Most homeowners never see what actually happens during an air conditioning installation. A crew arrives, works for several hours, and eventually lets you know the new system is up and running. But a lot is happening between those two moments, and every step in that process determines how well your system performs and how long it lasts.
Understanding what installating an AC unit involves helps you ask the right questions, recognize quality work, and spot shortcuts when they are being taken. On the Northshore, where your air conditioner runs hard from April through October and humidity is a persistent challenge all year long, the installation is the foundation everything else is built on.
Here is a complete walkthrough of what a professional AC installation should look like from start to finish.
Step 1: The In-Home Estimate and Load Calculation
A proper installation starts well before any equipment arrives at your home. During the estimate visit, a technician evaluates your home and gathers the information needed to recommend the right system.
The most important part of this visit is the Manual J Load Calculation. This calculation accounts for your home’s square footage, ceiling height, insulation levels, window size and placement, and how much sun exposure your home receives. The result tells the technician exactly how much cooling capacity your home requires.
On the Northshore, this step is especially critical because of humidity. An oversized system cools your home too quickly and shuts off before completing a full humidity removal cycle. Your rooms reach the set temperature but stay damp and muggy, a common complaint in homes with oversized equipment in this climate. An undersized system runs continuously and still struggles on the hottest days in July and August.
Any contractor who recommends a system size without first performing a load calculation is guessing, and that guess follows you for the life of the system.
Step 2: Arrival, Review, and Setup
On installation day, the crew will contact you before arriving. When the team gets to your home, the lead technician will walk you through everything that will be done before any work begins. This is your chance to ask questions and make sure both sides have the same understanding of the scope of work.
While you are reviewing the plan, the rest of the crew begins laying down floor protection throughout the home and staging tools and materials. The existing system is powered down safely, with electrical circuits and any gas supply lines shut off before anyone touches the old equipment.
Step 3: Refrigerant Recovery and Old Equipment Removal
Your existing outdoor condenser contains refrigerant that must be recovered before the unit can be disconnected. Federal law requires this refrigerant to be captured using a certified recovery machine and a sealed recovery tank. It cannot be released into the air. Every technician who handles refrigerant must hold an individual EPA Section 608 certification.
Once the refrigerant is recovered, the outdoor unit is disconnected from its wiring and refrigerant lines and removed. The indoor evaporator coil, which sits above or below your air handler, is also removed at this stage.
Step 4: Preparing the Installation Area
Modern air conditioning equipment is physically larger than older models. The pad your old condenser rested on may need to be replaced or re-leveled before the new unit can be set. A composite pad is the right material for this application. It holds up in outdoor conditions for the life of the system and absorbs vibration better than a concrete slab, which can crack and shift over time.
The technician will also confirm that the new unit fits properly in its location and meets the clearance requirements specified by the manufacturer and local code.
Step 5: Installing the New Indoor Evaporator Coil
The indoor evaporator coil must be replaced at the same time as the outdoor condenser. Installing a new outdoor unit with an old indoor coil reduces efficiency, creates refrigerant compatibility risks, and almost always voids the warranty on the new equipment.
The coil is connected to the sheet metal plenum and sealed tightly to prevent conditioned air from leaking into unconditioned spaces before it reaches your rooms. A condensate drain line is attached to carry the moisture your system removes from the air to a drain or condensate pump. This line must be pitched correctly, glued at all joints, and fitted with a safety overflow switch that shuts the system down if the drain becomes blocked.
A well-maintained air handler contributes to proper installation results. If it has been a while since your system received a thorough AC maintenance visit, this is a good time to ask about the condition of your air handler and ductwork before the new coil goes in.
Step 6: Running New Refrigerant Lines
The copper refrigerant lines connect the indoor coil to the outdoor condenser. These should be replaced along with the equipment whenever possible. Old refrigerant lines can contain oil that is incompatible with newer refrigerant types, causing internal damage if the lines are reused without proper flushing.
New lines are run as straight as practical, supported every four to six feet, and protected where they pass through walls or contact other materials. A filter drier is installed in the line set to remove any moisture that could contaminate the refrigerant circuit.
The connections at both the indoor coil and the outdoor condenser are brazed, a high-temperature welding process that creates tight, leak-free joints. Dry nitrogen is purged through the lines during brazing to prevent oxidation inside the copper tubing. After brazing is complete, the system is pressure-tested with nitrogen to confirm there are no leaks before refrigerant is introduced.
Step 7: Evacuation and Refrigerant Charging
Evacuation is one of the most critical steps and one of the most commonly skipped or rushed by installers cutting corners. A vacuum pump removes air, moisture, and any other contaminants from the refrigerant lines and indoor coil. The system must reach a vacuum level of 500 microns or lower and hold that level for a defined period before refrigerant can be charged.
Moisture left in the system reacts with refrigerant oil and forms acids that damage internal components over time. A system that was not properly evacuated may run well for a year or two before the damage shows up as a premature compressor failure or a developing refrigerant leak.
Once the vacuum is verified and holds, refrigerant is charged into the system. The charge is measured and adjusted to match the manufacturer’s specifications based on real-time pressure and temperature readings.
Step 8: Electrical Connections
The outdoor condenser requires a dedicated electrical circuit and a service disconnect box mounted nearby. A proper installation replaces the disconnect box and the electrical whip that connects it to the unit. These components protect the system and provide a safe way to cut power during future service calls.
Control wiring that allows your thermostat to communicate with the system is also connected at this stage. If your electrical panel is older or already fully loaded, it may need updates to accommodate the new system’s circuit requirements. Electrical updates are a normal part of many installations and typically add $100 to $600 to the total project cost.
If your existing thermostat is not compatible with the new equipment, this is also when a new one is installed. A smart home thermostat installed at the same time as a new system is one of the easiest ways to maximize the efficiency and comfort the new equipment can deliver.
Step 9: Startup and Commissioning
Once everything is connected, the system is turned on and allowed to run for 15 to 20 minutes. During that time, the technician takes a complete set of measurements to confirm the system is operating within the manufacturer’s specifications.
Those measurements include:
- Suction and liquid line pressures and temperatures
- Superheat and subcooling values
- Indoor and outdoor ambient temperature readings
- Return and supply air temperature differential
- Static pressure throughout the duct system
- Amperage on the compressor, outdoor fan motor, and indoor blower motor
- Total refrigerant charge verification
This commissioning process is the only way to confirm the system is actually performing correctly rather than simply running. A properly commissioned system has a documented baseline that future technicians can compare against. Installers who turn the unit on, confirm cold air is coming out, and leave have skipped this step, which matters.
Step 10: Cleanup and Final Walkthrough
When the work is complete, all old equipment, scrap materials, and debris are removed from your property. Floor protection is the last thing rolled up so any mess stays contained. Your home should look exactly as it did before the crew arrived.
The lead technician will walk you through what was done, show you how to operate the new system and thermostat, and go over the warranty details. If you have questions about maintenance schedules or our Shield of Protection plan, this is the right time to ask.
How Long Does an AC Installation Take on the Northshore?
A standard residential replacement typically takes four to eight hours. Jobs that require ductwork modifications, electrical panel work, or difficult access to indoor equipment can take longer. Your technician will give you a specific estimate once the home has been evaluated.
Does AC Installation Require a Permit in Louisiana?
Yes. Every new AC installation in Louisiana requires a permit. The permit process ensures the work meets safety codes and creates an official record tied to the property. Any contractor who suggests skipping the permit to save time or money is not operating correctly, and that shortcut can create complications if you ever sell your home.
What to Look for in a Northshore AC Installer
- A load calculation performed before equipment is recommended
- A written proposal that specifies the equipment, refrigerant type, and everything included in the price
- Licensed, EPA-certified technicians
- Permits pulled for every installation
- A full commissioning process with documented measurements after startup
Each of these points protects your investment. Skipping any of them costs you money and comfort over the life of the system.
Ready to Schedule Your AC Installation on the Northshore?
Southern Air has been serving the Northshore area since 1984. Our installation teams follow a complete process from load calculation to final commissioning, and we handle permits on every job. We offer flexible financing options and upfront pricing with no surprises.
Check our specials page for any current installation promotions, and ask about our Shield of Protection plan to protect your new system from day one.
Call us at (985) 200-5442 or schedule online to get started.
