Quietest generator for a home
Among home standby generators, the lowest published running level belongs to the Cummins Quiet Connect RS30 at 60 dB(A), measured at 23 ft. For running and for the weekly exercise, Cummins publishes a single level.
The quietest standby generators
| Model | Output | Running | Exercise |
|---|---|---|---|
 Quiet Connect RS30 | 30 kW (single phase 120/240 V, 125 A NG/LP) | 60 dB(A), the one published level | not published |
 Guardian 10 kW | 10,000 W LP / 9,000 W NG | 61 dB(A) | 57 dB(A) |
 14 kW aXis Home Standby (100837) | 14,000 W LP / 12,500 W NG | 62 dB(A), the one published level | not published |
| Guardian 14 kW | 14,000 W LP / 14,000 W NG | 65 dB(A) | 55 dB(A) |
| Guardian 18 kW | 18,000 W LP / 17,000 W NG | 65 dB(A) | 55 dB(A) |
| Quiet Connect RS20A | 20 kW (240 V, 75 A NG / 83.3 A LP) | 65 dB(A), the one published level | not published |
 PowerProtect 26 kW (040806) | 26 kW LP / 24 kW NG | 65 dB(A), the one published level | not published |
| Guardian 20 kW | 20,000 W LP / 18,000 W NG | 67 dB(A) | 55 dB(A) |
 26RCA | 26 kW LP / 24 kW NG | 67 dB(A) | 56 dB(A) |
| Guardian 22 kW | 22,000 W LP / 19,500 W NG | 67 dB(A) | 57 dB(A) |
The distance is 23 ft unless the spec sheet tells you otherwise. Every one of the 18 models appears on the decibel chart.
How loud it sounds at your neighbor's window
| Model | 23 ft | 30 ft | 50 ft | 75 ft |
|---|---|---|---|---|
| Cummins Quiet Connect RS30 | 60 dB(A) | 58 dB(A) | 53 dB(A) | 50 dB(A) |
| Generac Guardian 10 kW | 61 dB(A) | 59 dB(A) | 54 dB(A) | 51 dB(A) |
| Champion 14 kW aXis Home Standby (100837) | 62 dB(A) | 60 dB(A) | 55 dB(A) | 52 dB(A) |
| Generac Guardian 14 kW | 65 dB(A) | 63 dB(A) | 58 dB(A) | 55 dB(A) |
| Generac Guardian 18 kW | 65 dB(A) | 63 dB(A) | 58 dB(A) | 55 dB(A) |
Every doubling of distance in open air takes about 6 dB off the sound level. By day, many towns cap noise near 55 to 65 dB(A) at the property line. Check your local code before choosing a spot.
Why one unit runs quieter
A few decibels come off when you use an enclosure lined with sound foam, run the engine slower in exercise mode or point the muffler away from the house. Liquid-cooled units run slower, and for their size they are often quieter. A wall or fence placed between the unit and your neighbor does more good than any spec sheet difference, provided the clearances the manufacturer requires are kept.