Many homeowners don’t realize how complicated the process for installing an HVAC system can be. It is usually not recommended that a person attempts HVAC installation on their own, so hiring a professional is your best bet. In this guide we’ll be exploring the HVAC installation process and what to expect during.

Inspecting Your Existing System

In the case that you are simply replacing your existing HVAC system, the professional that you have hired will come and inspect the system and its area to get an idea of what to expect on installation day. They likely already have an idea from any consultations they did previously, but this is a good time to see anything they may have missed before. 

Preparing Your Home Beforehand

It is a good idea to clear the area that you know HVAC professionals will be in of any delicate or sentimental items. Oftentimes, contractors prefer not to move these items themselves, as they don’t want to be liable in case something happens. 

You could always cover up furniture that can’t be moved as easily (such as couches) so they don’t get covered in any debris during the installation process. 

When the contractors are in your home for installation, they will bring drop cloths to put around your home to protect your flooring and furniture.

Conducting Safety Measures

On installation day, your contractor will make sure that they turn off anything that is connected to your unit. For example, they will turn off the electricity or gas valves before starting with the installation process.

Removing the Existing Unit

Your previous AC unit will have more refrigerant remaining in it that must be removed before the unit itself can be removed. According to the Environmental Protection Agency (EPA), a certification is required to handle refrigerant as well as devices that contain it. It is also required to dispose of the refrigerant in what is called a recovery machine.

Once this process has been done properly and safely, the electrical wiring from the unit will be removed next. The HVAC contractor will remove the wiring from a disconnect box near your old unit. Some old units do not have disconnect boxes, and in this scenario, a disconnect box would be installed.

Removing Other Equipment

The indoor evaporator coil and copper line set will also need to be replaced. The evaporator coil is the other half of your AC unit. The other end of your refrigerant lines are connected to this. It can either be above or below the furnace. Before removing the coil, a sheet metal plenum must be removed first. 

Sometimes it is difficult to remove these items when there is open access to it. For example, if your coil is in a closet or finished basement. Keep in mind that you may see additional costs if the coil is difficult to remove.

The copper line set is what carries refrigerant and oil to an outdoor unit back into the evaporator coil. These lines could be in a number of places: under the floor, in concrete, underground, or in a ceiling. The oil in the copper line set in old units cannot be mixed with new oil, so it is recommended to replace the entire set. Sometimes, though, it is not possible to replace the set, but in those situations the lines would be flushed.

Preparing the New Unit

This varies depending on whether you are installing an outdoor or indoor unit. With outdoor units, there is a possibility that there would be obstructions from shrubbery if the new unit is bigger than your previous one, so those would need to be removed. The ground may also need to be leveled. Then the rest of the unit installation will begin.

With indoor units, the outdoor preparation is obviously not necessary, so the process picks up from disconnecting ductwork, wiring, and valves. 

The Actual Installation Process

Here is a brief overview of how the installation process looks from here.

  • New ductwork is installed.
    • These connections will be sealed so you can have the most efficient system possible.
  • New lines and wiring are installed.
    • A high voltage line will be installed, then the toggle switch will be replaced. The control wiring will be changed. The exhaust will be reworked as well as checking the vent flue. If necessary, the gas line will be reworked as well. 
  • Any existing lines will be cleaned, as well as replacing filters and insulation if it is necessary.
  • At this point, they will check how the system is running and check for leaks by running nitrogen through the system.
  • Refrigerant and service valves are added.

Final Thoughts

We hope that this overview of the installation process helps you understand what to expect when hiring an HVAC professional for a new installation. If you are still unsure about a part of the process, we would love to answer any questions that you have.