In most large generator sets in indoor locations, custom-built Powercity generators with aluminum-encased high-density Fiber Glass Sound Absorber or FGSA are recommended. FGSA offers excellent sound absorption within a wide frequency range and better heat tolerance properties because of its fire-retardant thermosetting resin. The use of FGSA in generator sets is based on several U.S. Patents including –Industrial Noise Abatement Enclosure – Patent No. US4258511A Sound Suppression of Engine Noise – Patent No. US4516657A Acoustically Isolated Enclosure for Dynamoelectric Machine – Patent No. US4007388A

Overloading a generator set for a prolonged period will subject the machine to high thermal stress. The picture on the right shows an overloaded generator running for more than two hours making its turbo and exhaust manifold into a smoldering red-hot metal almost reaching its melting point. In case of fuel or oil leaks that will reach this part, it can cause a fire. FGSA enclosure acoustics are used to mitigate generator fires. There are also areas with local codes requiring fire ratings of rooms and equipment to mitigate the spread of fire.