The Next Step in Cutting Utility Costs
Now comes commissioning, a process that maintains the efficiency of the various parts of an integrated building automation system (BAS) by monitoring each system and constantly scanning for problems. Automated building system controls, integrated into a single system and then properly commissioned have cut utility costs in some buildings by an astonishing 30 to 70 percent.
The digital revolution has made buildings all across college and university campuses more comfortable and less expensive to heat, cool, and light.
“The arrival of PC technology made it possible to automate building systems,” says Carlos Petty, vice president and group manager with the New York City-based Syska Hennessy Group. “Thanks to the Internet, we can integrate or tie these automated building systems together and control them from one central point.”
Now comes commissioning, a process that maintains the efficiency of the various parts of an integrated building automation system (BAS) by monitoring each system and constantly scanning for problems.
Automated building system controls, integrated into a single system and then properly commissioned have cut utility costs in some buildings by an astonishing 30 to 70 percent.
Start With Automation
Automated systems today can control the operation of most building systems. New state-of-the-art programmable thermostats can maintain building temperatures created by heating, ventilating, and air-conditioning systems. Dimmers, occupancy sensors, and other controls can maximize the use of natural light while minimizing the power used for electrical lighting. Fire and life safety systems use sensors to detect smoke and heat.
Audio-visual window shades can be set to darken the room when a digital video projector clicks on. Security technology can automatically lock and unlock doors and operate video cameras. Controls can even operate digital signage that provides information about who is scheduled to use various rooms.
Integrating Building Controls
In addition, engineers are integrating many of today’s building automation systems (BASs), making it possible to coordinate and control the use of energy and water more precisely using a laptop and a browser.
“An integrated BAS uses advanced methods to communicate with disparate systems,” says Petty. “For instance, a system might use open communication control protocols such as BACnet (the Building Automation and Control network open protocol communication standard developed by ASHRAE).”
“Another approach to integration is to use one automation system provider that installs their own proprietary (instead of open) controls on all of the equipment and ties everything into their front end system,” says Tim Lehman, mechanical discipline director with Celina, OH-based Fanning Howey, an architectural firm specializing in educational design. “That’s how Siemens and Johnson Controls integrate building systems.”
Integration makes it easier to use the building controls to keep the indoor environment comfortable. It also makes it easier to confuse the systems and get everything out of whack.
Suppose a professor calls the campus facilities office to complain that it is too warm in the lecture hall where she is holding today’s classes. The technician who takes the call logs on to the BAS system and sets the heat in that hall down from 75°F to 72°F. The professor doesn’t complain anymore, and the technician forgets about it.
The technician has just raised the possibility of wasting hundreds or maybe thousands of dollars in energy costs.
As a technician, he knew that the heating and cooling systems in that building each have a degree set point and two degree control points. He knew that the cooling system has a set point of 70°F and control points of 68°F and 72°F. When the temperature rises to 72°F, the air conditioning comes on.
He also knew that the heating system has two degree control points and used to have a 75°F set point. So when the temperature drops to 73°F, the heat comes on.
But he changed the nicely functioning system when he changed the set point for the heat to 72°F. Now when the temperature goes down to 72°F, the heat goes on. And so does the air conditioning.
It’s okay to make a temporary change, but you must remember to change it back. Now, for the next couple of weeks or maybe months — until someone notices — the heat and air conditioning will run simultaneously, raising utility costs.
Commissioning to the Rescue
While commissioning is relatively new to colleges and universities, one of the seminal studies of commissioning proved the concept’s value using a portfolio of 24 buildings throughout the University of California and California State University systems.
Conducted by the Lawrence Berkeley National Laboratory in Berkeley, CA, “Monitoring-Based Commissioning: Benchmarking Analysis of 24 UC/CSU/IOU Projects” was published in June of 2009.
The study’s authors define the concept and the goal of the study in this way: Commissioning is “a ‘soft’ process of verifying performance and design intent and correcting deficiencies. Through an evaluation of a series of field projects, this report explores the efficacy of an emerging refinement of this practice known as monitoring-based commissioning (MBCx).”
For the study, technicians connected sensors to the building systems in all 24 buildings and sent performance data back to a central monitoring point. By monitoring the data and looking for changes that might indicate a problem, they identified 1,120 deficiencies and developed what they called “interventions” to correct the deficiencies.
During the course of the study, 65 percent of the HVAC systems developed deficiencies — the highest percentage in the study. Air handling and distribution developed deficiencies half of the buildings in the study, followed by cooling plants (29 percent), heating plants (24 percent), and terminal units (24 percent).
By finding and correcting these deficiencies as soon as they developed, instead of waiting for a scheduled maintenance visit, the technicians cut utility costs substantially. In fact, the study found enough savings to pay back the $2.9M cost of building the monitor-based commissioning infrastructure for all 24 buildings in 30 months. After the payback period, a school can put the savings into the classroom.
Out of the Lab, Into the Field
Today, firms provide MBCx as a service, monitoring building systems, identifying deficiencies, and advising owners how to correct the problems.
“We generate weekly reports for clients about building system performance,” says Jay Enck, co-founder and chief technical officer with Commissioning and Green Building Solutions (CxGBS), Inc., a Duluth, GA-based firm that specializes in MBCx and other sustainable building solutions.
CxGBS has been providing these services for 10 years now. Not long ago, the company began offering MBCx services to educational institutions.
“Colleges and universities have only just started to get into monitoring-based commissioning,” continues Enck. “It isn’t widely used by colleges and universities yet, but there are several early adopters.”
One CxGBS university client has 63 buildings. “We collect over four million pieces of data per day for that client,” says Enck. “We analyze the data and report on operational issues.”
Enck also says that MBCx services should include data analysis, noting that some users collect and store data but haven’t begun to analyze and use it.
Clients that use data provided by CxGBS have found substantial savings. “On the high end, we’ve gotten utility cost reductions of 60 to 70 percent,” Enck says. “The average is 30 percent.”
There’s more. “Energy savings is a relatively small portion of the benefits of MBCx,” continues Enck. “It enables you to use human resources — labor — more efficiently. Your technicians won’t have to go to the site to figure out what is wrong, go back to the shop to get parts and then return to the jobsite.
“It also enables reliability-centered maintenance (RCM). Certain kinds of data can warn of potential equipment failure and enable you to prevent a failure with maintenance or new equipment.”
Still more to come: As utility providers upgrade to a smart grid, MBCx data will enable facility directors to program automatic triggers based on usage and the weather to cut systems back during peak hours. “It will take a few years to get there,” Enck says. “But that’s where MBCx is going.”
Source: CP&M , November 2012
Copyright 2013, Peter Li, Inc. All rights reserved. This article is protected by United States copyright and other intellectual property laws and may not be reproduced, rewritten, distributed, redisseminated, transmitted, displayed, published or broadcast, directly or indirectly, in any medium without the prior written permission of Peter Li, Inc.