Short answer: A standard residential AC installation in Las Vegas takes 6 to 10 hours. Your crew arrives between 7 and 8 AM, removes the old system, prepares the site, installs new indoor and outdoor units, runs new refrigerant lines, charges the system, tests every measurement, and walks you through the finished job by late afternoon. You will be without cooling during the work. This guide walks you through every hour so nothing surprises you.
Ready to schedule? Call (702) 567-0707 or get a quote online.
Key Takeaways
- Installation day follows a predictable sequence. Old system removal, site preparation, new equipment installation, testing, and final walkthrough. Knowing the sequence eliminates the anxiety of wondering what is happening and why.
- Preparation the day before makes everything smoother. Clearing paths, securing pets, planning for no AC, and moving breakables prevent delays and protect your home.
- The "prep" phase separates quality companies from the rest. New copper line sets, proper condenser pad leveling, upgraded electrical, and nitrogen pressure testing determine whether your system lasts 8 years or 20.
- Testing is not optional — it is proof of quality. Temperature split, superheat, subcooling, and static pressure are measurable numbers that confirm your installation was done right. Ask for them.
- Red flags are identifiable in real time. A rushed job, reused line sets, skipped pressure tests, or evasive answers about warranty registration are signals you can spot and should speak up about immediately.
Why Knowing What to Expect Matters
You signed the contract. You chose the equipment. You scheduled the date. And now you are lying awake the night before wondering what tomorrow actually looks like.
A new AC system is an $8,000 to $15,000 decision — one of the largest purchases you will make for your home. Maybe you read our guide on 17 questions to ask before buying. Maybe you timed your purchase for the spring buying window. You have made every right move so far. But nobody told you what actually happens on the day.
I have overseen thousands of installations across the Las Vegas valley. I have watched homeowners hover nervously while my crew works — not because anything is wrong, but because they do not know what is normal. I have seen people panic over routine sounds and stay too polite to ask questions they should be asking.
This is the walkthrough I wish every homeowner had. Hour by hour, from the moment our truck pulls into your driveway until we hand you the keys to your new system.
Your Installation Day Timeline at a Glance
| Time | Phase | What Is Happening | Duration |
|---|---|---|---|
| 7:00–8:00 AM | Crew Arrival | Introductions, walkthrough, floor protection, equipment staging | 30–60 min |
| 8:00–10:00 AM | Old System Removal | Refrigerant recovery, disconnect electrical, remove indoor and outdoor units | 1.5–2 hrs |
| 10:00–11:30 AM | Site Preparation | New line set, condenser pad, electrical upgrades, drain line | 1–1.5 hrs |
| 11:30 AM–3:00 PM | New System Install | Indoor unit, outdoor unit, thermostat, refrigerant lines, electrical | 3–4 hrs |
| 3:00–4:30 PM | Testing | Vacuum, charge, startup, performance measurements | 1–1.5 hrs |
| 4:30–5:00 PM | Walkthrough | System orientation, thermostat training, paperwork, warranty | 20–30 min |
Total elapsed time: roughly 8 to 10 hours for a standard replacement. Simpler changeouts can finish in 6. Installations involving significant ductwork modification or system relocation may extend to a second day.
Before Installation Day: How to Prepare Your Home
The Week Before
Clear a path to the indoor unit. Your air handler or furnace lives in a utility closet, garage, or attic. Move storage boxes, holiday decorations, and anything blocking access. Do this now — not at 7:15 AM with three installers waiting.
Clear the outdoor unit area. The condenser needs at least six feet of clearance for the crew to work. Move patio furniture, planters, and garden hoses.
Move vehicles out of the driveway. Our trucks carry the new equipment, tools, copper line sets, and materials. A clear driveway saves time and protects your car.
Trim vegetation around the condenser area. The new unit needs 24 inches of clearance on all sides and 60 inches above for proper airflow.
Note your thermostat preferences. What temperature do you keep? Do you use a schedule? Do certain rooms run hot? Telling the crew during the walkthrough helps them set up the new system to match your habits.
The Night Before
Remove breakables from walls near the indoor unit. HVAC work involves drilling and hammering. Vibration travels through studs and drywall. That framed photo near the utility closet? Take it down.
Secure pets. Doors will be open for hours, strangers will be walking through, and power tools will be running. Board pets, confine them to a room away from the work, or arrange for someone to take them. I have seen installations delayed 45 minutes because a Labrador decided the open front door was an invitation to tour the neighborhood.
Plan for no AC. Your old system shuts down in the morning. The new one does not come online until late afternoon — a 6-to-8-hour gap. In summer, that means a house approaching 95 degrees. Go somewhere cool for the afternoon, set up fans, have cold water ready. The customers who plan ahead have a much better day than those who try to tough it out.
Plan for your family. Kids: arrange a playdate or outing — installation is a construction zone. Work from home: expect heavy noise, bring headphones or work elsewhere. Elderly family members: no AC for hours can be a health concern in summer — consider having them spend the day at a cooler location.
Crew Arrival and Initial Setup (7:00–8:00 AM)
The first thing you will notice is the truck. It carries your new outdoor unit, indoor unit, copper line sets, PVC drain components, electrical supplies, sheet metal, brazing equipment, vacuum pumps, refrigerant gauges, and enough hand tools to fill a workshop.
Las Vegas crews start early. Arriving between 7 and 8 AM means the hardest outdoor work — lifting the condenser, brazing copper lines — happens in the coolest part of the day. By afternoon, the heavy outdoor work is done. There is a reason you will never see an experienced Las Vegas HVAC crew scheduling a condenser swap for 2 PM in July.
A standard residential replacement requires two to three technicians: a lead installer who is responsible for every critical decision and the final signoff, and one or two assistants. Every person entering your home should be in uniform, carrying identification, and willing to introduce themselves by name. If someone shows up in street clothes with no ID, ask questions. You have every right to know who will be working in your house for the next 8 hours.
The Initial Walkthrough
Before any tools come off the truck, the lead installer walks the job with you. This walkthrough serves three purposes.
Verify the scope. The lead confirms what equipment is being installed, where it goes, and what modifications were agreed upon during the quote phase. This is your last chance to clarify before work begins. "Are we also installing the new thermostat?" "Is the condenser going in the same spot?" "Did we decide to add the surge protector?" Confirm everything now.
Inspect access and conditions. The installer checks that paths are clear, identifies where protective coverings need to go, and notes anything fragile or valuable near the work areas.
Set expectations. A good lead tells you the approximate timeline, when you will lose AC, when the noisiest work happens, and when they will need you available. They will ask where to park, where to stage equipment, and whether there is anything else they should know about the house.
Then the crew lays protective coverings along every path between the truck and work areas. Drop cloths on floors. Padding on wall corners and door frames along tight paths. Your home is not a construction site, and installers who skip floor protection are telling you something about how they treat customers' property.
The new equipment comes off the truck and is staged on the driveway or in the garage. The outdoor condenser is larger than most people expect. The air handler comes in a box. There will be a coil of copper tubing, boxes of fittings, insulation, PVC pipe for the drain, and electrical supplies. It looks like a lot. It is.
Old System Removal (8:00–10:00 AM)
Refrigerant Recovery
The first step is recovering refrigerant from the old system. This is not a preference — it is federal law. Under EPA Section 608, venting refrigerant into the atmosphere is illegal, with fines up to $44,539 per day per violation. Every ounce must be captured using a recovery machine and stored in a certified tank for proper reclamation or disposal.
This takes 15 to 30 minutes depending on system size and refrigerant volume. You will hear the recovery machine running — it sounds like a small air compressor. The technician monitors the process with gauges until system pressure reaches the required vacuum level, confirming all refrigerant has been captured. A company that skips proper recovery to save 20 minutes is telling you everything about how they cut corners on the rest of the job.
Outdoor Unit Removal
Electrical is disconnected. Refrigerant lines are cut. The unit — 150 to 250 pounds — is unbolted and lifted off the pad. The crew inspects the concrete pad: is it level, cracked, or sinking? In Las Vegas, caliche soil can heave around irrigated landscaping. A tilted pad creates vibration and stresses the compressor.
Indoor Unit Removal
The air handler or furnace is disconnected from ductwork, electrical, the drain line, and gas (if applicable). This is careful work — the existing ductwork connections need to remain intact for the new unit. Attic installations require maneuvering a 100-plus-pound unit through an access hatch and down a ladder, which is why you want experienced installers who have done it hundreds of times.
What Happens to the Old Equipment?
The metals — copper, aluminum, steel — are recycled. Refrigerant goes to a certified reclamation facility. Removal and disposal should be standard, not an add-on. If it is listed as extra on a full system replacement, ask why.
Site Preparation and Upgrades (10:00–11:30 AM)
This is the phase most homeowners do not know about. It is also the phase that separates a mediocre installation from one that lasts two decades.
New Copper Refrigerant Line Set
A quality installation uses new copper refrigerant lines. Always. The line set — the pair of copper tubes connecting the indoor evaporator coil and outdoor condenser — should be replaced with every system.
Old lines may contain contamination from a previous compressor failure, microscopic debris, or degraded insulation. Reusing them saves the installer $150 to $300 in materials and saves you nothing. A contaminated or undersized line set can cause premature compressor failure — a $2,000 to $4,000 repair on a system you just paid thousands for.
New lines are cut to length, bent smoothly (kinks restrict refrigerant flow), insulated with closed-cell foam, and routed cleanly along the exterior wall or through the attic.
Electrical and Drain Work
Your new system may need a new disconnect box, a breaker upgrade, or new thermostat wiring for smart or communicating thermostats. A new PVC condensate drain line is installed with proper slope for gravity drainage. A clogged or improperly sloped drain causes water damage — ruined drywall, mold, and potentially tens of thousands in remediation.
Common Add-Ons
These should have been discussed during the quote phase, not sprung on you during installation:
- Condensate drain safety switch — shuts off the AC if the drain clogs. $30 to $50 in parts. Prevents thousands in water damage.
- Surge protector for the outdoor unit — $75 to $150. Protects a $5,000-plus piece of equipment from lightning and power fluctuations during monsoon season.
- UV light in the ductwork — kills mold and bacteria as air passes through. Optional but increasingly popular.
If an installer suggests anything not in the original quote, they should explain what it is, why, and what it costs — before installing it.
New System Installation (11:30 AM–3:00 PM)
This is the main event. Everything before was preparation.
Indoor Unit
The new air handler or furnace goes into its designated location — garage closet, utility room, or attic. The unit is positioned, leveled, and secured. Then the connections begin.
Ductwork connection. The indoor unit connects to supply and return ductwork through sheet metal transitions called plenums. If the new unit differs in size or configuration from the old one — which is common — the crew fabricates new transitions on site. This is where you hear sheet metal being cut and bent. The transitions are sealed with mastic or UL-listed foil tape (never cloth duct tape, which degrades in heat) to prevent air leaks.
Electrical connection. The unit is wired to its dedicated circuit. All connections are properly sized, terminated, and secured.
Drain line connection. The new drain pan and PVC drain line are connected and tested. The crew pours water into the pan to verify it flows freely and exits at the drainage point. A drain test now prevents a 2 AM water emergency three months from now.
Gas line reconnection. If your system includes a gas furnace, the gas supply is reconnected and leak-tested with an electronic gas detector or soap bubbles. Gas connections are not something any installer takes lightly. A leak is a safety hazard. Period.
Outdoor Unit
The condenser is placed on the prepared pad, leveled, and secured. Then the critical connections:
Refrigerant lines are brazed — permanently joined using a high-temperature torch and silver-bearing alloy. Brazing creates joints stronger than the copper itself. This is different from flared (compression) fittings. If your installer uses flare fittings on permanent line set connections, ask why.
Nitrogen pressure test. Before any refrigerant enters the system, the crew pressurizes the lines to 300-400 PSI with dry nitrogen and watches the gauge for 15 to 30 minutes. Any pressure drop means a leak — a bad joint, a cracked fitting, a manufacturing defect. Finding it now is infinitely easier than chasing a slow leak after the system is running. This test is non-negotiable. If you never see a nitrogen tank at your job site, ask about it.
Electrical and communication wiring connects the indoor and outdoor units. Modern variable-speed systems rely heavily on this link — a loose connection causes intermittent faults that are maddeningly difficult to diagnose later.
Thermostat
The new thermostat is mounted, wired, and — if it is a smart thermostat — connected to Wi-Fi with the app set up on your phone. For optimizing your settings, read our thermostat programming guide.
What Quality Looks Like
You do not need to be an HVAC technician to spot these signs of a quality job:
- All refrigerant connections brazed, not flared
- Nitrogen pressure test completed
- Refrigerant lines fully insulated — no exposed copper
- Clean, organized wiring — not a tangled mess
- Level condenser unit (check with a bubble level)
- Sealed ductwork connections with mastic or foil tape
- Clean work area throughout
This is where 20-year reliability is built. Not in the brand name on the box. In how much the crew cares about doing it right.
Testing and Commissioning (3:00–4:30 PM)
Vacuum and Charge
A vacuum pump removes all air and moisture from the refrigerant lines — moisture creates acid that corrodes components from the inside. The crew monitors with a micron gauge, targeting below 500 microns. Once the vacuum holds stable for 10 to 15 minutes, the system is tight and dry.
Then refrigerant is released from the condenser's factory pre-charge, with additional refrigerant added to match the line set length. Too much floods the compressor. Too little starves the evaporator. The correct charge is verified by measuring superheat and subcooling.
Performance Testing
The system runs for 15 to 20 minutes to stabilize, then the crew measures what matters:
Temperature split — the difference between return and supply air temperature. Should be 15 to 20 degrees. You can verify this yourself with a $10 thermometer. If you have been following our AC stress test checklist, you already know this measurement.
Static pressure — resistance to airflow in your ductwork. Like blood pressure for your AC. Too high means the blower works too hard. This is a key part of any ductwork assessment.
Airflow at every register — every room should have adequate airflow. If a problem room persists with the new system, the issue is ductwork, and now is the time to identify it.
What the Numbers Should Look Like
Ask for these measurements. Write them down. Keep them with your warranty paperwork.
| Measurement | What It Tells You | Acceptable Range | Red Flag |
|---|---|---|---|
| Temperature Split | Cooling performance | 15–20°F | Below 12°F or above 22°F |
| Superheat | Refrigerant charge (fixed-orifice) | 10–15°F | Below 5°F or above 20°F |
| Subcooling | Refrigerant charge (TXV systems) | 8–12°F | Below 5°F or above 18°F |
| Static Pressure | Ductwork airflow resistance | 0.50" WC or less | Above 0.70" WC |
| Compressor Amps | Electrical load | Within data plate RLA | Exceeding RLA by 10%+ |
A contractor who measures, records, and shares these values stands behind their work. A contractor who says "it's blowing cold, you're good" without instruments is a contractor you should question.
The Walkthrough and Handoff (4:30–5:00 PM)
The equipment is installed and tested. The numbers look right. Now the lead installer shifts from technician to teacher. This phase is about you — making sure you understand your new system and feel confident with it.
Where the filter is and how to change it. This sounds basic, but filter location varies by system and installation type. Some are at the return grille. Some are at the air handler. Some have multiple locations. Your installer shows you exactly where, what size, and how often to change it. For a new installation: change it after 30 days — construction dust enters the ductwork, and that first filter catches the worst of it.
Where the electrical disconnect is. The outdoor switch that kills power to the condenser. You need to know its location for emergencies or before a service technician arrives.
Where the condensate drain terminates. So you can periodically verify water is flowing and the line is not clogged.
How to reset the system. Most modern systems have a reset procedure — typically turning off the thermostat, waiting a few minutes, and turning it back on. Knowing this saves you a service call at 11 PM over a simple reset.
What sounds are normal. A new system sounds different from the old one. Different compressor tone. Different fan speeds if you have a variable-speed system. A slight refrigerant whoosh on startup. Your installer tells you what to expect so you do not panic when you hear an unfamiliar sound the first night.
What is NOT normal. Grinding, screeching, banging, hissing, or water dripping where it should not be. If you hear or see any of these, call immediately.
If you have a smart thermostat, the installer walks you through programming a schedule, setting up the app, understanding hold vs. schedule modes, and what the different fan settings mean. For a deeper dive, our thermostat programming guide covers Las Vegas-specific optimization.
Paperwork You Should Have
Manufacturer warranty registration — your installer should register on your behalf. Many manufacturers default to 5-year coverage if not registered within 60-90 days; registration extends it to 10 years. Get the confirmation number.
Installer labor warranty — separate from the manufacturer warranty. Covers labor if a component fails due to an installation defect.
Permit card — posted at the job site. A city inspection follows within one to two weeks.
Commissioning measurements — the performance numbers from testing. These are the baseline readings for your system's health. Every future service visit can reference them.
Equipment manuals — for the air handler, condenser, and thermostat. Keep them with the rest of your paperwork. You probably will not read them cover to cover, but they matter when a technician asks a question about your system five years from now.
This is your time. The crew is finished. The system is running. Ask every question you can think of. What does this button do? What is that sound? How often should I call for maintenance? A good installer welcomes your curiosity — they know informed homeowners take better care of their systems, call for maintenance instead of ignoring problems, and recommend them to their neighbors.
After Installation Day
The City Inspection
If your installer pulled a permit — and they should have — a city inspector will visit to verify code compliance. In Clark County, this inspection is typically scheduled within one to two weeks after installation. Your HVAC company coordinates the scheduling. You may or may not need to be home, depending on whether the inspector needs interior access.
The inspector checks electrical connections (proper wire sizing, secure terminations, correct breaker), refrigerant line installation (support, insulation, routing), gas connections if applicable (leak test, proper materials, shutoff valve), and clearances (minimum distances from walls and property lines). With a quality installation, this is a formality. If issues are found, the HVAC company is responsible for correcting them — not you. The inspection exists to protect you, which is one more reason permits matter.
The First Week
The system may cycle more frequently as it stabilizes. Smart thermostats take one to two weeks to learn your schedule. Monitor the temperature split a few times — it should stay in the 15-to-20-degree range. Note any unusual sounds and call your installer if anything seems off. It is always better to ask a "silly" question than to let a real problem grow.
The First Month
Change the filter at 30 days. You will be surprised how dirty it is from construction dust.
Verify energy bills are trending lower. Savings are most dramatic during summer when the AC runs heaviest.
Confirm warranty registration. Follow up if you have not received confirmation. A registered 10-year warranty versus an unregistered 5-year warranty is a $2,000-plus difference in coverage.
Schedule maintenance. Our Comfort Club provides twice-yearly tune-ups that maintain peak performance and warranty compliance. First tune-up is typically at six months.
Red Flags: When to Speak Up
You are the customer. This is your home and your money. If something looks wrong, ask about it.
The job finishes in under four hours. A full replacement cannot be done properly that fast. Ask what steps were completed.
No nitrogen pressure test. If you never saw a nitrogen tank, the lines were not tested for leaks before charging.
Reusing the old line set. New copper should be standard. If the crew did not run new lines, ask why.
No vacuum pump. Skipping the vacuum introduces moisture and air that shorten compressor life.
No performance measurements. If the crew does not measure temperature split, static pressure, and charge verification after startup, they are not confirming the installation is correct.
Leaving a mess. Scrap copper, packaging, metal shavings, and dirty handprints are not acceptable. A crew that does not respect your home during the job did not respect it inside the walls either.
Evasive about warranty registration. "We'll handle it later" should prompt a follow-up. Unregistered warranties are a ticking time bomb.
Speaking up is not confrontational. If you have asked the right questions before buying, you know what quality looks like. Hold your installer to that standard.
Frequently Asked Questions
How long does it take to install a new AC system?
A standard residential split system replacement takes 6 to 10 hours — including removal, preparation, installation, testing, and walkthrough. Simpler changeouts finish in 5 to 6 hours. Complex jobs involving attic relocations or significant ductwork can extend into a second day. A full replacement that finishes in under four hours should raise questions about skipped steps.
Do I need to be home during AC installation?
Someone should be present for the initial walkthrough (to verify scope and answer questions) and the final walkthrough (system orientation, paperwork, thermostat training). During the middle of the day, you can leave. Just make sure the crew has your cell number.
Will I be without AC during the installation?
Yes. The old system is removed in the morning and the new one comes online in late afternoon — typically a 6-to-8-hour gap. In spring or fall, that is manageable. In a Las Vegas summer, plan ahead: spend the afternoon somewhere cool, set up fans, and keep cold water available.
How do I know if the installation was done correctly?
Ask for the commissioning measurements: temperature split (15–20°F), superheat or subcooling (confirming proper charge), and static pressure (confirming airflow). Look for brazed connections, insulated line sets, clean wiring, a level condenser, and sealed ductwork joints. If the crew skipped the nitrogen test or vacuum, those are serious concerns.
What should I do if I have problems after installation?
Call your installer first. Common first-week concerns — thermostat questions, unfamiliar sounds, rooms that seem warm — are usually resolved with a quick adjustment. Genuine malfunctions (system will not start, blowing warm air, water leaking) should be reported immediately. Post-installation issues are almost always covered under the installer's labor warranty.
Should the installer pull a permit?
Absolutely. Clark County requires a mechanical permit for HVAC installations. The permit triggers a city inspection that verifies code compliance. Without a permit, nobody checks the work — and an unpermitted installation can void your manufacturer warranty and create problems at resale. The fee is $100 to $250 and should be included in your quote.
How loud will the installation be?
Expect construction-level noise during several phases: sheet metal cutting, drilling through walls, and positioning equipment. The noise is intermittent, not constant. If you work from home, plan for noise-canceling headphones or work elsewhere. Most homeowners find it manageable when they are expecting it.
When should I change the filter after a new AC installation?
Change it at 30 days. Even a clean installation sends construction dust into the ductwork. After that initial change, check monthly during Las Vegas summer (June through September) and change every 60 to 90 days otherwise. A clogged filter restricts airflow, reduces efficiency, and stresses the blower motor.
Your New System Starts With a Phone Call
You now know what happens on installation day — from the truck in your driveway at 7 AM to the final walkthrough at 5 PM. What to prepare, what to look for, what to ask, and what numbers prove the job was done right.
Installation day is one day. But the decisions made on that day affect the next 15 to 20 years of your comfort, your energy bills, and your home's value. A properly installed system — with new line sets, tested connections, verified charge, and documented performance — delivers its rated efficiency for its full lifespan. An improperly installed system, even with the exact same equipment, can lose 20 to 30% of its efficiency from day one and fail years early.
If you are planning a new AC installation or replacing an aging system, consider reading our complete home comfort upgrade guide to understand how your new AC fits into your home's overall comfort system. Ductwork, insulation, and thermostat programming all affect how well that new system performs — and addressing them together produces dramatically better results than replacing the AC in isolation.
At The Cooling Company, every installation follows the process described in this article. Every one. Our crews start with protective coverings and a walkthrough, and they do not leave until the numbers are verified and you are comfortable with your new system. That is not aspirational. That is operational.
Call (702) 567-0707 to schedule your in-home assessment, or book online. We will walk you through the options, give you a written quote with no hidden costs, and — when installation day comes — make it exactly as smooth as this guide described.