Key Takeaways
- A standard central AC replacement on Long Island takes 6–10 hours; new ductwork or zoning adds 1–2 days
- Crews typically arrive 7:30–8:30 AM and finish by 4–5 PM the same day for straightforward swap-outs
- Expect 2–3 technicians: a lead installer, an apprentice, and often an electrician for disconnect/breaker work
- Required paperwork at completion: AHRI certificate, equipment registration, and signed commissioning report with subcooling/superheat values
- You should be home at start (walk-through) and finish (system demo), but can leave during the middle of the day
01The Week Before Installation
A few days before install, your project coordinator should confirm:
- Exact equipment being installed (model numbers and AHRI match)
- Arrival window and expected duration
- Any prep on your side (clear basement path, move cars from driveway, secure pets)
- Payment terms and PSEG-LI rebate paperwork (if applicable)
The day before, clear a 3-foot path from the driveway to the indoor unit location and from the outdoor unit location to the electrical panel. Move anything fragile within 6 feet of work areas. Plan for the AC and electricity to your air handler to be off for most of the day — fine for spring/fall installs, plan a hotel or family visit for July/August replacements.
02Hour-by-Hour: A Typical Long Island AC Replacement
7:30–8:30 AM — Arrival and Walk-Through
The lead installer walks the job with you: confirms equipment, reviews electrical disconnect location, identifies any obstacles, and answers last-minute questions. Drop cloths and floor protection go down before any tools come in. You'll be asked to sign a job start authorization.
8:30–10:00 AM — Removal of Old Equipment
The old outdoor condenser is disconnected (electrical, refrigerant lines, drain). Refrigerant is recovered using EPA-compliant equipment — never vented. The old indoor coil and air handler (if being replaced) come out next. Old equipment is loaded for recycling.
10:00 AM–1:00 PM — New Equipment Set
New condenser pad is set (level, properly drained), new line set is run if needed, new indoor coil and air handler are placed and connected to existing ductwork. Refrigerant lines are brazed, pressure-tested with nitrogen, and evacuated with a vacuum pump to remove moisture and non-condensables.
1:00–2:30 PM — Electrical and Controls
Electrical disconnect, whip, and any breaker upgrades are completed. Thermostat is installed and wired. R-454B leak detection sensor (required on new A2L systems) is mounted and tested. Condensate drain with safety switch is installed.
2:30–4:00 PM — Commissioning and Testing
System is charged with refrigerant per manufacturer subcooling spec, started, and run for 15–20 minutes to stabilize. The installer measures and documents:
- Superheat and subcooling values
- Indoor wet-bulb and dry-bulb temperatures
- Outdoor ambient temperature
- Static pressure across the coil
- Temperature split (supply vs. return)
- Amp draw at the compressor
4:00–5:00 PM — Walk-Through and Paperwork
The installer demos the thermostat, shows you the leak sensor and how it behaves, points out the filter location and recommended change interval, and walks through what to expect over the first 24 hours. You receive a commissioning report, AHRI certificate, equipment registration confirmation, and warranty documentation.
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03When Installation Takes Longer
Some projects can't finish in one day:
- New ductwork or duct redesign: Add 1–2 days
- Electrical panel upgrade: Add 4–8 hours (often a separate day with utility coordination)
- Heat pump conversion with new line set routing: Add 4–6 hours
- Adding zoning dampers: Add 1 day
- Inaccessible attic or crawl space: Add 2–4 hours
Multi-day projects always end the workday with the existing or temporary system functional. You won't be without cooling overnight in summer unless we've explicitly coordinated that with you in advance.
04After Installation: What Happens Next
Within 1–2 weeks, the Nassau or Suffolk building inspector will visit to verify the installation passes code. We schedule this and meet the inspector — you don't need to take time off work.
Within 30 days, your equipment registration is filed with the manufacturer to activate the 10-year parts warranty. If you're a PSEG-LI rebate applicant, the program requires the paperwork to be filed through a Participating Partner; eligibility and timing are confirmed in writing before install, and PSEG issues the rebate check 6–12 weeks after the work is completed.
Your first annual tune-up should be scheduled 10–12 months from install date. If you joined Home+ Comfort or Infinite at install, this is already on the calendar.
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05Ready to Schedule Your Install?
Home+ Air and Heat installs central AC, heat pumps, and ductless systems across Nassau and Suffolk counties. Every install includes PSEG-LI rebate processing, commissioning documentation, and a written labor warranty.