Getting Control Strategies Right is Essential for Efficient Operations

Bill Gnerre, Interval Data Systems
Gregory Cmar, Interval Data Systems

Despite having spent nearly half a billion dollars in construction, and outfitting it with top notch HVAC systems, this research lab wasn't performing as expected. Only three years old, the nine story, 512,000 square foot medical school science and laboratory building wasn't meeting expected efficiency levels. This case study presentation will show the operational analysis that revealed a 70 kBtu/sqft EUI reduction (translating to > $300K/year savings) possible, as well as essential improvements for comfort conditions. More importantly, well discuss how the need for a BAS automation rewrite was identified and implemented.

The building's BAS is interfaced with third-party systems including fume hoods in laboratories and the vivarium, an air quality monitoring system, and a 60-unit fan wall system. The principle HVAC systems include 14 air handling systems supplying over 565,000 CFM, 685 VAV w/reheat terminal units, 404 VAV exhaust terminals with supply tracking, 604 chilled beams, 73 sash-operated hoods, and various fan coils and radiator systems. Hot water, chilled water and electricity is supplied from a central cogeneration plant.

To fine-tune operations approximately 6,000 trends have been captured. A building data model was assembled to define the relationship between equipment and space. The building data model has been used for initial analysis, verification of remediation, and ongoing monitoring. Supplementing the analysis of the operational data was a top to bottom review of 13,000 lines of automation code that confirmed the need for the rewrite. The specification for the new automation was derived from ASHRAE Guideline 36P High Performance Sequences of Operation for HVAC Systems. This foundation has resulted in standardizing control operations along a proven and repeatable methodology for device control and system optimization. Along the way, installation deficiencies were uncovered and corrected to allow the enhancements of the new operating routines.

This presentation will review: initial operational analysis findings, automation code review findings, specification of automation per ASHRAE 36P, automation remediation (the code for the VAV and AHU) and the unplanned remediation work required to get the automation right. Results will be shown in terms of actual airflow reduction by floor and EUI reduction.

Learning Objectives

  • What it takes to get the automation right and why you can't expect good automation from the construction process. The audience will learn the inherent limitations of today's construction process and how it affects the automation.
  • How to use ASHRAE Guideline 36P to evaluate automation and to specify automation. Audience will become familiar with this new guideline and how convenient it is to select Sequences of Operation.
  • Why the remediation process found more work than anyone anticipated. Your project plan may have a well-defined scope but when you fix the automation you're likely to find more automation deficiencies outside of your scope that affect the results you plan to stand behind.
  • You need a lot more data than trend data to evaluate a complex science building. You'll learn the different types of operational data required to operate this type of building efficiently.

Biographies:

Bill Gnerre is CEO and Cofounder of IDS. Bill has overseen IDS' evolution from EEMS software vendor, to analytic services provider, to its current Building Automation Software service offering. He's an owner advocate to ensure customers get the highest quality BAS automation combined with operational consulting via ongoing monitoring. Bill's vision delivers owners the lowest cost of operations in terms of energy and ongoing maintenance while delivering highest level of comfort and safety.

Greg Cmar is CTO and Cofounder of IDS. Greg has architected and developed the EnergyWitness EEMS database and software platform from data collection (BAS, meters, utility) to today's data modeling, fault detection, and diagnostic analytics. He is IDS' operational expert interpreting BAS data as well as specifying SOO per ASHRAE 36P and commissioning automation code. In his remediation role Greg directs control technicians through the process to achieve the automation quality IDS requires.

 

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