Cummins Quiet Connect RS20AC 20kW
#6 in 15 to 22 kWFull review
For homes with central air that want a quiet 20 kW unit with monitoring included and a service-entrance switch in the box.
Norwall $6,662.42$6,662.42
The Cummins Quiet Connect RS20AC 20kW is the better standby generator overall, rated 3.2 to 2.9. The Cummins Quiet Connect RS20AC 20kW leads on noise. The Cummins Quiet Connect RS20AC 20kW costs $185.58 less ($6,662.42 vs $6,848).
Kohler 20RCAL 20kW
#9 in 15 to 22 kWFull review
For average homes with central air that want load management in the box and Kohler’s full coverage warranty.
Norwall $6,848$6,848
Prices 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 Cummins Quiet Connect RS20AC 20kW for noise (65 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 | Cummins Quiet Connect RS20AC 20kW | Kohler 20RCAL 20kW |
|---|---|---|
| Overall rating | 3.2/5 | 2.9/5 |
| Value 35% | 28 $333 per kW ($6,662 with transfer switch, 20 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% | 58 65 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% | 29 5-year warranty | 29 5-year warranty |
Specifications
| Cummins Quiet Connect RS20AC 20kW | Kohler 20RCAL 20kW | |
|---|---|---|
| Output | ||
| Rated output, propane | 20 kW | 20 kW |
| Rated output, natural gas | 18 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 | Yes | Yes |
| Enclosure | Aluminum | Aluminum |
| Dimensions | 34.1 x 36.0 x 27.3 in | 47 x 26.0 x 32.3 in |
| Weight | 596 lb | 600 lb |
| Noise and warranty | ||
| Noise, normal operation | 65 dBA | 70 dBA |
| Noise, weekly self-test | - | 66 dBA |
| Warranty | 5 years | 5 years |