AC replacementin Seneca, SC

Which kind of system fits your house?

In most Seneca homes it’s a heat pump: heat pumps do most of the heating here, and many rural homes have no gas line. Gas, dual fuel and packaged systems suit particular houses.

System	Where it fits
Heat pump and air handler	All-electric homes, including most lake houses
AC and gas furnace	Homes on Fort Hill natural gas or propane
Central AC only	A furnace that still has years left in it
Dual fuel	A heat pump for most of the winter, gas for the coldest mornings
Packaged unit	No indoor room for equipment; ducts run through a wall or floor
Manufactured home	HUD-rated equipment feeding under-floor ducts

The price table on this page gives 3-ton ranges for each. Our HVAC replacement cost guide breaks them down by size.

How should the contractor size the new system?

With a Manual J load calculation, not by copying the old unit’s size or using a square-foot rule. A Manual J often shows a house needs less capacity than the rule of thumb says.

The common shortcut is one ton per 500–750 square feet. A Manual J, the ACCA method, works from the actual house: insulation, windows, which way it faces, where the ducts run and local weather. That matters here because an oversized system cools the air fast, shuts off, and never runs long enough to pull out moisture. The house reaches the setpoint and still feels clammy.

A new system on leaky or crushed ducts wastes part of what you paid for, so ask for a duct check in the same visit; see duct sealing and repair.

What do SEER2 ratings mean for a new system?

SEER2 measures cooling efficiency. The legal minimum for a split heat pump, or a split AC up to 3.5 tons, is 14.3 SEER2, and each step up costs more to buy and less to run.

The Department of Energy minimums for the Southeast, in force since January 1, 2023:

• Split AC up to 3.5 tons: 14.3 SEER2
• Split AC of 4 to 5 tons: 13.8 SEER2
• Split heat pump: 14.3 SEER2 and 7.5 HSPF2
• Packaged unit: 13.4 SEER2

15.2 SEER2 is Duke Energy’s first rebate tier, not the legal minimum. The tiers on a 3-ton heat pump:

Tier	What it is	3-ton heat pump
Standard	14.3 to 15.2 SEER2, single-stage	$7,500–$12,000
Better	16 to 17 SEER2, two-stage	$8,400–$14,700
Best	18+ SEER2, variable speed	$9,700–$18,600

Two-stage and variable-speed systems run longer at low speed, which pulls more moisture out of July air. The extra cost pays back faster in a house you’ll keep for years and run hard every summer.

What changed with refrigerants in 2025?

New systems made since January 1, 2025 use A2L refrigerants, R-454B or R-32. An EPA rule from May 2026 lets contractors keep installing leftover R-410A split systems until stock runs out.

• Both halves change together. A new A2L outdoor unit can’t be paired with an old R-410A indoor coil, so replacing one half of a split system usually means both. That’s why a quote should list matched indoor and outdoor models.
• Leftover R-410A systems. They are legal to install and to service, but R-410A has roughly doubled in wholesale price since 2024, and every future leak repair will feel that.

What should a good replacement quote include?

The equipment by model number and the work that makes it run right, written down, so two or three quotes can be compared line by line.

• A Manual J load calculation, with the result
• Matched indoor and outdoor model numbers and their combined SEER2 rating
• The permit
• A new refrigerant line set, or the reason the old one can stay
• The thermostat
• Removing the old equipment, recovering its refrigerant and hauling it away
• Who registers the warranty. Parts warranties typically run 10 years if the system is registered within 60 to 90 days, and 5 if not. Get the labor warranty in writing; it varies by contractor.
• The Duke rebate paperwork, if the system qualifies

If a quote comes with financing, read the terms. Deferred-interest promotions charge all the back interest if the balance isn’t paid off in time.

What rebates and credits are left in 2026?

The federal 25C tax credit is gone for systems installed after December 31, 2025, so the main incentive now is a Duke Energy Smart $aver rebate of about $350–$900 for a qualifying heat pump.

A participating contractor has to submit the Duke rebate within 60 days; confirm current amounts on duke-energy.com. Blue Ridge Electric Cooperative members can ask the co-op about its heat pump loan program. The state’s HOMES and HEAR rebates haven’t launched, so don’t wait on them to replace a failed system. Our guide to SC HVAC rebates and tax credits has the details, and the best time of year to replace HVAC covers timing while the old system still runs.

When you’re ready, get a ballpark price for a new system before the contractor’s visit.