What to Expect During AC Installation: Common Questions and Issues
Trusted Family Owned Air Conditioning Contractor, delivering expert HVAC Services for San Antonio.
What’s Covered on This Page
- New AC Installations Follow a Verified Process, Not a Phone Guess
- Correct Sizing Comes From a Load Calculation, Not the Old Unit’s Tonnage
- Ductwork and Electrical Get Checked Before the Job Is Quoted
- Existing Refrigerant Lines Are Flushed Before They’re Reused
- Permits and City Inspection Are a Standard Step, Not an Add-On
New AC Installations Follow a Verified Process, Not a Phone Guess
A lot of homeowners in San Antonio call around just wanting a number. We give one over the phone. It’s based on typical system sizes and common jobs. This gives you a starting point for comparison. But that number isn’t final until a technician has looked at your house. San Antonio homes vary a lot. Older homes near the city center often have smaller duct runs than newer builds on the north side. This changes what equipment fits and how it performs.
Once you decide to move forward, a technician comes out to verify installation details in person. That includes the system type and size you need. They also check your existing ductwork, the line set, your electrical setup, your home’s square footage, and insulation levels. We run a heat load calculation (Manual J) and a CFM calculation for your ductwork before writing the estimate. Skipping this step is how homes end up with a unit that’s too big or too small. We’ve seen this lead to short cycling or rooms that never cool evenly.
After you review and approve the estimate, we collect a 50% deposit. You can also use our 0% financing option. We install the system, collect the remaining balance, or process financing. Then we schedule the city inspection. We also register your new equipment in your name, which protects the manufacturer’s parts warranty. And we start any rebate paperwork you’re eligible for with your utility company.
- Phone pricing based on your system type and home size
- On-site technician visit to verify ductwork, electrical, and insulation
- Manual J heat load and CFM duct calculations before the estimate is written
- Written estimate for you to review before any deposit is collected
- City inspection, equipment registration, and rebate paperwork after installation
If you want to see how this plays out with actual system pricing, our AC Installation page breaks down cost by unit size and type.
Correct Sizing Comes From a Load Calculation, Not the Old Unit’s Tonnage
We don’t size your new AC off the tonnage sticker on your old one. That number might have been wrong the day it went in. Or your home may have changed since then with added insulation, new windows, or a room built out. So when you call about replacing your system, we don’t just swap in the same size.
After you call or chat with us about AC installation, we start with pricing over the phone. This is based on common setups. Then we send a technician to your house to check the details that decide sizing.
- System type and size currently installed
- Ductwork condition and layout
- Line set length and condition
- Electrical setup at the unit and panel
- Square footage of the home
- Insulation levels
Once we have that information, we run a heat load calculation. This is sometimes called a Manual J, along with a CFM calculation for your ductwork. That math tells us how much heat your house gains and loses. It looks at it room by room in some cases, not just square footage on a form. It’s the difference between guessing and knowing what size unit your ducts can move air through.
We’ve walked into plenty of San Antonio houses where the ductwork was sized for a smaller system than what’s currently running. Or the attic insulation clearly got upgraded at some point, but the AC did not. Either one changes what size unit makes sense. A load calculation catches that before we build your quote. Not after we’ve already installed the wrong size.
This walkthrough and calculation happen before we build your estimate. That visit is part of our free estimate. You’re not paying to find out what size your home needs.
If the load calculation says your ductwork can’t support the size that would otherwise fit your square footage, we’ll tell you that directly. Sometimes that means talking about duct changes before an installation date gets set. We’d rather bring that up early than install a system your ducts can’t move air through properly.
You can see how this sizing step fits into the rest of our AC installation process on our main service page.
Ductwork and Electrical Get Checked Before the Job Is Quoted
The number you get on the phone moves once a technician sees your house. Before we lock in a final estimate, we send someone out to check the installation details in person. This step catches things a phone call never will.
On the visit, our technician looks at system type and size, the condition of your ductwork, the line set running to the outdoor unit, your electrical setup, the size of your home, and how well it’s insulated. Older San Antonio homes often have ductwork that was sized for a smaller unit decades ago. Or a line set that’s been patched more than once. Electrical panels in homes built before the 1990s sometimes don’t have the capacity a new system needs without an upgrade. None of this shows up until someone is standing in your attic or garage looking at it directly.
After we gather that information, we run a heat load calculation, also called a Manual J. This also includes a CFM calculation for your ductwork. This tells us the actual size unit your house needs, not just a guess based on square footage. A common mistake homeowners make before calling anyone is assuming a bigger unit is better. It isn’t. An oversized system cools the air fast but shuts off before it pulls enough humidity out. San Antonio summers make that humidity problem worse, not better.
Ductwork gets more attention during an installation than most people expect. Leaky or undersized ducts can make a brand new, correctly sized AC unit perform like it’s the wrong size. We check for this because installing a new system on top of bad ductwork just moves the problem instead of solving it.
Once we’ve gathered all the site information and run the calculations, we build a written estimate for you to review. There’s no pressure to sign on the spot. If the numbers change from what was quoted over the phone, we explain exactly why. Whether it’s ductwork modifications, an electrical upgrade, or a different tonnage than originally assumed.
This on-site check is part of our free estimate process. So there’s no cost to find out what your home needs before you commit to anything.
Ready when you are – get in touch today.
Get a Free Estimate. Atlas AC Repair is ready to help.
Existing Refrigerant Lines Are Flushed Before They’re Reused
Most AC installation jobs in San Antonio don’t replace the copper line set. This is the part running between the outdoor unit and the indoor coil. The lines usually sit inside walls or attic space. Pulling them out means cutting drywall or insulation for no real gain. So we reuse them. But we don’t just hook the new unit up to old copper and call it done.
Before we reconnect anything, we acid-flush the existing line set. This pushes a cleaning solution through the copper. It pulls out old refrigerant oil, metal shavings, and moisture that built up over the life of the previous system. On older homes, we’ve opened up lines that had visible rust flakes and sludge sitting near the joints. This is especially true on systems that ran past 12 or 15 years without much upkeep. That residue doesn’t belong in a new compressor.
Skipping this step is one of the more common corners cut on installation jobs. Debris left in the lines can travel into the new outdoor unit. This shortens the life of the compressor fast, sometimes within the first year or two. It’s not a visible problem on install day. It shows up later as a warranty claim or a no-cool call nobody expected.
After the flush, we install a new drier filter in the line set. The filter traps any leftover moisture or particles the flush didn’t catch. This protects the refrigerant charge going forward. We also install locking caps on the freon valves once the system is charged and running. That’s a small detail, but it keeps the valves from being opened or tampered with after we leave the property.
Once the lines are flushed, the filter is in, and the system is commissioned and calibrated to the manufacturer’s specs, we walk the homeowner through what was done. This is part of how every installation gets set up under our AC Installation process. This applies whether the job is a straight AC replacement or a full furnace and coil swap.
If you’re comparing quotes for a new system, it’s worth asking whether the line set gets flushed or just reconnected. It’s a step that’s easy to skip and hard to verify later. This is part of why we bring it up before anyone signs off on the work.
Permits and City Inspection Are a Standard Step, Not an Add-On
A city permit and inspection come with every new AC installation we do. This isn’t something we charge extra for or something you have to ask about. It’s part of the job from the start.
Here’s what that looks like in practice. Once the installation is done, we pull the required city permit and schedule the inspection. An inspector checks things like the disconnect labeling near the outdoor unit, the drain pan setup, and electrical clearances around the equipment. These are the same details our own techs check before we ever call for inspection, so most jobs pass without a second visit.
We also register the new equipment in your name after the install. This step protects your 10-year manufacturer parts warranty. If equipment isn’t registered, some manufacturers will only honor a shorter default warranty period instead of the full one.
We start the paperwork for any local utility rebates you may qualify for. Then we hand that off for you to finish and submit. Rebate programs and their requirements change, so we can’t promise a dollar figure. What we can do is get that paperwork moving so you’re not starting from zero.
One thing worth knowing: permitting and inspection scheduling add time to a project. The city has to be available to inspect, and that’s outside our control. If a contractor tells you a job can skip this step entirely to save time, that’s worth asking more about. Skipping it can leave you without proof the work meets code. This matters if you sell the home later or file an insurance claim.
- City permit pulled before or at install, depending on the job
- City inspection scheduled after installation is complete
- Equipment registered in the homeowner’s name to protect the parts warranty
- Rebate paperwork started for the homeowner to review and submit
If you want to see how this fits into the full job from first call to final walkthrough, our AC installation process page lays out each step in order.
