Central air conditioning replacement in the Hamptons

What's included

A replacement is normally the outdoor condensing unit and the indoor evaporator coil together, matched by the manufacturer; on an older system the air handler or furnace blower goes too. The contractor recovers the old refrigerant, sets the new unit on a level pad (raised on coastal sites), replaces or flushes the line set, installs the coil, pressure-tests and evacuates the system, charges it to specification, and commissions it: airflow, temperature split, static pressure. A real quote names the model numbers, the SEER2 rating, the refrigerant, what happens to the line set and the ductwork, the electrical work, and the warranty on labor as well as parts.

What it costs (2026)

Tier	Installed cost (national)
Standard efficiency, 14.3–16 SEER2	$3,500–7,500
High efficiency, 17–20+ SEER2	$8,000–12,000
Overall range	$3,500–14,000 (brand-name installs from one major manufacturer average $6,958–13,418)
2-ton system	$3,200–6,500

We have not found a clean published breakdown for 3-, 4- and 5-ton systems, which is what most Hamptons houses need, so we do not print one; read the overall range and expect a large house to sit at the top of it. Adders that show up on South Fork quotes: duct sealing ($1,000–2,500 by one estimate; the Aeroseal process $1,500–6,900), new ductwork at $25–55 per linear foot depending on scope ($40–65 by another estimate for a whole house), a smart thermostat installed at $200–500, and an electrical circuit or panel work by a licensed electrician.

Efficiency: what SEER2 means here

Since January 1, 2023 the federal minimum for a split-system air conditioner in the North region (New York included) is 13.4 SEER2. SEER2 uses a tougher test than the old SEER rating, so the numbers read lower for the same hardware: 13.4 SEER2 is roughly the old 14 SEER. Higher tiers cost more up front and pay back in electricity; at Long Island's 27–28¢ per kWh, one of the highest residential rates in the country, the payback on a 17–20 SEER2 system is shorter here than in most of the country, especially in a house that runs the AC all summer.

The refrigerant change

New equipment built since January 1, 2025 uses R-454B or R-32 instead of R-410A. Two practical consequences. First, a new R-454B system needs a technician trained and equipped for the mildly flammable A2L class; every contractor we send you to is. Second, some R-410A units built before 2025 are still in the supply chain: the federal deadline for installing them was removed in a rule effective July 27, 2026, so they may be installed until inventory runs out. New York's own refrigerant rule may keep a state-level deadline; ask which refrigerant the quoted unit uses before you sign, and prefer the current one on a system you expect to keep for 15 years.

Sizing is a calculation, not a guess

New York's residential code requires heating and cooling equipment to be sized with an ACCA Manual J load calculation and selected per Manual S. A contractor who prices "a 4-ton like you have now" has skipped it. Oversized air conditioners short-cycle and never wring the humidity out of a South Fork summer; undersized ones run flat out on the hot weekends. The load calculation accounts for insulation, windows, orientation and shade, which is why a re-insulated 1990s house often needs a smaller unit than it had.

Salt air

Trade guidance for coastal work: within about 3–5 miles of the ocean, specify a condenser coil with a salt-spray (ASTM B117) rating; within a mile, both the condenser and evaporator coils; on oceanfront sites, the most stringent option the manufacturer offers. Set the unit at least 12 inches above grade (higher in flood zones), and rinse the coil with low-pressure water 2–4 times a year. Some manufacturers' coated coils come at no extra cost on the right model, so this is a specification choice, not necessarily an upgrade line.

Where the unit can go

Placement is regulated. In the Town of Southampton, generators and mechanical equipment must sit at least 10 feet from every property line (8 feet in R-10 districts) and be screened from neighbors. The Town of East Hampton's noise code limits residential property-line noise to 65 dBA by day and 50 dBA at night, which rules out some spots for a loud unit next to a neighbor's bedroom. In the villages' historic districts, a condenser on a street-facing elevation may need review; check first.

Timeline

A straightforward like-for-like swap on ductwork in good condition takes about 4–8 hours, one working day in practice. Adding duct repairs, a new line-set run or electrical work adds a day or two. The Village of East Hampton and Village of Southampton restrict construction hours (summer Saturdays are noon–4pm in East Hampton Village, and Sundays are out), which a one-day swap can usually work around.