Indoor Air Mixing Issues
Wheaton Franciscan -The Wisconsin Heart Hospital (Milwaukee, Wisconsin)
Pearson Engineering was retained to solve air mixing issues in the building’s four existing air handling units. Original design and sizing of the mixing box sections created stratification in the airstream, which resulted in continuous freezestat alarms during the heating season. After careful inspection of the air handlers, including temperature and airflow measurements, we relocated air control dampers to the exterior of the air handler. This created a smaller mixing section within the duct work, which increased airstream velocities of the outside air and return air. The increased air velocity created more uniform mixing and eliminated the airflow stratification, thus eliminating the majority of freezestat alarms for maintenance staff.