- Generator sets are an essential solution for guaranteeing electricity supply in emergency situations, or in places where there is no access to the electrical grid.
- The location of generators in environments where they come into direct contact with people requires compliance with the limitations on noise required by the regulations and directives of each country.
While attending a classical music concert or listening to birdsong outdoors may be a pleasant experience, in truth, not all noises are as pleasant, decibels aside. Thus, while sound is everything perceived by our ears, noise may be defined as the unwanted sound that we perceive.
The very nature of generator sets is linked with the presence of noise and vibrations when they are operating, whether continuously or as an emergency power source. Due to this inevitable circumstance, it is essential to understand the sources of noise of the generator, how it is propagated, and of course, to study the best way to reduce it.
As is to be expected, there are regulations that establish limits on the noise that generators can emit, in order to guarantee the health and safety of people who come into contact with them.
Thus, while int he United States there are different ordinances on noise at a municipal and state level, in Europe we are affected by Directive 2005/88/EC of the 14th of December 2005, modifying Directive 2000/14/EC on the approximation of legislation of Member States on sound emissions in the environment, due to outdoor machines, which applies to generator sets.
Where does the noise come from in a generator set?
There are different sources of noise in a generator, and although it is difficult to draw a line separating each one, we can at least establish five main categories:
- Noise from the engine: varying depending on its power, noise from the engine is attributable to the mechanical forces present in it and the combustion process itself, although one of the key elements in noise generation is the action of the ventilator, necessary for dissipating heat and moving large masses of air at high speed.
- Noise from the exhaust: to reduce this, exhaust silencers are used, usually with attenuation levels of between -10 and -15dB(A) in open devices and -25 to 50dB(A) in soundproofed generators, depending on the acoustic needs of the machine.
- Noise from the alternator: particularly important in alternators with brushes when the cooling air passes through them. Of course, fluctuations of intensity of the current in the winding of the alternator also cause mechanical noise.
- Mechanical noise: this is noise arising from the vibrations of the generator set operating and the interaction of its components.
Canopies and noise in generator sets: their function and characteristics
In a previous article we told you how to reduce vibrations in generator sets and mainly focused on explaining the types and locations of anti-vibration elements.
On this occasion, we wanted to focus our attention on the soundproofed surrounds of the generator sets and their main characteristics.
Soundproofed canopies are structures that are attached to the bench of the generator and which have insulation material covering them on the interior. Â Specifically, our canopies are manufactured from high resistance galvanised steel.
Beyond the materials, the architecture of the canopies itself promotes (or prevents) the presence of more or less noise. In this sense, we must understand that an important challenge lies in ensuring that the air inlets and outlets promote the circulation of air inside the canopy, while reducing the output of noise. Having an intelligent canopy design will allow us to fulfil these two fundamental requirements.
Acoustic insulation materials
Driving the flow of air toward walls covered with noise insulation material will certainly be effective. With regard to insulation materials, we can find different options depending on the range and features of the generator. In this way, the canopies of our Emergency Balance Range have polyurethane foam insulation with an outer covering; the canopies of our industrial range are equipped with rigid panels made of fibreglass with an outer textile covering.
How much noise does a generator set generate?
Dagartech, specialists in the manufacture of super-soundproofed generator sets
Dagartech is a Spanish company specialised in offering customised energy solutions. It stands out for promoting unique projects that demand the maximum level of customisation, as well as designing, manufacturing and commercialising a large number of standard generator set products with powers ranging from 3 kVA to 2,000 kVA. With a clear orientation toward the needs of our clients, Dagartech has established itself as one of the main manufacturers of the Spanish market. The company currently has a stable presence in over 30 countries, with exports making up the main volume of its business. Quality and excellence form part of its present and pave the way for its future, which involves the company being certified on compliance with the requirements of the ISO 9001:2015 standard.
