Keeping the AC running when the power is out

The CDC is direct about heat and older adults. People 65 and older adjust less well to sudden temperature changes, are more likely to have chronic conditions that change the body's response to heat, and more often take medicines that affect temperature control or sweating. In very hot weather, the CDC advises older adults to stay in air-conditioned buildings as much as possible and not to rely on a fan as the main way to cool off. It also asks caretakers to check on older people at least twice a day.

The National Weather Service lists the warning signs of heat stroke: a body temperature above 103 F, confusion, slurred speech, and hot, red skin. Its instruction is to call 911 or get the person to a hospital immediately.

Many Villages residents are well past 65, and many manage heart conditions, diabetes or medicines that the CDC's list describes. Hurricane season runs from June 1 to November 30, with its peak on September 10, squarely in the hottest part of a Florida year. Milton's local outages lasted about four days. Irma's peak left 38.9 percent of Sumter County accounts out in September 2017.

That combination is why air conditioning sits at the top of most generator load lists here, next to medical equipment and the refrigerator. It is also why a fan on a battery or a portable generator, which cannot run central air, is not really a cooling plan for an older household.

There is no good public study of how fast a private Florida home heats up without power, so this page does not guess. The evidence that exists comes from nursing homes, and it is sobering. The next section explains what Florida learned.

Put cooling at the top of your household's must-run list

After Hurricane Irma made landfall on September 10, 2017, the Rehabilitation Center at Hollywood Hills in Broward County lost air conditioning for three days. A judge later found the power loss came from a dislodged fuse on a transformer on a utility pole. Authorities linked as many as 12 deaths to the heat, and the state issued a final order revoking the facility's license in January 2019.

It was not only one building. A JAMA Health Forum study, summarized by WUSF, found Florida nursing home deaths rose 25 percent in the week after Irma's landfall and 10 percent over 30 days. About 28,000 residents age 65 and older were in facilities that lost power, and most of the added deaths were tied to heat after air conditioning failed.

Florida responded in 2018. Governor Rick Scott signed bills on March 26, 2018 ratifying two rules, one for nursing homes and one for assisted living facilities. Both require an alternative power source and enough fuel to keep indoor temperatures at or below 81 F for at least 96 hours after primary power is lost. The ratified nursing home rule requires at least 30 net square feet per resident in the cooled area and at least 72 hours of fuel stored on site, with piped natural gas counting as on-site fuel. The bill passed 35 to 0 in the Senate and 113 to 0 in the House. The nursing home rule was amended again effective January 25, 2026.

Two points keep this in proportion. These rules apply to licensed facilities, not private homes; no rule requires a homeowner to have a generator. But the standard is a useful benchmark for your own planning. The state decided that frail older adults need cooling at 81 F or below, for four days, with the fuel to back it. Four days is also about how long Milton's local outages lasted.

Use 81 F for four days as your own household benchmark

A central air conditioner is easy to run once it is running, and hard to start. The compressor motor draws a short, large surge as it starts, called locked-rotor amps, before settling to its running current.

Goodman's spec sheet for its GLXS3B heat pump series gives clear examples. Converted at 240 volts:

• 3-ton unit: about 13.4 amps running, about 3.2 kVA. Locked-rotor amps 83.3, about 20.0 kVA at the instant of starting.
• 5-ton unit: about 23.9 amps running, about 5.7 kVA. Locked-rotor amps 148.0, about 35.5 kVA to start.

The starting surge on the 3-ton unit is more than six times its running load. Generac's sizing guidance gives the general rule: single-phase induction motors, such as refrigerator compressors and pumps, need 3 to 5 times their running watts to start. A refrigerator listed by DTE Energy at about 750 watts running needs about 2,250 to start.

That surge is what decides generator size for most Florida homes. A generator big enough to run the whole house on paper may still sag or trip if two compressors try to start at once, or if the AC starts while the range and dryer are already running.

Utility planning guides are more conservative than nameplates. DTE lists a 3-ton central AC at 6,000 watts running with a starting factor of 3, far above the Goodman nameplate math. Your installer reads the actual nameplate on your condenser, not a chart, which is why the in-home visit matters.

The good news: every major maker now builds tools to manage that surge, so you do not have to buy a generator sized for the worst moment of every day. The next section covers them. To see how your loads add up, try the sizing guide.

Photograph your condenser's nameplate before the estimate visit

Two tools let a generator carry central air without being oversized for the starting surge.

Load management is built into most current standby systems. It watches the generator's output and decides what can start and when:

• Generac's service-rated transfer switch for the 26 kW Guardian manages up to four air conditioning loads with no added hardware. Its Smart Management Modules handle up to eight more large 240-volt loads, managing them at startup and shedding them so the generator can recover if it is overloaded. Generac says these modules can often reduce the system size and cost.
• Kohler's load management can handle up to six residential loads, including two independent air conditioners, adding and shedding by priority.
• Cummins lists control of up to four loads on its RS20A, and says the unit can start a 5-ton air conditioner under full pre-load.

In practice, load management means the AC never starts at the same moment as the dryer, a second AC waits its turn, and the pool pump drops off when the house needs the room. You rarely notice it working.

A soft start is a small device added to the compressor that is meant to ramp the motor up more gently and lower the starting surge. Many installers suggest one on homes where the AC is the deciding load. Whether it suits your system depends on the compressor model and the manufacturer's guidance, so ask your installer and your HVAC company before adding one.

Both tools also stretch fuel. A generator that is not oversized for one surge runs nearer an efficient share of its rating the rest of the day. On a propane home with a 120-gallon above-ground tank, that matters; see generator fuel runtime.

Ask your installer to price load management on every AC system

Most generator sizing in The Villages starts with one question: how many air conditioning systems, and how big? The answer shapes everything else.

A practical way to think about it:

1. Start with the must-run loads. Medical equipment, the refrigerator and freezer, lights, the garage door, and internet.
2. Add cooling. One system for a smaller villa, or every system for a larger designer home. Note each tonnage from the nameplate.
3. Decide how much else runs at the same time. The range, dryer, water heater and pool pump can be managed rather than sized for.
4. Choose whole-house or managed essentials. A larger unit with load management runs the home nearly as normal. A smaller unit with tighter load management cools the core rooms and keeps fuel use lower.

On a 26 kW Generac, fuel use at half load is 2.06 gallons of propane or 188 cubic feet of natural gas an hour, rising to 3.63 gallons or 333 cubic feet at full load. A system sized so that the AC and essentials run near half load is often the best long-outage choice, especially on propane, where the district ARC manuals cap an above-ground tank at 120 gallons.

Courtyard and patio villas bring placement limits as well as sizing ones; see the courtyard villa page. Every generator in The Villages also goes through ARC review for placement, screening and exhaust; see ARC approval.

The sizing guide lets you enter your systems and priorities and see a starting range. Your installer confirms it against your panel and nameplates at the free in-home estimate. Costs for typical installs are on whole-home generator cost.

Run the sizing guide with every AC system included

Once the generator is in, a few habits keep the house cool and the fuel lasting through a multi-day outage.

• Set a sensible thermostat. A few degrees above your normal setting still keeps the house well below the 81 F benchmark Florida sets for nursing homes, and every degree saves fuel.
• Cool the rooms you use. Close doors and vents to guest rooms and keep curtains drawn on the sunny side in the afternoon.
• Run big appliances one at a time and in cooler hours, so load management rarely has to shed the AC.
• Skip the extras. The pool pump, garage refrigerator and outdoor lighting can wait.
• Use ceiling fans with the AC, not instead of it. The CDC warns against relying on a fan alone in very hot weather.
• Watch the people, not just the thermostat. Check on older relatives and neighbors twice a day, as the CDC suggests, and know the NWS signs of heat stroke.

Keep the generator itself healthy too. Generac asks for a 30-minute shutdown after every 24 hours of continuous running to check the oil. Plan that pause for early morning, when the house has cooled overnight and will hold its temperature. The maintenance page has the full routine.

If anyone in the home uses oxygen or other powered equipment, read backup power for medical equipment as well. Cooling and medical care work together: heat raises breathing strain, and the FDA's room-temperature limit for insulin is 86 F.

When you are ready, one request matches you with a licensed local installer for a free in-home estimate. Bring the condenser nameplate photo and your must-run list.

Request a free estimate built around keeping the house cool