The August FPL bill is the first thing we read before quoting a St. Augustine air conditioner

What a hot-month bill is pointing at

When the Florida Power & Light bill for a St. Augustine house jumps in July or August, the air conditioner gets the blame, and about a third of the time it deserves it. The other two causes are ductwork losing cold air into a 130-degree attic, and a house envelope that leaks: original single-pane sliders on a 1979 St. Augustine South ranch, a lanai door that stays open, bath fans dumping into the attic.

Only the first of those is fixed by a new unit. A compressor that is seventeen years old and pulling more amps every summer is a real reason to buy; a leaking return plenum is not. So the first thing we do with a buyer is read the bill, look at the kilowatt-hours against last August, and then look at the ducts before anyone talks about tonnage.

Retrofit in a 1926 bungalow, new install in a 2024 build

Those are the two ends of the St. Augustine market, and they get different equipment for different reasons.

In Nelmar Terrace, Fullerwood Park or the Model Land District, the house was built with no ductwork at all. Somebody added it decades later, usually through the attic with whatever fit. A new air conditioner there is a retrofit in the honest sense: the condenser has to go where preservation rules allow, the air handler has to fit a closet that was never meant for one, and the ducts have to be tested rather than trusted. A smaller, variable-speed unit that can run at low capacity for long stretches is usually the right fit, because it tolerates imperfect airflow better than a big single-stage unit does.

In Palencia or on the Nocatee edge, the house was designed around the system. The ducts are sized, the returns exist, and the question is mostly efficiency tier and whether the builder-grade unit is worth keeping until it fails. Here the quote is straightforward and the FPL rebate on a high-efficiency replacement is the main variable.

The duct situations we find in this town

• No original ducts. Colonial Quarter, Lincolnville, Abbott Tract. Retrofit runs or ductless; sometimes both.
• 1950s slab houses in Davis Shores. Ducts in the ceiling or a furred-down hallway, often undersized, sometimes damaged by past flooding.
• 1970s to 1990s block ranches. St. Augustine Shores, St. Augustine South, Marsh Creek. Attic duct, garage or closet air handler, a single return that was marginal when new.
• 2000s flex duct. World Golf Village, Murabella. Adequate when installed, now twenty years old, with sagging runs and loose boots.

The air conditioner we quote depends on which of those you have, and whether the duct fix belongs on the same invoice.

Schedule a load calculation

Sizing: the number on the old unit is not the answer

We measure the house. Square footage, orientation, window area and glass type, insulation, ceiling height, the shade from that oak canopy, and how the house is used. From that comes a cooling load in tons, and in St. Augustine’s humidity the right answer is usually a little smaller than the unit that was there, with longer run times that pull water out of the air. A 32084 bungalow with new windows may need two tons where it has three; a Marsh Creek two-story with a west-facing wall of glass may need every bit of what it has.

Straight-cool or heat pump: the short version

An air conditioner cools and leaves heating to electric strips or a furnace. In this climate the strips run a few mornings a year, so a straight-cool unit is a reasonable buy where the house already has gas heat it likes. Everywhere else, the heat pump version of the same Lennox unit costs little more and heats for a fraction of what strips cost. We quote whichever one the house argues for, and we tell you why.