Ductwork — Florida's hidden 30% problem.

Almost always, yes. A new condenser and air handler cool conditioned air just fine. The problem is that conditioned air has to travel through your duct system to reach the rooms — and if those ducts are leaky, they're pulling humid 140°F attic air into the return side. That warm, wet air dilutes the supply air before it even reaches the registers. You paid for 20 SEER2 equipment; you're getting roughly 14 SEER2 performance because of the duct losses. This is the single most common reason homeowners are dissatisfied with a brand-new system.

It depends on what the ducts are made of. Flexible duct (the insulated plastic tubing used in most Florida homes built after 1990) has a typical service life of 15–20 years — the insulation degrades from UV exposure in the attic and the inner liner gets brittle. Fiberglass duct board (common in 1970s–80s homes) typically fails at 25–30 years; the fiberglass starts shedding and the joints open. Galvanized sheet metal (pre-1970s commercial-style ducts in some older Florida homes) can last 50+ years if the joints were sealed properly, but most weren't, so the leak rate is the problem rather than structural failure.

Industry consensus is that the average Florida duct system leaks 20–30% of conditioned air before it reaches the registers. On a 3-ton system running 8 hours a day in July, that's roughly 180 kWh per month of cooling that never cooled anything — roughly $25–$35 on your bill depending on your utility. Over a 12-month cycle in Florida's climate, that's $250–$400 a year in wasted electricity, plus accelerated compressor wear from the system running longer to maintain setpoint. Add in higher dehumidification load and comfort complaints, and the case for duct remediation is usually paid back in 2–3 years.

Not always — but you need to inspect them, and in Florida the answer is more often yes than in most other climates. The rule of thumb: if your ducts are under 10 years old, in good visual condition, and tested tight, keep them. If they're 15+ years old, have visible insulation damage, have been patched with duct tape (which fails in 2–3 years in attic heat), or have never been mastic-sealed at the joints, replace them. A system replacement is the only practical window to replace ducts because the work requires hours of attic access that's cost-prohibitive as a standalone project.

A duct blaster is a calibrated fan that pressurizes the duct system to 25 pascals while the tester seals the supply registers. The measured airflow required to maintain that pressure is your total duct leakage, reported in CFM25. A tight residential duct system should leak less than 6 CFM per 100 sq ft of conditioned floor area. Typical Florida homes test at 15–25 CFM — two to four times the target. We include a duct blaster test on every Premier and Optimum install and provide the before/after numbers in writing so you can see exactly what you bought.

Usually not mold — more commonly, it's dust that's been pulled from insulation through return-side duct leaks. If the dust is grayish and concentrated around specific registers, that's the tell: something nearby is leaking return-side and pulling attic insulation fibers into the system. Actual mold in ducts looks different: patchy, often greenish-black or white fuzzy colonies, and concentrated at damp spots (near the evaporator coil, at condensate drip points). Mold in ducts is a legitimate health concern that warrants remediation by a licensed mold assessor, not a standard HVAC technician.

R-value measures thermal resistance — how well the duct insulation keeps attic heat from warming up conditioned supply air. Florida building code requires R-6 minimum for supply ducts in unconditioned attics; R-8 is recommended. Duct installed before 2005 often has R-4 or R-4.2, which is inadequate for Florida attic conditions (140°F+ in summer). Upgrading from R-4 to R-8 reduces the duct-thermal-loss component of your cooling load by roughly 40%. On a system replacement, specifying R-8 ducts is a $200–$400 upcharge that pays back faster than any other component spec.

Yes — and it's the single biggest efficiency handicap of Florida residential HVAC design. An attic in Miami hits 140°F for 4+ hours a day in July. Your supply air is leaving the air handler at 55°F and has to travel through 20–40 feet of duct in that oven before reaching a register. Even with R-8 insulation, you lose 2–4°F of supply temperature to the attic environment, and every leak magnifies the effect. The building-science ideal would be ducts inside conditioned space (dropped ceilings, interior chases). Retrofitting that is impractical, so the realistic remediation is better sealing, better insulation, and shorter runs.

No. The material called 'duct tape' is one of the few things in residential construction that should never be used on an actual duct — the adhesive fails under attic temperature cycling within 18–24 months. Proper duct sealing uses either water-based mastic (brushed onto joints and reinforced with fiberglass mesh) or aerosol-applied sealant that's blown through the ducts under pressure (Aeroseal). Mastic is the contractor standard and lasts the life of the duct. Aeroseal is a specialized service that seals leaks from the inside and is typically $1,500–$3,000 for a whole-house treatment — worth it when the ducts are otherwise in good condition.

Yes — we offer a $149 duct inspection + duct blaster test that is fully credited back if you move forward with a system replacement within 90 days. The inspection includes a photo walk-through of all accessible ducts, joint-by-joint condition notes, insulation R-value readings, and the duct blaster CFM25 result. You get a written report you can use to compare contractor quotes or just to understand your system — we don't require a replacement quote to run the test.