1,300-$5000 and installation costing an average of $300-$1,500.

The SEER rating, brand, and size you choose can make a big difference in price, as well as how many zones you’re planning for. Those factors create a huge variance in the installed price ranging from $2,000 to $18,000.

Replacement vs Installation

The scope of your project will be considerably different depending on whether you're replacing an existing unit, installing a new unit with ductwork in place, installing a ductless unit, or doing the installation during the construction of the home rather than a retrofit.

All these factors will affect the cost, timeline, and complexity of the project.

The Challenges of Installing AC Ductwork

worker installing air conditioner duct

In new construction, ductwork is fairly easy to incorporate into the plan. From the planning stages, it’s just a matter of actually mounting and connecting the ducts and vents.

However, if your existing home doesn’t have a ductwork system, adding one is a comprehensive endeavor. You’ll need to create a map outlining the ductwork system.

It may travel through the attic or beneath the house. It will most certainly need to be installed within the walls too. That means removing existing drywall or other wall covering, completing the installation, and reinstalling the wallboards when you’re done.

If you’ve ever dabbled in sheetrock installation, you’ll know this is no small feat.

The Challenges of Installing AC Vents

Vents can also be incredibly tricky. You’ll need to create openings to meet up with the ductwork. This might mean cutting through flooring and subflooring or slicing through ceiling materials.

You might also be installing them on the top of walls or in closets. Consider how you will put vents in a concrete basement and how you’ll map it if you don’t have an attic.

The Challenges of Electrical Work

worker installing AC electronics

Electrical work can be very basic or ‘shockingly’ complex. The primary electrical issue with installing air conditioning units is figuring out how to safely and effectively connect the unit to the central electrical box.

You’ll need to dedicate a circuit to the AC unit or units. If your circuit breaker panel doesn’t have enough room you may need to expand to a second breaker box to accommodate the new load.

Plus, remember everything needs to meet code requirements and pass inspections.

The Challenges of Prepping for AC Installation

It’s easy to be idealistic during the planning stages, but you may need to make significant modifications to accommodate the unit on the roof. Plus, how will you get the unit onto the roof?

You’ll likely need permits and to pass inspections before you can even install the main unit. The same holds true if you’re pouring a concrete pad where you’ll place the unit.

The Challenges of Dealing with Refrigerant

worker with coolant gauge working on AC

Check your local and national regulations in regards to refrigerant handling. You may need a professional to tackle the removal of an old AC unit.

You may also need to meet requirements when installing a new unit. It might even require you to earn EPA certification if you plan to tackle it yourself. This involves an exam and a fee.

Challenges in Buying an AC Unit

While you can likely find a unit locally, you may find yourself falling into the depths of the internet to locate your preferred air conditioning unit. Then you’ll need to wait for delivery and pay the associated fees.

It’s worth noting AC units will almost always cost less when purchasing through an established AC installation company since they can buy in bulk and have discounts arranged with vendors.

Although you’ll pay more for the unit on your own, you will save if you choose DIY installation.

Challenges in Positioning an AC Unit

Again, you’ll need to do your research here. AC units need to be close enough to the home to tap into the electrical system. Yet, they need to be installed with proper airflow around the unit. You’ll need to consider the noise factor and ensure the unit doesn’t block access routes around the home.

Pros and Cons of Hiring Professionals to Install AC

worker installing outdoor AC unit

We’ve talked about some of the differences between hiring a professional or tackling AC installation DIY style, but there’s more to consider.

Obviously the cost difference is significant. However, do remember a DIY installation will take longer than a professional job and that may cost you time off work.

The project will go faster and more efficiently if you go with the pros too. They’ll be in charge of orders, timelines, planning, and obtaining permits.

Plus, a professional installation typically includes a warranty and a maintenance program for a few years following installation.

However, there’s nothing like the sense of accomplishment when you take on a challenging DIY task and succeed. Depending on the complexity of your installation, it may be something you can handle relatively easily and feel good about while you enjoy the cool breeze.

Be realistic about the scope of the project, as well as your skill level, when making your decision.

Required Maintenance and Lifespan of Air Conditioning

The primary maintenance required for your home’s air conditioning is to ensure each unit’s filters are changed or cleaned regularly.

Beyond that, you may need to clean the coil, repair bent fins, and verify drains are working properly. A modern, well-maintained air conditioning unit will last around 15-20 years.

Do-it-yourself central air conditioning installation is a project that requires advanced planning, safety, and home improvement skills.

It’s not the easiest first-timer DIY project out there, but that’s not to say it’s not for you. Evaluate your own skills to decide if it’s a reasonable task or if you fall into the majority of people who should hire a pro instead.

Find out more About Ductless Air Conditioning and review this Maintenance Checklist for Air Conditioning Ductwork to further expand your knowledge on the topic.