Florida is no stranger to severe storms and hurricanes that cause power outages. Having backup power to run your AC and sump pump is crucial to keeping your home safe.
Backup power is also vital for running medical devices like oxygen concentrators or CPAP machines during power outages. But you must have the correct size generator to ensure you can keep all of your major appliances and essential systems running.
You’ll know your exact generator size by the end of this guide. Speaking with a licensed local electrician from Mister Sparky is a smart move for choosing a generator that can fully meet your household needs.
Quick Takeaways
- A 14–22 kW whole-home generator is the correct size for most average-sized homes.
- A professional will size the generator by totaling the running watts and starting watts to make sure they match your home’s electrical needs.
- It’s best to size slightly larger than the minimum to avoid overloads and protect equipment.
- Professional installation is crucial to making sure the generator, transfer switch, and wiring are safely and correctly matched.
- Storm patterns, outage frequency, and fuel type all impact the generator size a Florida home requires.
The Short Answer: Most Homes Need a 14–22 kW Generator
Most homes need a generator ranging from 14 to 22 kW to run central AC, major kitchen appliances, and essential household circuits during outages.
| Generator Size | Coverage |
|---|---|
| 14–16 kW | Small home / essentials only |
| 17–20 kW | Medium home / partial backup |
| 21–22 kW | Large home / whole-home backup |
Homes in Florida often require larger generators because of the higher electrical demand created by the constant use of central ACs, pool equipment or heat pumps.
How to Determine the Generator Size Your Home Needs
The best way to determine the size generator you need is to follow the same steps our technicians take. We consider multiple factors to precisely match the size to your home’s unique power requirements.
Step 1—Identify the Essential Appliances You Want Powered
Do a walkthrough of your home to write down all of the appliances you want to keep powered during an outage.
- HVAC
- Refrigerator/freezer
- Well pump or sump pump
- Lighting
- Medical equipment
- Wi-Fi/electronics
- Water heater
- Stove
- Dryer
Step 2—Calculate Running Watts and Starting Watts
Every device or appliance that you want to keep powered has a starting wattage and a running wattage. You add all of the running watts together to know your total continuous power demand. Then you take note of the single highest starting watt to account for the startup surge.
| Appliance | Running Watts (avg) | Starting Watts (avg) |
|---|---|---|
| HVAC (3–4 ton AC) | 3,500 watts | 6,000 watts |
| Refrigerator/Freezer | 250 watts | 700 watts |
| Well Pump/Sump Pump | 800 watts | 1,500 watts |
| Lighting (LED/CFL mix) | 200 watts | 250 watts |
| Medical Equipment | 300 watts | 350 watts |
| Wi-Fi/Electronics | 250 watts | 300 watts |
| Electric Water Heater | 2,800 watts | 2,900 watts |
| Electric Stove/Oven | 2,400 watts | 2,600 watts |
| Electric Dryer | 3,800 watts | 4,000 watts |
| TOTAL WATTAGE | 14,300 watts | 18,600 watts |
In the example above, the total running wattage requirement is 14,300. The highest starting watt requirement is 6,000. So the maximum load that the generator needs to be able to handle at any given time is 20,300 kW.
A 22 kW or 24 kW generator would be sufficient to run all of the systems safely.
Step 3—Add a Safety Margin (25%–40%)
Adding a 25–40% safety margin to your total wattage requirements ensures the generator doesn’t constantly run at max load. This is why we suggested a 22-24 kW generator in the example above. The extra capacity helps the generator use fuel more efficiently and operate with less wear, vibration, and noise.
Step 4—Match the Generator to Your Electrical Panel & Fuel Source
Most homes in Florida have 150A or 200A service, meaning they already have the wiring capacity needed to support a 14-24 kW generator. We may have to make upgrades to your panel if the existing components are outdated, undersized, or not rated for the generator you want installed.
Lastly, you need to consider the generator’s fuel source. Units running on natural gas typically produce less wattage than the same models operating on propane.
Generator Size Recommendations by Home Type
Your home’s size plays a large role in choosing the right size generator. For homes in Florida, the following ranges usually apply.
| Home Size | Recommended Generator Size |
|---|---|
| Small Homes (Under 1,200 Sq Ft) | 8–12 kW for essentials 12–14 kW for near-whole-home coverage |
| Medium Homes (1,200–2,000 Sq Ft) | 14–18 kW depending on AC tonnage and appliance mix |
| Larger Homes (2,000–3,000+ Sq Ft) | 18–22 kW or larger |
Homes with multiple cooling systems (central setups or heat pumps) and those using pool pumps may need a 22 to 26 kW generator.
Florida-Specific Factors That Affect Generator Size
Florida is a state with high heat and heavy humidity. These weather elements influence choosing a generator because they lead to large cooling loads. Long storm seasons causing multiple outages mean your generator must be sized to run for extended periods without strain.
Permit requirements in Florida for installing a whole-home generator range from about $150 to $500. We can help you handle the permitting process so you don’t run into delays or compliance issues.
Common Mistakes When Choosing a Generator Size
Here are the common missteps homeowners make when deciding on a generator and how to avoid them:
- Picking a generator too small: Make sure to size for peak summer demand
- Missing appliance startup wattage: Account for all surge demands
- Ignoring future electrical needs: Plan for added appliances
- Trusting generic calculator estimates: Use a tailored load review
- Misreading panel amperage requirements: Match unit to panel rating
- Skipping a licensed electrician: Confirm sizing with a pro
Why Proper Sizing Matters for Safety & Performance
Proper sizing does much more than make sure you have a generator that can keep your home’s essential systems running during power outages.
- Keeps major appliances safe
- Stops circuits from overloading
- Helps the generator last longer
- Meets NEC rules and local standards
- Protects sensitive home electronics
When You Should Choose a Whole-Home Generator
A whole-home generator makes the most sense in these scenarios:
- Living in Daytona’s high-risk coastal zones
- Reliance on medical or life-safety equipment
- Need to protect valuable home electronics
- Wanting stronger insurance and property benefits
- Desire for full comfort during long outages
Frequently Asked Questions
What size generator do I need to run my whole house?
Most homes in Florida need a 14–22 kW generator to run their AC and other appliances without causing overload issues.
Can a 12 kW generator run central air?
You may be able to run a 2–2.5 ton AC with a 12 kW generator. Larger units almost always need a higher-capacity standby generator.
How many watts does a 3-ton AC use when starting?
A 3-ton AC will normally produce about 6,000 to 8,000 watts to start and then about 3,000 to 4,500 watts as it runs.
Is it better to oversize or undersize a generator?
It’s okay to slightly oversize a generator because you want to account for future electrical needs. But undersizing will lead to issues with overloads and frequent shutdowns.
Do Daytona homes need larger generators because of hurricanes?
Because Florida homes often experience extended power outages, they usually need larger generators to keep major systems running without strain.
Ready to Find the Right Generator Size? Call Mister Sparky of Daytona, FL
Mister Sparky is Daytona’s on-time electrician. We arrive in stocked trucks to fix most electrical problems on the spot. We’ll help you choose the right size generator for your home and even install it for you.
Our licensed electricians are very familiar with Florida’s electrical codes and how they impact generator sizing. Call now for a free or low-cost load-calculation visit.