In ventilation, air conditioning and refrigeration applications, designers and operators often discover that the fans installed in their equipment are noisier or less energy-efficient than expected. The conditions of installation are often to blame, as they can have a negative effect on power consumption, air performance and noise emissions. The fan’s impeller, motor, control electronics and housing are optimized for energy efficiency and noise emission, and the actual conditions of installation in AHUs should not be neglected.»