TAB Journal Spring 2014 - (Page 19)

Chasing the AIR Jeffrey Wicka, TBE, CxA San Diego Air Balance Co., Inc. T esting and balancing was conducted at a 26-story beachside hotel located on the West Coast. Complications arose while attempting to adjust the exhaust in the hotel's restrooms. Numerous exhaust shafts served two restrooms per floor. By traversing the fans on the top floor, a total flow for each shaft could be set, beginning with approximately 120% air flow. In attempting to proportionally balance the air flow in the restrooms, it became clear around midday that there was an increase in grille air on the west side of the building, while the east side decreased. Upon rechecking several floors the following morning, the reverse seemed to be true, with airflow decreased on the west side. The exhaust inlets were proportionally balanced again to correct the issue. Around 11:00 a.m., however, exhaust on the west side was increasing with the east side decreasing. Returning the settings to where they were in the morning didn't seem to help the system proportional balance. What was causing the imbalance? While standing at a window that looked westward to the ocean, it was noticed that air could be felt moving through a ventilation slot on the window. The vent had a manual control, and when the door into the corridor was open, air flow increased. When the corresponding window vent was opened on the east side of the building, it was found that rather than air flowing in, the vent was exhausting air from within the building. Upon checking these vents in the morning, it was found there was no breeze created from the west side. The cause of the imbalance was the ocean breeze, which typically picks up on the West Coast around 11:00 a.m. To further the imbalance created by breezes coming from the ocean, the building was not a standard rectangle shape. It was curved, with the inside of the curve facing the ocean. The mechanical contractor and engineer were informed of the issue regarding the building's proportional balancing. Upon verification that the ocean breeze was the cause of the exhaust imbalance, all the window vents were closed and balancing was completed on the building. TAB Journal Spring 2014 19

Table of Contents for the Digital Edition of TAB Journal Spring 2014

Indirectly Determining Air Volume
Calibration and Balancing of Phoenix Valves in Laboratories
The Trouble with Canned Specs
Environmental Considerations of the Southwest
Airflow Measuring Station Considerations
Putting the Proper "SPIN" on Things
Chasing the Air

TAB Journal Spring 2014