Most 3 to 4 bedroom homes in South Florida need a 24 to 38 kW standby generator. The right size comes from a load calculation done at your home, not a square-footage chart: square footage under air, air conditioning tonnage, every electric appliance, and what must run at 2am. Nobody should size a generator over the phone.
A load calculation adds up what your home actually draws, then sizes the generator to carry it with the air conditioning running. This is what we look at on the free assessment.
Two homes with the same square footage can need different generators. The appliance list and the air conditioning decide it, not the floor plan.
Too small, it trips off. An undersized generator shuts down when two air conditioners start at the same time, which is exactly when you need it most. Then you are resetting it in the dark.
Too big, you paid for power you never use. An oversized generator costs more to buy, takes more fuel to run and needs a bigger tank to feed it.
The load calculation lands between the two. The goal is a generator that carries the whole house on a hot night with margin to spare, and nothing more.
In a South Florida home, the air conditioning is almost always the largest single load. It also runs during an outage in a way nothing else does: hours at a time, in August, with the house sealed.
Motors draw more current when they start than when they run. Two air handlers starting together is the moment an undersized generator fails. That is why tonnage matters more than square footage, and why the assessment counts every air handler, not just the main one.
| Size | Type | Typical fit |
|---|---|---|
| 18 to 30 kW | Air-cooled, Generac and Kohler | Home standby |
| 25 to 150 kW | Liquid-cooled | Large homes, homes with multiple air conditioners, and commercial |
| 200 kW to 2 MW | Industrial: Cummins, Caterpillar, Rolls-Royce MTU | Commercial and industrial buildings |
Most 3 to 4 bedroom homes land at 24 to 38 kW. That is a starting point, not a quote. Air conditioning tonnage, pool pumps, and electric ranges and dryers move the answer. The full range of what we install is on the standby generators page.
The panel does not set the kilowatts, but it decides what the generator can be connected to. A standby generator needs an automatic transfer switch at the service, and a panel that can carry what you want running during an outage.
Some older panels need attention before a transfer switch can go in. We check the panel on the same visit as the load calculation, so if it needs attention you hear it at the assessment.
Yes. Size is the first factor in the price, because it sets the equipment cost and the fuel it needs. Most whole-house installs in South Florida land between $19,000 and $28,000, installed, permitted and inspected, and the load calculation is what places your home inside that range. See how much a whole-house generator costs.
Fuel matters too. Manufacturers publish separate output ratings for the same model on propane and on natural gas, and the load calculation uses the rating for the fuel you will actually run. See propane or natural gas.
Only the factors. None of them has a number until we are standing in your home.
Most 3 to 4 bedroom homes need between 24 and 38 kW. The right size comes from a load calculation at your home that counts the square footage under air, the air conditioning tonnage and every electric appliance.
No, and we would not trust anyone who does. Two homes with the same square footage can need different generators because of air conditioning tonnage, pool equipment and electric appliances. The load calculation happens at your home on the free assessment.
Sometimes. Most 3 to 4 bedroom homes in South Florida land between 24 and 38 kW once the air conditioning and every electric appliance are counted. A smaller unit can work for a smaller home, or when fewer loads need to run during an outage.
Yes. A larger engine burns more fuel, even when the house is drawing far less than the generator can supply. That is one reason we size from a load calculation instead of rounding up: an oversized unit costs more to buy and more to feed.
Tell us on the assessment. The load calculation starts with what must run at 2am and builds from there, so the size follows what you actually need to keep on, not what the catalog says a home your size should have.
Mostly Generac and Kohler for homes, from 18 kW air-cooled units up to 150 kW liquid-cooled. We also work with Cummins, Caterpillar and Rolls-Royce MTU, including industrial units from 200 kW up to 2 MW.
