A Complete Guide to the AC Installation Process

Installing a new air conditioning system is a very complicated process and involves many essential steps. A new AC is definitely not something you should install on your own, and the process should always be performed by a certified professional. If you’re looking to replace your existing AC or have a central air conditioning system installed in your home, here is a full overview of all of the steps involved so you have a better idea of what you can expect.

Planning and Inspection

The very first step is to inspect your home and your existing HVAC system and ductwork. This is important as it allows the technician to know exactly what work is needed. Modern AC units are bigger and more powerful than older units, and it may be necessary to enlarge the area that the unit sits on or move the new unit to a different location. You may also need to have your ductwork rerouted or new, larger ducts installed. If your ductwork is old or damaged and leaking, you will also need to first have the ducts repaired or replaced before your new AC can be installed.

The planning part of the process is also essential as it enables the technician to accurately calculate exactly what size of AC unit you need. Both oversized and undersized AC units won’t cool effectively and will also typically experience more frequent breakdowns and need more repairs. This makes it essential that you hire an experienced, certified technician that has the knowledge and experience to accurately calculate what size of AC unit you need.

Removing the Old AC Unit and Components

Once the planning process is completed and the new AC unit arrives, the next step is to remove the existing outdoor AC unit and all of the other system components. If you’re installing a central AC in a home that doesn’t currently have one, this step obviously won’t apply.

Whenever installing a new AC unit, it is essential that all of the system’s components are replaced. If not, the new unit may experience various issues and will likely not cool nearly as effectively as it should.

Before the outdoor AC unit or any other components can be disconnected and removed, the refrigerant must first be drained from the system. This is a legal requirement as discharging refrigerant into the air is unlawful. Whenever an AC unit is removed, the law requires that all of the refrigerant is recovered. The law also requires that this process be done by an EPA-certified technician.

After recovering the refrigerant, the old AC unit is then disconnected from the electrical system. Most homes have a disconnect box outside that is used to shut off power to the unit, and it is important that this disconnect and the wiring that leads from it to the AC unit are also replaced before installing the new unit. If your home doesn’t have a disconnect, the technicians will need to install one as this is required by building codes.

Once the outdoor unit has been removed, the technician will then need to uninstall the existing evaporator coil. This requires dismantling the supply plenum that leads to the air handler and then cutting the refrigerant lines and removing the evaporator coil. Finally, the technician will then need to remove the existing copper refrigerant lines if possible.

Preparing the Area for the New Unit

After the old unit has been removed, the technician will then need to prepare the area for the new unit. If the existing unit sat on a concrete pad, the pad should be removed or a new location chosen. Having the unit sit on a concrete pad is a poor choice as the concrete can settle or crack and cause the AC unit to become unbalanced, which can lead to numerous other issues. Instead, most contractors now use composite pads as they are more secure and will also better absorb vibrations to ensure the unit stays properly balanced. After leveling the area and laying down sand or gravel, the technicians will then install the composite pad.

Installing the Evaporator Coil

The next step is to install the new evaporator coil. The coil is installed above the furnace and needs to be far enough away so that the heat from the furnace can’t cause the drain pan underneath the coil to melt. The technician will first need to install rails inside the supply plenum, and the evaporator coil is then mounted to the rails.

If the supply plenum is larger or smaller than the hole on the evaporator coil, the plenum will need to be rebuilt so that the two are the same size. If the two aren’t the same size, the evaporator coil may freeze up because it doesn’t receive enough airflow, or too much air can flow around the coil instead of flowing through it.

Running the Refrigerant Lines

The next step is to run new refrigerant lines between the evaporator coil and the outdoor unit. A smaller copper line known as the liquid line runs from the outdoor unit to the evaporator coil, and a larger insulated line known as the suction line runs from the evaporator coil back to the outside unit. The copper lines come in a rolled coil up to 50 feet in length, and they are usually mounted close to the ductwork and attached to your home’s beams or floor joists. When installing the lines, it is important that they have as few bends and turns as possible, or else the refrigerant may flow too slowly and the system won’t cool as effectively.

The copper lines then need to be connected to the evaporator coil. A device known as a thermostatic expansion valve is also installed where the liquid line meets the evaporator coil. The expansion valve and the copper lines are connected by brazing, which is a special type of welding that allows two different types of metals to be connected. Brazing is done at extreme temperatures, so it is first necessary to protect any sensitive components so that they aren’t damaged by the heat.

After brazing the lines, the technician will then need to build the sheet metal cover or front of the plenum so that the evaporator coil is enclosed and the ductwork is airtight.

Installing and Connecting the Outdoor Unit

The final step is installing and connecting the outdoor unit. After the unit is mounted on the pad, the copper lines are then connected to the unit’s supply valves by brazing the two together. After installing the new disconnect box, the technician will then run the new power supply and connect it to the AC unit. Once everything has been installed and connected, the technician will then turn the power supply to your HVAC circuit back on so that they can then test to make sure everything is working properly and the system has no issues.

As you can see, there is a whole lot that goes into installing a new AC system. This makes it essential that you choose an experienced, reputable contractor and have all work performed by certified technicians. At Home Service Heroes, we specialize in AC installation. Our technicians will ensure that all work is performed properly, your new AC works just as it should, and your home is cooled effectively. We also offer AC repair and maintenance as well as heating, electrical, and plumbing services in Tampa. Give us a call today to schedule your appointment.