YOUR GUIDE TO QUIET PORTABLE GENERATORS


A typical untreated portable genset may be as loud as a lawn mover. It may be acceptable for a few minutes, but not for long periods of time. It does not make sense to buy such a device if you or your neighbors won't be able to work or sleep because of it. This review will tell you what you need to know about genset noise and help you choose the quietest one. I'll start with a quick reference that explains how sound is measured.
However, if you are not interested in the technical stuff and just want to know what is the quietest generator, you may just scroll down to the generators noise rating chart.

NOISE MEASUREMENT



Noise levels are usually measured in decibel (dB). There is common confusion about its definition. If you measure acoustic power W1 in watts, then dB=10×log(W1/Wo), where Wo is a reference level equals to 1 picowatt. Microphones normally respond to the sound pressure rather than power. Since the power varies with the square of the pressure P, then dB=20×log(P1/Po), where P1- rms sound pressure in Pascal being measured, Po- a reference level. By convention, 0 dB sound pressure reference level is a typical threshold of human hearing. Since human ear has different sensitivity to different frequencies, the noise levels are often measured with a so-called A-filter whose frequency response is similar to that of the our ear. These frequency-weighting results are stated in dB(A) or dBA.

UNDERSTANDING NOISE LEVELS

Home generator guide 2015


If you wonder how loud is for example, 65 dB, here are typical dBA levels associated with various sources:

Gas lawn mower at 3 ft – 90-100
Heavy street traffic at 15 ft – 85
TV at moderate volume 65
Normal conversation – 60
Library – 35

Most places throughout the U.S. have local noise ordinances, which set the allowable sound level that can cross property lines. For example, typical numbers for continuous noise in residential urban areas are 57 dBA daytime and 47 dBA nighttime. You need to make sure your device does not exceed these levels. When you run a genset during a blackout, you don't want your jealous neighbors call an inspector.

Of course, sound levels depend on the distance from the source. For example, every time the distance doubles, the pressure level decreases by half, i.e. by 6 dB.

COMPARING LOW-NOISE GENERATORS



It is customary to measure a generator sound at 7 meters (23 feet) distance. But in general, there is no industry standard way for testing decibel ratings on portable generators. Many major manufacturers do not even list the decibels of their models. Some provide dB without specifying at what power level they are obtained. All this makes it hard to compare different brands.

Manufacturer
and model
dBA at 1/4 load dBA at 100% load Online price
Yamaha EF2000iS 51.5 61 $926
Hyundai HY2000si - 65 $515
Powerhouse PH2100PRi 56 66 $657
Champion 73536i 53 65 $442
Honda EU2000i 53 59 $990
NOTE: The prices in this chart were gathered before hurricane Irma. In the wake of Irma, Amazon run out of stock on most discount generators, while third part sellers raised the prices.
Generally, inverter generators are the quietest ones among the portables. Most of them are rated between 1000 and 3000 watt. I decided to compare the models in 2000-watt range, which is probably the most popular size for camping. The comparison chart below provides quiet generators data that I was able to gather from the manufacturers websites and/or advertisements. When a link is provided, you can follow it to see the current price and user reviews. The numbers in the chart are given for 1/4 load (when available) and full load. The prices represent the numbers we found online at the time when we compiled this guide.


We can see that Yamaha and Honda portable generators are the quietest. However, they are also among the most expensive models in this category. If you want the quietest device for the money, you may want to consider Champion's 73536i- it is a sufficiently quiet generator at a cost 40-50% lower than best ranking devices. In addition,this model is “stackable”- with a parallel kit two units can be connected and operated in tandem to supply more power.
Note: Generac, Honeywell, Briggs & Stratton, Lifan and some other brands did not publish dB information for this class of gensets at the time of this review. Therefore we can't say if they are louder or quieter than the reviewed models, but I suspect if their noise ratings were superior they would not hide them.