Usually, we buy generators for two reasons; as a backup power source in the case there is a power interruption or for outdoor events. They significantly improve our lives. But there is one problem: they are noisy! They may disrupt your sleep and annoy your neighbors. Portable generators have an average noise level of between 60 to 90 decibels measured at 23 feet.
Fortunately, technology is advancing, and we have seen various improvements in terms of noise produced by the generators. A generator usually generates noise from six components namely; engine noise, alternator noise, cooling fan noise, inductive noise, engine exhaust, and structural or mechanical noise.
Various manufacturers have made efforts to reduce the different noises produced by generator components to minimize noise pollution and meet the limit set by the World Health Organization which is 70 dB. But what makes other portable generators to be quieter than others? Below are some of the reasons.
1. Engine Type
Generators with gasoline engines tend to be quieter than generators with diesel engines. The main difference is how fuel is burnt to generate energy. Gasoline engines have spark plugs that instigate combustion whereas, in diesel engines, fuel is ignited by compression with no other external sources to trigger burning — thus making combustion in diesel engines more spontaneous and violent, producing more vibrations and harshness making diesel engines to be noisy.
2. Exhaust Mufflers
Most generators come with inbuilt exhaust mufflers (silencers). Mufflers come in a wide range of classes, material, and physical arrangements. They are made from stainless steel or cold-rolled steel each suitable for particular conditions. Mufflers are generally meant to reduce the noise that is generated by the generator’s engine exhaust.
3. Isolation Mounts
Mounts are placed around a portable generator to help in reducing noise levels. Vibrations produced by generators are a source of noise and efforts to minimize vibrations lead to an overall reduction in noise levels. Isolation mounts and flexible connections in most generators significantly reduce vibrations and noise as thus quieter than those without mounts.
4. Air Movement
A running generator creates a lot of air movement. This movement of air creates noise. Air routing paths along with placement of baffles are some of the improvements made to help in reducing the high-frequency level of noise originating from this air movement.
5. Type of Portable Generator
Inverter generators are designed to be amazingly quiet. They come with special mufflers, silent engines and sound-dampening technology is used to keep the noise level down. They maintain a constant flow of current while using some advanced technology hence significantly reducing the noise level.
Silenced portable generators, on the other hand, come fully enclosed in a unique soundproof cabinet known as the acoustic cabinet. They generate lesser noise compared to conventional generators. The inverter generators are however quietest of them all.
Manufacture of less noisy generators is on the rise, and we expect quieter generators in the coming future. Larger generator engines that produce more power strokes per revolution (RPM) also tend to be noisier than those that generate fewer RPM.