Hurricane Season HVAC Prep in Florida

Before the storm: cool deep, then shut down

Once a watch is issued, run the system harder than usual — set the thermostat a few degrees cooler than normal so the house and its contents start the outage as cold as possible. A closed-up Florida house holds that stored cooling for a surprisingly long time. Then, before conditions deteriorate, shut the system down deliberately: off at the thermostat first, then off at the outdoor disconnect or the breaker panel. The reason is electrical. Hurricanes bring exactly the grid behavior that kills HVAC components — repeated brownouts, surges as lines fail and reclose, and voltage sag as the grid strains. A compressor that tries to restart into a brownout can stall under load and overheat; a control board hit by a surge is done regardless of what the rest of the unit looks like. A system that is electrically disconnected cannot be hurt by any of it.

Protect the outdoor unit — but never wrap it while it runs

Flying debris is the mechanical threat. If you have time, clear the yard around the condenser: patio furniture, potted plants, trampolines, anything the wind can throw into the coil fins or fan grille. Some homeowners strap a sheet of plywood over the top of the unit to shield the fan from falling branches — that is reasonable if it is anchored well, but anything loosely secured becomes debris itself. A tarp or manufacturer cover is acceptable only on a unit that is fully powered off; never cover a unit that might run, because a covered running condenser cannot reject heat and will trip or damage itself. If your condenser sits low in a flood-prone yard, check whether it is anchored to its pad — hurricane straps for condensers are a small, cheap job that prevents a toppled unit, and Florida code has required tie-downs on new installations for years.

During the outage: leave it off

When the power fails, make sure the system stays off at the breaker even if the thermostat is dark. Grid restoration is messy: power often comes back in surges, drops again, and stabilizes only after several cycles. A system left switched on will try to restart at the first flicker — which is the worst possible moment. Keep the house closed up to hold the stored cooling, run battery fans if you have them, and resist the urge to open windows unless the outside air has genuinely cooled. Humidity is the real enemy of the wait: an opened-up house in post-storm Florida air loads the walls, floors, and furniture with moisture that the system will have to remove later, hours of extra runtime you can avoid by keeping the envelope shut.

After the storm: the restart is where systems die

Before restoring power to the HVAC breaker, walk the equipment. Outdoors: is the unit standing level on its pad, is the coil free of impaled debris, and — critically — is there any evidence it stood in water? A mud line, wet insulation on the refrigerant lines, silt on the pad, or debris caught in the base louvers all mean the unit flooded. A condenser that sat in water, especially brackish surge water, must not be energized until it has been inspected: submerged contactors, capacitors, and compressor terminals can short, and salt residue keeps conducting long after the water is gone. Indoors: check the air handler closet or attic for water staining and confirm the drain line outlet is not buried under storm debris. If everything looks clean and dry, restore the breaker, wait several minutes for the grid and the unit's internal timers to settle, and then call for cooling at the thermostat — one stage, not an aggressive setpoint drop. Listen for the first few minutes: grinding, buzzing, or repeated clicking is a stop-and-call signal, not a break-in period.

Flooded equipment: what insurance and code actually expect

A flooded air conditioner is not automatically a total loss, but it is automatically an inspection case. Water level matters: a unit that got wet feet is different from one submerged past its electrical box. What a proper post-flood inspection covers is the contactor and capacitor condition, compressor terminal insulation, wiring connections, and — on heat pumps and communicating systems — the outdoor control board. Document everything before cleanup: photos of the mud line on the unit, the surrounding yard, and any debris damage support both insurance claims and permit questions if replacement is needed. Be wary of any contractor who quotes a full system replacement from the curb without opening the unit; be equally wary of anyone willing to just flip a flooded unit back on to 'see if it runs.' Both shortcuts get expensive.

Generators and air conditioning: size honestly

Every hurricane season we see systems damaged by undersized portable generators. An air conditioner's compressor draws several times its running current at the moment it starts, and a generator that cannot supply that inrush delivers a voltage sag instead — the same brownout condition that stalls and overheats compressors. Most portable generators can run a refrigerator, fans, and lights but cannot legitimately start a central air conditioner, whatever the label math suggests. If storm-outage cooling matters for your household — and for homes with elderly residents or medical equipment it genuinely can — the honest solutions are a properly sized standby generator installed with a transfer switch, or a soft-start kit on the condenser that reduces the inrush a generator must supply. Both are planned, permitted work for the off-season, not the week a storm has a name.

Inverter air conditioners, starting current and backup power

ENERGY STAR explains the difference using room air conditioners: a conventional compressor works like an on/off switch, either on at maximum capacity or off, while a variable-speed compressor's motor speed can fluctuate in response to the cooling needs of the room. A 2015 test report prepared for Lawrence Berkeley National Laboratory describes the ductless inverter air conditioners it tested the same way: they adjust the rotation speed of the compressor to provide only enough cooling capacity to meet demand.

The same report measured start-up: each of the seven units displayed relatively low inrush currents compared to conventional residential air conditioners, and their compressors typically ramped up slowly over roughly 20 to 50 seconds. None of the seven stalled in the report's undervoltage tests.

For the system you already have, sizing starts with the equipment's plate: utility guidance on the City of San Diego's website says to check the owner's manual and serial plate on each appliance for its wattage, or its amps and volts, and lists air conditioners among appliances with motors that can require more than their normal wattage when the motor starts up. The generator you pick, it adds, must have a surge rating that meets or exceeds those start-up needs. University of Florida IFAS Extension's guide to backup power for greenhouses notes that the current needed to run a motor is given on its nameplate, but the starting amperage will be from two to seven times this amount. OSHA adds: do not overload a generator, because that can lead to overheating and a fire hazard.

OSHA also says never to attach a generator directly to a home's electrical system unless a qualified electrician has properly installed it with a transfer switch; without one, the connection can energize wiring for great distances and create a risk of electrocution for utility workers. Pinellas County notes that most construction jobs that involve changing the electrical or mechanical systems of your home require a permit. Hillsborough County's residential backup generator checklist says a Florida EC or ER licensed contractor can apply for the electrical trade permit, requires electrical rough-in and final inspections, and calls for a signed and sealed load calculation for units rated less than the home's main service rating.

Ready.gov says generators and fuel should always be used outdoors and at least 20 feet away from windows, doors and attached garages, and advises installing working carbon monoxide detectors on every level of your home. OSHA warns never to use a generator indoors or in enclosed spaces such as garages, crawl spaces and basements, and notes that open windows and doors may not prevent carbon monoxide from building up when a generator is in an enclosed space.