Noise control on computer and business equipment using speed controlled blowers

The authors present a method to reduce the noise level of computer and business equipment by the implementation of temperature-controlled variable-speed blowers. The possibility for reducing the noise emission is given by the fact that today's cooling design is mostly based on worst-case environmental conditions (maximum temperature and altitude above sea level) to cover the wide variety of the products' worldwide installations. The potential acoustical benefits of adaptive cooling are significant and would be extremely expensive to attain using conventional path noise-control methods such as mufflers or enclosures. However, it should not be overlooked that the price paid for lower noise levels, in addition to the cost of the controller (which is in most cases balanced by the removal of acoustical treatments), is a possible effect on the reliability of the electronics, since their cooling is no longer overdesigned.<>