North Beach School District, Washington

Systems Commissioned:  Project included Cx of 2-Pipe Variable Speed AHU's having separate supply and return fans, electric furnaces, split system Dx cooling air handler, hydronic pumps, general exhaust fans, and kitchen hood exhaust fans.  BAS control system included Honeywell Automated Control System.

In addition to electrical and mechanical systems, our scope of work also included the testing and verification of the fire alarm system and its ability to shut down HVAC equipment upon activation.  The commissioning for Ocean Shores Elementary School noted any deviancies in system operation and enforced system compliance.  MENG Analysis retained our core team through each phase of our work (i.e. value analysis, constructability review, and commissioning) on this project, giving us the leverage, the familiarity and the understanding of design decisions, operational and performance goals for all systems.  Taking advantage of our strong relationship with BJSS-Duarte Bryant, we created a highly effective approach to commissioning and ensured that the building systems operated according to the architectural and mechanical design specifications.  Key issues included:

  • We noticed during commissioning that classrooms 120 and 141 had very noisy return air grilles.  Based on experience of similar probles, branch dampers installed further up the ductwork restricted airflow, thus eliminating the noise.
  • There was no economizer lock-out specified on the sequence of operations, so the control contractor has not programmed one.  For energy conservation purposes, the economizer cycle should be locked out below approximately 58 degrees fahrenheit outsie air temperature.  With no economizer lock-out this control sequence used a lot of extra energy.
  • The bracket supporting the OSA actuator on HVAC-24 was flexing and not driving the damper to full close position.  This actuator was still 10% open when commanded closed.
  • The return damper linkage on HVAC-16 had been installed in such a way that left no room for the actuator to operate.
 
©2017 Meng Analysis