Replacing Your AC on the Treasure Coast: A Homeowner's Guide

Salt air corrodes the outdoor unit's coil and cabinet, especially east of US-1 and on the barrier islands. If you're close to the water, ask about coated coils or corrosion-resistant models, and rinse the outdoor unit with fresh water periodically as your contractor recommends.

Humidity matters as much as temperature. A system that's too large cools the house quickly but doesn't run long enough to remove moisture, leaving the air clammy and encouraging mold.

• Age: many coastal systems need replacement sooner than the lifespans quoted for other climates.
• Repeated repairs, especially refrigerant leaks or a failed compressor.
• Rising electric bills without a change in use.
• Uneven cooling or humidity the system used to handle.
• The system uses an older refrigerant that has become expensive to service.

New systems are rated in SEER2. Florida is in the federal Southeast region, where new split-system air conditioners must meet a minimum of 14.3 SEER2 (13.8 SEER2 for larger units of 45,000 BTU/h and up).

Higher-rated and variable-speed systems cost more but run longer at low speed, which is better for humidity control and comfort — often the bigger benefit in Florida.

• A load calculation (Manual J) for your home rather than "same size as the old one."
• Model numbers for the indoor and outdoor units, and the SEER2 rating of the matched system.
• An inspection of the existing ducts, with any sealing or repairs priced separately.
• The permit and final inspection — AC replacements require a permit.
• Warranty terms for parts and labor, and whether registration is needed.

Look for a license starting with CAC (certified air conditioning) or CMC (certified mechanical), or a registered license valid in your county. Get more than one quote, and compare the equipment and scope, not just the bottom line.