How does Kohler measure generator noise?
Kohler measures generator noise 23 ft (7 m) from the unit and prints the quietest of 8 points around it, once for engine exercise and once for normal operation. Every current Kohler home generator sheet carries the same footnote.
That footnote reads "Lowest of 8 points measured around the generator. Sound levels at other points around generator may vary depending on installation parameters." The printed number belongs to whichever side of the enclosure read quietest, and Kohler never says which side that was.
Load is the other variable. The 10RESV, 12RESV, 24RCLA, 30RCLA and 38RCLC sheets add "with no load", so even their normal-operation figure describes an engine running without the house on it. The 14RCA, 20RCA, 26RCA, 48RCLC and 60RCLB sheets name no load at all.
A quietest-point figure flatters the machine, so setting a Kohler number beside another maker's takes care; comparing decibel ratings sets out which details must match. Within Kohler, distance and position match on every sheet, which is why the tables below line the models up.
How loud is a Kohler air-cooled generator?
A Kohler air-cooled generator lists 56 to 66 dB(A) during weekly engine exercise and 67 to 70 dB(A) during full-speed diagnostics and normal operation, on spec sheets measured at 23 ft (7 m) from the quietest of 8 points.
| Model | Output, LP / NG | Exercise | Full speed and normal operation | Load on sheet | MSRP |
|---|
| 26RCA | 26 / 24 kW | 56 dB(A) | 67 dB(A) | Not stated | $7,546 |
| 14RCA | 14 / 12 kW | 63 dB(A) | 69 dB(A) | Not stated | $5,098 |
| 10RESV | 10 / 9 kW | 64 dB(A) | 69 dB(A) | No load | $3,946 |
| 12RESV | 12 / 11 kW | 64 dB(A) | 69 dB(A) | No load | $4,384 |
| 20RCA | 20 / 18 kW | 66 dB(A) | 70 dB(A) | Not stated | $6,016 |
Rows run from the lowest exercise figure up. For the 10RESV and 12RESV, which share one sheet, the table shows the lowest-point pair; their 8-point averages are 67 and 71. Each L version, packaged with a Model RXT transfer switch, keeps its generator's figures and costs $539 to $969 more.
Exercise noise does not follow engine size in this range. The 26RCA, the biggest air-cooled Kohler, has the lowest exercise figure, 7 dB(A) under the 14RCA, while the 20RCA, one size down, has the highest. At full speed the spread narrows to 67 through 70.
How loud is a Kohler 26kW generator?
The Kohler 26RCA is rated at 56 dB(A) in engine exercise and 67 dB(A) in full-speed generator diagnostics and normal operation, 23 ft (7 m) out, from the quietest of 8 points. Its product page prints the same two figures.
Its test routine also differs from the rest of the air-cooled range. The sheet lists a "New 90-second Eco Exercise with complete system diagnostics (factory default setting)", which it says "Minimizes sound disruption", next to the 20-minute unloaded and full-speed modes that the other air-cooled sheets describe.
The product page ties that mode to the number: "The 90 second eco-exercise option operates at the volume of a conversation [56dB(A) Exercise]. No air-cooled generator is quieter." The sheet itself does not say which exercise mode produced the 56, or whether a 20-minute test would read the same.
How loud is a Kohler 20kW generator?
The Kohler 20RCA lists 66 dB(A) during weekly engine exercise and 70 dB(A) during full-speed diagnostics and normal operation on its spec sheet, at 23 ft (7 m). Its product page shows 64 and 69 instead.
Its sheet is also unclear about position. The sound sentence opens "Model 20RCA average sound levels are 66 dB(A)", yet the asterisk on that sentence leads to the usual "Lowest of 8 points" footnote. A figure cannot be both an average and the quietest point, and Kohler does not say which it meant.
Read either way, the 20RCA carries the loudest figures of any air-cooled Kohler. For $1,530 more, the 26RCA lists 10 dB(A) less in exercise and 3 less at full speed, with 6 kW more on propane.
How loud is a Kohler liquid-cooled generator?
A Kohler liquid-cooled generator is rated at 52 or 61 dB(A) in engine exercise and at 60 or 61 dB(A) in normal operation, 23 ft (7 m) out and from the quietest of 8 points. Engine size decides which pair a model gets.
| Model | Output, LP / NG | Engine | Exercise | Normal operation | Load on sheet | MSRP |
|---|
| 24RCLA | 24 / 21 kW | 2.2 L in-line 4 | 52 dB(A) | 60 dB(A) | No load | $17,900 |
| 30RCLA | 30 / 30 kW | 2.2 L in-line 4 | 52 dB(A) | 60 dB(A) | No load | $20,399 |
| 38RCLC | 38 / 38 kW | 2.2 L in-line 4 | 52 dB(A) | 60 dB(A) | No load | $22,949 |
| 48RCLC | 48 / 48 kW | 6.2 L V-8 | 61 dB(A) | 61 dB(A) | Not stated | $25,703 |
| 60RCLB | 60 / 58 kW | 6.2 L V-8 | 61 dB(A) | 61 dB(A) | Not stated | $28,304 |
All five turn at 1,800 rpm. The three 2.2 L models print one identical pair whatever their output, so on Kohler's figures the step from 24 to 38 kW adds no noise, only $5,049 and 110 lb of shipping weight.
The V-8 models are the odd ones. Their sheets give 61 dB(A) for exercise and normal operation alike, with no load condition, so the weekly test is listed as loud as an outage. Their product pages show 57 in exercise and still carry the line "Exercises as quiet as the rain [52dB(A) Exercise]".
What separates Kohler's air-cooled and liquid-cooled generators?
Kohler's air-cooled generators run V-twin engines at 3,600 rpm, its liquid-cooled ones in-line 4 or V-8 engines at 1,800 rpm, and the 2.2 L liquid-cooled sheets carry the lowest figures Kohler prints.
Kohler's explanation appears on the liquid-cooled product pages: "Lower rpm means quieter and longer lasting." Those sheets add "Electronically controlled fan speeds minimize generator set sound signature", a feature the air-cooled sheets do not list.
We still keep the two groups in separate tables. Three liquid-cooled sheets say "with no load", while three of the five air-cooled models give no load condition at all, so 52 beside 56 is not a like-for-like gap.
The lower figure also costs a great deal. The 24RCLA is $17,900 and ships at 1,260 lb wet, against $7,546 and 670 lb for the 26RCA, which makes liquid cooling a choice for long outages or loads beyond 26 kW more than a quiet upgrade.
Why do Kohler's spec sheets and product pages list different decibels?
Kohler's spec sheets and product pages disagree on seven of the ten current models. Only the sheets give a distance, a measuring position and sometimes a load, so every ranked figure on this page comes from a sheet.
- 14RCA: sheet 63 and 69, page 63 and 67.
- 20RCA: sheet 66 and 70, page 64 and 69.
- 24RCLA: sheet 52 and 60, page 54 and 61.
- 30RCLA and 38RCLC: sheet 52 and 60, page 54 and 62.
- 48RCLC and 60RCLB: sheet 61 and 61, page 57 and 61.
The 26RCA's page and sheet match. So do the 10RESV and 12RESV pages, which print the sheet's 8-point average, 67 and 71, rather than its lowest-point pair.
The pages label their rows "Sound Output During Weekly Exercise" and "Sound output During Full-speed Operation", with no distance or position beside them. A page figure stripped of those details cannot be checked against anything, so we set the page figures aside.
How long does a Kohler generator exercise?
A Kohler air-cooled generator's standard exercise runs 20 minutes unloaded, according to the 14RCA, 20RCA and 26RCA sheets, and the 26RCA defaults to a 90-second Eco Exercise instead.
Those three sheets offer "Weekly, bi-weekly, or new monthly exercise intervals", along with 20-minute full-speed runs, unloaded or, with a Model RXT transfer switch, loaded. The 10RESV, 12RESV and liquid-cooled sheets list the same three modes without a run time.
On the air-cooled sheets, only the lower figure belongs to exercise. The higher one covers "full-speed generator diagnostics and normal operation", so a full-speed test falls under the louder number.
Kohler's Energy Management app brochure says owners can "Schedule or start an exercise (test cycle) anytime and from anywhere". That makes it simple to move the weekly run to an hour when the street is at work.
How do Kohler's decibel ratings compare with Generac's?
Kohler's and Generac's ratings share a distance, 23 ft (7 m), but not a position: Kohler prints the quietest of 8 points around the generator, and Generac measures from the front.
Both makers claim the lead. Kohler's liquid-cooled pages say "No residential generator is quieter", and Generac makes a similar boast for its Quiet-Test mode. A quietest-side reading and a front reading need not describe the same sound, so neither boast can be tested from the published sheets.
A gap of a few decibels between a Kohler and a Generac therefore proves nothing in either direction. Generac's own sheet figures are on the Generac generator decibels page.
How does Kohler reduce generator noise?
Kohler reduces generator noise with lined enclosures and a critical silencer on every home model, plus electronically controlled fan speeds on the liquid-cooled ones, according to its spec sheets.
The air-cooled sheets list "Sound-deadening, flame-retardant foam per UL 94, class HF-1", in an aluminum enclosure on the RCA models and a steel one on the 10RESV and 12RESV. The liquid-cooled sheets describe an enclosure that "uses acoustic insulation" and an "Internally mounted critical silencer".
Placement does the rest. Since the published figure comes from the quietest side, ask the dealer which face of your model that is and point it toward the nearest neighbor. Local limits and setback rules are covered in generator noise and neighbors.
