For homes with central air that want whole-house backup for the least money and a long parts warranty.
Norwall $5,699The Champion 22kW aXis is the better standby generator overall, rated 4.2 to 2.9. The Champion 22kW aXis leads on warranty, value and noise. The Champion 22kW aXis costs $1,149 less ($5,699 vs $6,848).
For average homes with central air that want load management in the box and Kohler’s full coverage warranty.
Norwall $6,848Prices were last checked November 1, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Champion 22kW aXis for warranty (10-year warranty vs 5-year warranty), value ($259 per kW ($5,699 with transfer switch, 22 kW on propane) vs $342 per kW ($6,848 with transfer switch, 20 kW on propane)) and noise (67 dBA rated in normal operation vs 70 dBA rated in normal operation).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 15 to 22 kw standby generator; a clear win is highlighted. How we rank explains each one.
| Factor weight | Champion 22kW aXis | Kohler 20RCAL 20kW |
|---|---|---|
| Overall rating | 4.2/5 | 2.9/5 |
| Value 35% | 67 $259 per kW ($5,699 with transfer switch, 22 kW on propane) | 24 $342 per kW ($6,848 with transfer switch, 20 kW on propane) |
| Transfer switch 15% | 100 includes a 200 A transfer switch | 100 includes a 200 A transfer switch |
| Noise 15% | 42 67 dBA rated in normal operation | 17 70 dBA rated in normal operation |
| Power quality 10% | 83 under 5% THD | 83 under 5% THD |
| Warranty 25% | 100 10-year warranty | 29 5-year warranty |
Specifications
| Champion 22kW aXis | Kohler 20RCAL 20kW | |
|---|---|---|
| Output | ||
| Rated output, propane | 22 kW | 20 kW |
| Rated output, natural gas | 19.8 kW | 18 kW |
| THD | Under 5% | Under 5% |
| Engine | 999 cc | 999 cc |
| Engine speed | 3,600 rpm | 3,600 rpm |
| Install | ||
| Transfer switch | Included, 200 A | Included, 200 A |
| Load management | No | Yes |
| Remote monitoring | No | Yes |
| Enclosure | Steel | Aluminum |
| Dimensions | 54 x 30.3 x 43.9 in | 47 x 26.0 x 32.3 in |
| Weight | 634.3 lb | 600 lb |
| Noise and warranty | ||
| Noise, normal operation | 67 dBA | 70 dBA |
| Noise, weekly self-test | - | 66 dBA |
| Warranty | 10 years | 5 years |
