Design tips Follow these design and troubleshooting tips when specifying air handling units (AHUs). · When beginning a project, spend the time to list all the various goals and constraints including proposal requirements, applicable codes and standards, energy goals, and owner preferences. Many facilities require a clear space for service equal to the width of the AHU. · Never skimp on commissioning an AHU. REFERENCES Air Movement Control Association, AMCA Standard 205-2010 (Rev. 2011): Energy Efficiency Classification for Fans. 2012 International Green Construction Code. Because the best way to reduce fan sound is to reduce the fan power, efficient fans frequently have the best acoustic performance.
Evan Riley has more than 10 years experience in design, commissioning, and modeling of HVAC systems. <- Back to: Home. Types of AHUs Fan coils/blower coils are the smallest and simplest category of AHU and, as the names imply, they typically consist of little more than a fan and a heat transfer coil(s). To keep the coils from getting dirty too quickly, a simple filter is also included. The air conditioning process removes water from the air, which is then typically sent to a drain. For many climates, the toughest part of an AHU’s job is treating outdoor air.
Energy recovery is increasingly applied in AHUs and may be required by energy codes in certain applications having high percentages of outdoor air. The more difficult it is to reach a component, the less likely maintenance will be performed, which will result in lower overall efficiency and reduced longevity. This arrangement allows fan heat: which can be significant—to be removed from the airstream without having to subcool the supply air as is necessary for draw-through units.