Which generator setup actually runs the air conditioner, and which one only looks like it will

The week the county was dark

Helene in September 2024 took power from more than 99 percent of Columbia County, and on the co-op lines that run through pine country to the acreage homes, restoration took days. Idalia the year before had done a smaller version of the same thing. By the second night of Helene, generators were running in driveways from Fort White to Olustee. Refrigerators hummed, phones charged, a fan moved air in the living room. The heat pumps stayed silent.

In most of those houses the generator could have run the air conditioning, or at least the heat in a winter outage. It was connected in a way that made that impossible. This guide compares the three ways Columbia County homes connect a generator and what each means for the heating and cooling.

Setup one: a portable and a handful of cords

The most common arrangement in the county. A portable generator of modest size on the driveway, extension cords through a window to the refrigerator, a freezer, a lamp, a fan and the phone chargers.

What it runs: Anything with a plug.

What it cannot run: The heat pump, in any form. Both halves of the system are hard-wired on their own circuits at the panel, and a cord cannot reach them. A window unit with a plug, yes, if the generator is big enough to start it.

The honest assessment: This setup keeps food cold and lets people sleep with a fan. It does not condition the house. For a family that can tolerate a few hot nights, it may be enough; for anyone with health concerns or a winter outage on a 25-degree night, it is not.

Setup two: a portable on a manual transfer switch

A larger portable generator feeding the house through an inlet box on the exterior wall and a manual transfer switch or interlock at the main panel, installed by an electrician. When the power fails, the homeowner starts the generator, plugs in one heavy cord, throws the transfer switch and chooses which circuits to power.

What it runs: Selected circuits in the house, including hard-wired ones, up to the generator’s capacity. With care, that can include the heat pump.

The catch: The heat pump’s starting draw. A compressor pulls several times its running current for an instant at start. A generator that handles the running load comfortably can stall at that surge. The fix is either a generator sized for the locked-rotor amps on the condenser nameplate or a soft-start device on the compressor that cuts the surge to a fraction. Soft-start kits are the single most useful HVAC addition for a household in this setup.

The other catch: Sequencing. The well pump, the heat pump and an electric water heater all have big draws and cannot all start together. The homeowner manages this by hand, turning on circuits in order. It works, and it requires someone home who knows the order.

Setup three: a standby generator with automatic transfer

A permanently installed generator on a pad, fueled by propane across most of the county, or by Lake City Utilities gas for the handful of houses near Lake DeSoto with a main at the curb, with an automatic transfer switch that senses the outage, starts the unit and switches the house over in seconds. Often paired with a load-management module that sheds and restores big loads in sequence.

What it runs: The whole house, or the part of it the system was designed for, without anyone home.

What it needs from the HVAC side: A load calculation that includes the heat pump’s starting draw, and often a soft-start device for the compressor so the standby unit can be sized sensibly. In winter, the air handler’s electric strips are the largest load in the house and must be counted; many standby systems are set to lock out the strips and let the heat pump alone carry the heating during an outage, which works for all but the coldest hours.

The honest assessment: The only setup that keeps a house conditioned through a multi-day outage without someone managing cords and switches. Also the most expensive, and the one that most needs the HVAC contractor and the electrician to talk to each other before it is installed.

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The three setups, side by side

What the heat pump side contributes

Cook’s does not install generators or transfer switches; that is an electrician’s work. What we do is the HVAC half of the plan:

• Read the condenser’s nameplate for running and locked-rotor amps so the generator and switch are sized on real numbers.
• Fit the compressor with a soft-start device where it lets a smaller generator do the job.
• Set up the thermostat and air handler so strip heat can be locked out on generator power in winter.
• Add surge protection at the disconnect, because the moment utility power returns is as hard on the equipment as the storm was.
• Check the system after the outage, since running on a generator that sagged under load is tough on motors and boards.

Winter outages are the hard case

Everyone plans for a summer hurricane. The outage that catches Columbia County off guard is a hard freeze or ice event that drops a Clay Electric feeder on a 22-degree night, the long rural kind running out to Lulu or east along US 90 past Olustee and the edge of the Osceola National Forest, where a crew may need a while to reach the break. The heat pump can carry a house through that on a generator; the electric strips mostly cannot, because fifteen kilowatts of resistance heat is more than most residential generators have to give. Planning for winter means planning for the heat pump to run alone, with the strips locked out, and that is a setting we configure.

From Palm Coast, after the lines come back

Cook’s works the Columbia County route through storm recovery out of Palm Coast, 37 Fairmont Ln, about two hours and twenty-five minutes from Lake City, and the extended hours add nothing to the bill. Soft-start kits and surge protectors ride on every truck. Lennox installed, every brand repaired, and a technician who will gladly talk to your electrician before the generator is ordered.