Running Central Air Conditioning on a 22kW Generator
Yes. A Generac 22kW generator comfortably runs central air conditioning systems up to 5 tons while simultaneously powering every other circuit in your home. This is the single most common question buyers ask before purchasing, and the answer is clear: the 22kW was specifically sized to handle residential AC loads alongside full household demand. Here are the exact numbers.
AC Wattage by System Size
Central air conditioner power draw varies by the tonnage (cooling capacity) of the system. A 2-ton AC unit draws approximately 2,400 running watts with a 4,000 to 5,000 watt startup surge. A 2.5-ton unit draws approximately 2,800 running watts with a 4,500 to 6,000 watt startup surge. A 3-ton unit draws approximately 3,500 running watts with a 5,000 to 7,000 watt startup surge. A 4-ton unit draws approximately 4,500 running watts with a 6,500 to 9,000 watt startup surge. A 5-ton unit draws approximately 5,500 running watts with a 8,000 to 11,000 watt startup surge.
The startup surge is the critical number because it represents the peak demand the generator must handle when the compressor kicks on. Modern Generac generators use True Power Technology and advanced voltage regulation to handle these surge demands cleanly without disrupting other devices in your home.
Real-World Load Example: 22kW with 3-Ton AC
Consider a typical 2,200 square foot home with a 3-ton AC system. The running loads are 3,500 watts for central AC, 500 watts for refrigerator, 4,500 watts for electric water heater, 600 watts for gas furnace blower, 1,000 watts for lighting throughout the house, 500 watts for router, TV, and electronics, and 300 watts for miscellaneous loads. Total running load is approximately 10,900 watts, which is only 50% of the 22kW capacity. Even when the AC compressor starts (adding a temporary 5,000 to 7,000 watt surge), the generator handles it with thousands of watts to spare.
When to Consider 24kW or 26kW Instead
The 22kW covers AC for the vast majority of homes. However, if your home has a 5-ton AC system AND an electric heat pump AND an electric water heater AND a well pump, the combined running load approaches 18,000 to 20,000 watts, leaving minimal headroom for startup surges. In these all-electric, high-demand scenarios, the Generac 24kW (Model 7261) or Generac 26kW (Model 7327) provides more comfortable margin.
Heat Pumps vs. Standard AC
If your home uses a heat pump for both cooling and heating, the winter heating draw may actually be higher than the summer cooling draw, especially in cold climates where the heat pump runs with auxiliary electric resistance heat strips. Each strip can add 5,000 to 10,000 watts to the load. If your heat pump has two stages of auxiliary heat, a 22kW generator may not cover the full heating load during extreme cold. In this scenario, a 24kW or 26kW generator ensures whole-house coverage year-round.
Load Management as a Safety Net
Generac transfer switches with load management capability can intelligently shed non-critical loads when the generator approaches capacity. This means even if your total load briefly exceeds the generator rating during a large motor startup, the system temporarily drops a pre-designated load (like the electric water heater) for a few seconds, then restores it once the surge passes. This feature provides an extra layer of assurance that the generator handles peak demand gracefully.
For most homes with standard central AC, the Generac 22kW with 200A ATS (Model 7325) is the perfect fit. Call (800) 674-9019 with your AC tonnage and we will confirm the right size in minutes. Browse the full range at our Generac home standby generators collection.