Central Air Conditioning Installation: How To Do It Yourself

Central Air Conditioning Installation: How To Do It Yourself

Anthony Barnes

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If you live in a warm climate then it is important to keep your home nice and cool.

If your home is too warm and humid then it will make your living environment very uncomfortable. You could find yourself getting easily irritated, and struggling with lethargy and a lack of energy.

One of the best ways to keep your home cool is by having a central air conditioning system installed. This will ensure that the air circulating around your home is cool rather than warm.

The only issue with this is that the installation costs for an air conditioning system are quite expensive. But what if you could do it yourself?

We have put together this guide to tell you everything you need to know about installing a central air conditioning system.

This will help you to decide whether it is something you feel confident doing or whether you need to pay the installation fees. Keep reading to find out more.

What Is Air Conditioning?

What Is Air Conditioning

Air conditioners are devices that remove heat from the air. They work by using refrigerant gas which absorbs heat from the surrounding air.

When the air passes through the condenser coil, the heat is removed from the refrigerant gas.

It is then passed into the evaporator coil where it changes state back to liquid form. As the air passes over the evaporator coil, it picks up the heat from the coils and carries it away as cold air.

A single air conditioning unit will cool one room in the house, whereas an air conditioning system will cool the whole house. This is why they are more complex to install.

Why Install An Air Conditioner?

Installing an air conditioning unit can be beneficial to your home because it allows you to control the temperature inside your house.

In warmer climates, this means keeping the interior of your home cooler and comfortable.

If you live in colder areas then you may want to use the air conditioning to keep your house at a constant temperature. Either way, installing an air conditioning system can be beneficial.

What Are The Different Types Of Central Air Conditioning?

If you are considering installing central air conditioning in your home then you have two options to choose from – a unit packaged system or a split system.

A unit packaged system is installed to the outside of your home and can also be converted into a heating system if you add the right coils or you also install a furnace.

The split system has an indoor unit and an outdoor unit that are connected with refrigerant lines.

What Are Air Conditioning Ducts?

An air conditioning system cools your entire house rather than just one room. It does this using a series of air ducts that are installed throughout the home.

If your house has previously had central air conditioning units then there may already be a system of ducts in place, which will make the installation process a lot easier.

It is more simple to replace an old air conditioning unit with a new one than it is to install one from scratch.

If your home has no air ducts then this is quite a significant job that requires a lot of DIY and renovation.

Should You Install The Central Air Conditioning Yourself?

Should You Install The Central Air Conditioning Yourself?

As with any big decision about home improvement, there are some benefits and some downsides to choosing to do it yourself rather than hiring a professional.

You will need to weigh up the pros and cons before you make your choice.

What Are The Benefits Of Doing It Yourself?

There are two main advantages if you decide to install the central air conditioning (see also ‘Top 10 Benefits Of Air Conditioning‘) yourself:


Hiring a professional to install your air conditioning is expensive. The labor costs are high and there will be additional fees such as preparatory tasks that could inflate the cost.

You have less control over the final cost of the project, as the professionals could add additional charges for ‘unforeseen issues’.


If you hire a professional then you need to spend time doing some research to find a company that you can trust.

This is time-consuming as you will need to read customer reviews and try to get recommendations from friends and family.

If you make the wrong choice then you could end up with an unreliable company that adds lots of extra charges, causes unnecessary delays, and does a bad job.


If you take on the project yourself then you will be learning a new skill, and by the time you have finished, you will have the satisfaction of accomplishing a challenging task.


If you are in charge of the project yourself then you have more freedom to choose what you want, where you want it, and how you would like it to be done.

You can pick whatever brand of air conditioning you prefer rather than using the recommended brand of the professional installer.

What Are The Downsides Of Doing It Yourself?

With a big job like this, there are some risks and potential issues with deciding to take it on yourself:

Manual Labor

This kind of job is labor-intensive and requires a lot of hard work. If you decide not to hire a professional then you will need to do this yourself.

You might be able to get some help from friends and family, but you will be taking the brunt of the labor.


A professional will be very experienced with this kind of job and will be able to work on it continuously until it is finished.

This means they will be able to do it quickly. It will likely take you longer as you will be learning as you go.

You will also be trying to find time to do the work in between your normal job and any other duties you have such as childcare, cooking, and cleaning. This could cause the job to take a long time to complete.


Most home improvements require some kind of permit. A lot of professional services include the admin and the applications for this in their quote and as part of their service.

If you are doing the installation yourself then you will be responsible for all of the paperwork.


If you get a professional to install the air conditioning then they will be responsible for any issues or errors. Any liability for rectification work will fall on them.

They will often provide some kind of ongoing maintenance plan which means that you don’t have to worry so much about the upkeep of the central air conditioning (see also ‘Central Air Vs. Mini Split‘).

If you do the job yourself then you will be responsible for all of this.

Tools And Materials

Whilst you won’t have to pay the labor costs of installing the central air conditioning, you will still need to buy all of the necessary tools and materials. This could end up costing more than you realize.


Depending on where you live, you might need to be certified to install an air conditioning system (see also ‘ The Pros And Cons Of High Velocity Air Conditioning Systems ‘).

This means that you will need to attend a class or do online research and then sit an exam before you can start your project. There will be a cost involved with this.

How Do You Install Central Air Conditioning Yourself?

How Do You Install Central Air Conditioning Yourself?

If you have considered the pros and the cons of taking on this project yourself and you have decided to give it a try, then here are the steps you need to follow.

Step One: Choose Your Air Conditioning Unit

The first step in installing central air conditioning is to choose which air conditioning unit you are going to use.

We recommend doing some research online to see which one is likely to be best suited to you and your home.

Remember to consider the size of your home and your local climate, and compare this to the specifications of each product to ensure you choose one that is going to work well for you.

Read customer reviews to see what people who have used the product have to say about it.

When you are setting yourself a budget for an air conditioning unit, you will need to consider the upfront cost of the unit as well as the ongoing cost of running it.

The more energy-efficient units cost more upfront but will save you money in the long term.

When it comes to purchasing your air conditioning unit, remember that it may not always be cheaper to buy it online due to shipping costs.

Compare the prices with your local home improvement or hardware stores and see which is best.

A local store may even be able to provide you with more advice on which product will be best.

If you are looking to save yourself some money then you could buy a second-hand air conditioning unit. However, it will not last you as long and you will need to check that it is in good condition.

If you can afford a new unit then this is the best option.

Step Two: Choose A Location To Install Your Unit

If you have a split system then it will come with two units – one for inside the house and one for outside.

If you have a single system then it will come with one unit that goes outside. Either way, you will need to decide where to put the outside unit.

You need to choose an area that has a good flow of air.

Make sure the air conditioning unit is out of the way so it will not get damaged when you are using the outdoor areas of your home (if you play basketball in the yard then don’t install the unit in a place where it could get hit with the ball).

It should also be out of sight so that it doesn’t get stolen. However, it needs to be accessible so that you can carry out maintenance and repairs when needed.

You also need to consider the position of the outside unit in relation to the electric panel and the interior unit, as all of these elements will need to be connected.

You will also need to check your local regulations in terms of how far away the air conditioning unit needs to be from gas meters, water meters, and supply lines.

The noise level of the unit may play a part in where you choose to place it. A quieter unit can go in lots of places but you won’t want a noisy unit close to a window or a door.

Step Three: Inspect The Ducts

If your home does not have air ducts already installed then you will need to get a professional to do this for you.

Speak to your contractor about the best places to install the duct work to avoid having to make lots of holes in the drywall.

If your house is being newly built then the ducts can be added before the drywall goes in. If you are particularly skilled with home renovations then you might be able to add the duct work in yourself.

If there is ductwork already in place in your home then you will need to inspect it before you install your new air conditioning unit.

Make sure that there are no cracks in the ducts or large gaps where air can escape, as this will make your air conditioning unit work harder than it needs to.

You should also ensure that the ducts are fixed firmly in place and are not sagging. Replace any damaged ducts if necessary.

Step Four: Remove The Old Unit

Before you can install your new air conditioning unit, the old one will need to be removed. Check the model of the old unit and research online how it needs to be disposed of.

Due to the refrigerant material, it is not usually as simple as taking it to a landfill. You might need a certified professional with a license to dispose of hazardous waste.

Step Five: Install The New Unit

Once you have completed steps one to four, you will be ready to install the new air conditioning unit. Read the instruction booklet for your chosen unit very carefully before you begin.

Start by securing the outside unit in your chosen location, making sure it is firmly attached. If you have a split system you will then need to install the inside unit.

The evaporator coil will need to go inside the furnace plenum which is found either side of the air handler.

Measure the distance between the two units and figure out how much refrigerant line you will need to connect them, along with the accompanying drain piping.

The refrigerant line is usually made from copper.

Make sure that you are happy with the route that the pipes will be taking, and if you have concerns then raise them with a contractor.

Make sure that the place where the pipes go from the inner wall to the outer wall is sealed well to prevent water from getting into the system.

Once these pipes have been attached, you can install the thermostat and the electrical lines that bring power to the system. The thermostat will be connected to the furnace using a low voltage wire.

You will also need to add an auto shut off for the condenser unit which will run to the electrical service panel.

Make sure that your service panel has enough capacity to handle this, or else you will need to upgrade it to prevent an overload.

Finally, get rid of any contaminants in the refrigeration lines. You will need to install a condensate drain line to ensure that any built up moisture can always be easily removed from the system.

The pipe will either run to the floor drain of the basement or to a waste water pipe on the outside of the house.

Step Seven: Check That The Central Air Conditioning Is Working

Once you have completed step five and the new system has been installed, you will need to make sure that it is working properly.

The instruction booklet for your unit should have a detailed section on checking the system.

You will need to turn the central air conditioning on and then check every duct to make sure that the air is flowing freely.

Adjust the thermostat and make sure that the air conditioning unit responds accordingly.

Step Eight: Maintenance

To prevent any future problems with your central air conditioning, you will need to perform regular maintenance to keep it running smoothly.

Some common issues with air conditioning units include leaking refrigerants, electrical faults, and damaged air ducts.

Keep an eye out for things like this, and periodically check the units over for signs of damage or fault.

The more consistent you are with the maintenance of your air conditioning unit, the longer it will last you.

Air conditioning units tend to be used seasonally, so you can time your in-depth checks and service of the units for the beginning and the end of the warm season.


Installing your central air conditioning (see also ‘How Much To Install Central Air With Ductwork‘) is quite a challenging task. It will save you money but there are also some downsides to taking on the project.

If you feel confident enough to do it yourself then ensure you follow our guide to help you do it correctly.

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By Anthony Barnes

Anthony Barnes is the founder of Water Heater Hub and a second-generation plumber by profession. Before developing Water Heater Hub, Anthony Barnes was a full-time plumber, and he has undertaken a wide variety of projects over the decades. As a second-generation plumber, it was easy for Anthony to get used to the technicalities of all from a tender age