- One of the main challenges for generator set manufacturers is developing their designs to provide the quietest solutions possible; capable of complying with local and state standards in any application.
- Dagartech, a company specialised in customised energy solutions, offers generator sets with noise levels below the market average.
The main manufacturers of generator sets have spent decades studying how noise is propagated and developing their designs to make these devices increasingly quiet. Designing more effective and surrounding canopies with sound-absorbent materials that minimise the noise levels of generators continues to be a challenge for the sector.
The reduction of unwanted noise levels in operation is an essential requirement for compliance with local and state regulations, federal regulation and directives issued by the Parliament and Council of the European Union.
The reduction of acceptable noise levels for outdoor machines seeks to protect the health and well-being of citizens, as well as the environment. There are also specific regulations that govern exposure to noise in the workplace, with the premise of protecting the health and safety of employees.
Taking into account that untreated noise levels in a generator set can reach and even exceed 100dB(A), keeping these levels below 70dB(A) is a task that requires work to develop increasingly efficient solutions. But how can we achieve this?
What are the sources of noise in a generator set?
The first step will require ascertaining the sources generating that noise and quantifying it. Thus, in summary, the noise produced by a generator is directly linked with what is produced by its main components:
- Engine noise, and in general, derived from the mechanical forces and the combustion process. Its size and the working frequency will cause variation in sound levels, and can be between 98 and 120 dB(A) at 1m, approximately. The ventilator is another of the components that will negatively affect the device being noisier.
- Alternator noise, produced by the cooling air, friction of the brushes and the fluctuation of the current in the winding. In general, this component will not project noise levels greater than 90 dB(A) at 1m.
- Exhaust noise. This may exceed 120 dB(A) if the generator is not equipped with silencers.
- Other mechanical noises, which mainly come from vibrations of the different components when the device is operating.
How can we reduce the noise of a generator set?
It must be taken into account that the final location where the generator set is installed will affect whether electrical generators without soundproofing (commonly known as open generator sets) or generators with soundproofed canopies are chosen.
In this way, when the device is installed in a room, and it is isolated – that is, not being in direct contact with people – it is common to opt for open generators, while when their installation is outdoors, properly soundproofed machines are chosen.
In any case, different strategies may be followed, through which the noise impact of the generator set is minimised.
Using high quality absorbent materials
Choosing high quality acoustic insulation is a highly effective way to reduce noise levels. Fibreglass or high density polyurethane foam are often used to cover the bodywork of generator sets.
Focusing on connections between components and the levelling of the device
Part of the noise associated with the generator set is due to vibrations of the device. The connection points of components of the generator set (such as supports, ducts, etc.) are susceptible to increasing the noise levels of the generator. Incorporating flexible joints on these connection points or mounting the generator on levelling silentblocks and shock absorbers is another of the options we can carry out to minimise their effects.
Exhaust silencers, key in noise reduction
Generator sets are equipped with different exhaust silencers which limit the noise of this component. They are a key component, and also vary in morphology and composition.
Industrial silencers reduce noise levels by between -10 and -15dB(A). Residential silencers may also be incorporated, increasing this noise reduction by up to -30 or -35 dB(A). High attenuation exhaust silencers increase this noise reduction up to -50dB(A).
The Dagartech Rental Plus range, generator sets with noise levels below the market average
Dagartech has developed a range of generator sets specially designed for use by machinery rental companies. They are generators that are always located in outdoor spaces, and in applications which are especially sensitive to the noise factor, such as events, concerts or use in the field of construction, where the proximity of the machine to employees is inevitable and almost continuous.
The new Rental Plus EU Stage V range has been designed with the objective of rental companies being able to offer a long operating cycle with guarantees, complying with the current directive on emissions, and doing so with the minimum possible noise levels.
Thus, in addition to offering a high quality product with extensive features, this range is notable for having noise levels below the market average. This is largely due to the interior soundproofing of the devices, with treatment of the engine noise (mechanical forces and combustion), ventilator, mechanical noise of the alternator, induction noise, exhaust and other structural noises.
Additionally, the Rental Plus generators can include a high attenuation kit with which the noise levels of the machine are reduced by between 2 and 3 dB(A) more.
The standard range of features is complemented, among other attributes, by an electro-welded high resistance galvanised steel canopy, painted with epoxy-polyester powder based electrostatic paint and tested in a saline mist chamber in accordance with standard ASTM B-117-09 (resistance of 720 hours). The canopy is certified for C4H and C5M-M under testing conditions in accordance with standard UNE-EN-ISO 6270 in condensation test and UNE-EN-ISO 9227 in corrosion resistance test. Additionally, it passes the ISO 4628 tests on blistering, oxidation, cracking and flaking.
The devices also include a mechanised cable grommet at the output terminals of the generator switch and a large capacity metallic tank with liquid retention bath, located on the bench itself. Records of cleaning considerably facilitate maintenance work and cleaning of the tank (the engine manufacturers recommend cleaning or checking the water and residue levels in fuel tanks every 2 months). Additionally, its control switchboard with free software (which offers the user autonomy and independence from the manufacturer) is able to record up to 250 events, which allows recording of stoppage or alarms in the field, and thus better diagnosis of breakdowns on site.
About Dagartech
Dagartech is a Spanish company specialised in offering customised energy solutions. In this way, the company 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.
Dagartech generator sets are always developed considering the target application, the machine’s circumstances of use, the latest advances of the power generation market and the demands of clients. Therefore, 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.
The company has committed to innovation and has built up a human team with extensive experience in the energy generation sector. 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.
