Tips and tricks for commissioning, balancing buildings: Sustainability, energy efficiency
Building commissioning is one of the most important (and complex) types of projects an engineer can be tasked with. Renewable energy or sustainable systems require specialized expertise.
- Jerry Bauers, National director of commissioning, Sebesta Blomberg, Kansas City, Mo.
- Michael P. Feyler, Co-director, building solutions group, RDK Engineers, Andover, Mass.
- Robert J. Linder, PE, Senior project manager, Karges-Faulconbridge Inc., St. Paul, Minn.
- James Szel, Senior vice president, Syska Hennessy Group, New York City
- Geremy Wolff, Commissioning manager, McKinstry, Bellingham, Wash.
- Barney York, Project manager, RMF Engineering, Baltimore
CSE: What cutting-edge energy efficiency systems have you recently commissioned? What design aspects or products were included?
Szel: A heat recovery chiller harnesses the heat that is otherwise rejected from the chiller and typically released into the atmosphere. The heat recovery chiller recovers the “waste” heat from the chilled water unit and uses that heat for other applications in the building, like humidity control, HVAC reheats, or even potable hot water systems. Being that most buildings have a constant need for hot water regardless of the time of year, the heat recovery chiller can greatly reduce energy bills and a building’s carbon footprint year round.
York: I recently commissioned a 160,000 pounds/hour (PPH) condensing economizer located at a university campus central steam generating plant. The economizer was custom designed to provide a 5% efficiency boost to the overall plant operations, and was only the second installed at a U.S. university campus. The economizer was connected between two 80,000 PPH steam boilers and consisted of two indirect contact heat exchangers, its induction fan, and a direct contract water spray system the plant uses to preheat the combustion air and make-up water.
Wolff: Evaporative cooled data centers with hot aisle containment. We are seeing our customers moving away from the stringent temperature and humidity control requirements used earlier on when these types of structures were first introduced to the marketplace. This allows facility personnel to operate a data center at higher temperatures and use evaporative cooling versus the more expensive mechanical cooling. However, this results in systems that move significantly more air through the space, which introduces other project challenges. This puts additional focus and scrutiny on safety and staging when it comes to the sequence of operation and operating procedures.
CSE: Have you had experiences with photovoltaic (PV), wind turbine, or other renewable energy?
Szel: Yes, we have commissioned solar PV systems. The Solmetric PV analyzer is a good tool for testing IV curve performance and producing IV curve test results.
Wolff: Some, but most have been demonstration projects. We still consider these as “emerging technologies” and have not seen them used on “typical” commercial buildings.
York: Working with PV systems can be tricky. As such, designers and CxAs must pay particular attention to a couple of items. The first is how the panels are wired. Panels are commonly wired in a series fashion, and any break in series will cause the entire system to not operate. Second, panel orientation can also be an issue. For example, panels installed in an east-west pattern can cause the sun to be exposed to only half the panels at any given time, and will prevent the panels from operating at full power as some section will always be shaded. Re-orienting the panels into a north-south configuration can easily resolve the issue.