CPIC - RCMP Headquarters Ottawa

The transformation of this building by the introduction of large scale computing facilities required a significant cooling capacity increase, which included multiple large, roof-top chillers. In order to maximize energy efficiency the chillers were modified to incorporate free cooling with additional coils. This caused additional pressure drop on the air flow which required the replacement of the fans with much higher power fans, which in turn made a large amount of noise, including strong tonal components. This noise travelled across the river, disturbing the residents. Public Works hired three different acoustic consulting firms to fix the problem but no effective solution was found. When they turned to us, we analyzed the problem very carefully via measurement at the chillers and the residential site to determine that the chillers needed to be returned to the original design, the high power fans removed and replaced with lower power ultra-quiet fans. The free cooling coils were removed and the energy saving component was replaced with quiet machines. The result is that we lowered the overall noise level and completely eliminated the tonal component and thus the complaints. The client had not been informed in the original design process that this type of change would result in significantly higher noise levels. In this case, the quest for energy efficiency and an environmental benefit in the mechanical design resulted in the degradation of the environment for the residents. This problem had remained unsolved through years of investigations at all levels of the government and by many consultants until we stepped in with a definitive solution.