22 kW generator
Propane power for a 22 kW standby unit such as Generac Guardian 22 kW reaches 22,000 W, and natural gas power is about 19,580 W. Other models rate a little differently. With natural gas, it can cover a home of up to 3,500 sq ft that has 3-ton central air.
For a natural gas install, the 22 kW begins at $10,269 in Arkansas and climbs to $12,569 in Oregon. Labor costs by state are based on BLS wages, May 2025.
Is 22 kW the right size for your house? Work through three questions, including your AC or well pump start.
What a 22 kW generator runs
| Loads running together | Running | Peak at a motor start | Natural gas | Propane |
|---|---|---|---|---|
| Essentials | 4.5 kW | 5.6 kW | runs | runs |
| Essentials and a 1 hp well pump | 6.5 kW | 8.5 kW | runs | runs |
| Essentials and a 2-ton central AC | 7.0 kW | 9.0 kW | runs | runs |
| Essentials and a 3-ton central AC | 8.0 kW | 10.5 kW | runs | runs |
| Essentials and a 4-ton central AC | 9.5 kW | 12.5 kW | runs | runs |
The essentials list covers a microwave, lights, TV, a router, the furnace blower, a fridge, a freezer and a 1/2 hp sump pump. The "runs" figure means the load you run stays below 80% of the rating, and on top of that the largest motor start is covered.
| Whole house load | Natural gas | Propane |
|---|---|---|
| No central air | up to 5,000 sq ft | up to 5,000 sq ft |
| Central AC, 3 ton | up to 3,500 sq ft | up to 5,000 sq ft |
| Central AC, 4 ton | up to 2,500 sq ft | up to 4,000 sq ft |
The whole house rows use NEC 220.83, where outlets and lights count 3 VA per sq ft, and kitchen and laundry circuits and gas heat are added, while an electric range, dryer or water heater is excluded. Check your house.
Fuel use each hour
| Load | Natural gas | Gas cost | Propane | Propane cost |
|---|---|---|---|---|
| 25% | 143 cu ft | $3.12 | 1.84 gal | $5.04 |
| 50% | 204 cu ft | $4.47 | 2.53 gal | $6.91 |
| 75% | 266 cu ft | $5.82 | 3.21 gal | $8.78 |
| 100% | 327 cu ft | $7.17 | 3.90 gal | $10.65 |
The Guardian 22 kW numbers at half load and full load come from Generac's fuel table, and 25% and 75% read in between. The costs are based on EIA US average prices.
Hours per propane tank
| Tank | 25% load | 50% load | Full load |
|---|---|---|---|
| 120 gal | 52 h | 38 h | 25 h |
| 250 gal | 108 h | 79 h | 51 h |
| 500 gal | 217 h | 158 h | 103 h |
| 1,000 gal | 434 h | 316 h | 205 h |
A tank fills only to 80% of its capacity.
Cost once installed
| Line, 22 kW | Natural gas | Propane | Basis |
|---|---|---|---|
| Generator | $6,309 | $6,309 | List price Generac posts for the 22 kW bundle, with the switch removed. |
| Transfer switch | $1,060 | $1,060 | the difference in Generac's listings, with the switch and without it |
| Electrician: switch, wiring, start-up | $3,000 to $5,500 | $3,000 to $5,500 | install ranges as published, using $34.37 an hour (BLS), the US average wage |
| Fuel line | $500 to $2,000 | $800 to $2,500 | gas line runs from the meter; propane line runs from the tank |
| Pad and permit | $300 to $1,200 | $300 to $1,200 | composite pad or slab, local fees |
| Installed | $11,169 to $16,069 | $11,469 to $16,569 | propane leaves out the tank |
22 kW against the other brands
| Brand | Model at 22 kW or next up | List price | Installed, natural gas | Page |
|---|---|---|---|---|
 Generac | Guardian 22 kW, with switch | $7,369 | $11,169 to $16,069 | Generac cost |
 Kohler | 26 kW 26RCA, with switch | $7,546 | $11,346 to $16,246 | Kohler cost |
Every unit gets four extra items in its installed price: the electrician, a gas line, a pad and a permit. A unit sold without a switch also has Generac's switch price for the closest size added on top. The list prices are published on Generac's own pages and on Kohler's own pages. For Cummins, Briggs & Stratton and Champion, dealers handle the sale and quote the unit: Cummins generator costs, Briggs & Stratton generator costs, Champion generator costs.
Sizes: 18 kW unit 24 kW unit All the sizes