Facilities (Learning Spaces)
Creating Intelligent Schools
- By Ellen Kollie
- December 1st, 2014
PHOTO COURTESY OF TRANE
Today's proven energy-efficient technologies, along with new technologies, can transform the energy footprint of the built environment and lay the foundation for a sustainable energy future. But before we can look at today or the future, we have to understand the past.
Energy management: The past
“In the 1960s, HVAC and lighting equipment was manually enabled and turned off and on using thermostatic control,” says Bruce E. Beddow, PE, CEM, president of b2E Consulting Engineers in Leesburg, Va., which offers such services as building automation and controls, building technology and energy audit/analysis. “That’s all there was to it. “In the 1970s and ‘80s, we developed comfort control, and we weren’t overly concerned with energy consumption,” Beddow continues. “Since the beginning of this century, with LEED and other benchmarking tools in play, school administrators have been looking at evaluating their buildings to try to save energy because it’s starting to get expensive.”
And, oh my, the strides that have been made.
Today’s energy-efficient technologies
Today, schools’ energy usage is managed by Building Automation Systems (BAS) that are extremely capable. “The sky is the limit regarding how many bells and whistles you want to design into them,” says Beddow. “Do not get too excited with so much control software technology at hand, just provide the simplest and easiest sequence that uses the essential control points. Every field control point is wired back to the controller where it is continuously monitored. For example, if you want to command a pump on, then read current flowing to the motor to verify ‘run’ status, it’s wired to the BAS. If you want to control temperature and humidity in a space, the control sequence is designed to perform that function. The control software sends the commands, and the system responds automatically. If you want to increase the ventilation in a theatre or assembly area when carbon dioxide levels in the space increase above recommended limits, the system responds and opens the ventilation dampers automatically. We have schools that heat/cool/dehumidify and ventilate based on occupancy automatically. The EMS system measures the indoor and outdoor conditions continuously and decides when to provide heating, cooling, dehumidification and ventilation (outside air). Variable speed energy recovery unit technology allows us to use the waste heat of compression to dehumidify and reheat the air to neutral conditions for delivery into the space. We can also switch off the ventilation to a space when it is unoccupied. We can read the airflow rate of fresh air to each space with pressure independent control using shut-off air terminal units (VAV Boxes). We can now read the airflow at each fan automatically read the air balance instantaneously.”
Examples: BAS provide for building occupant comfort. But they also allow for numerous kinds of energy efficiency benefits. “For example,” says Beddow, “we’re asking if we need to run systems all day. Can we program the ventilation to turn off at 3 p.m. and still keep a few remaining occupants comfortable until 6 p.m.?”
Beddow offers another example: “We have completed a project that includes a chilled water system whose first stage is a heat pump, so it makes hot and chilled water at the same time. When there is enough heat created on the air side, it dumps the excess heat into an indoor swimming pool. You can’t do this without the building automation technology. One person would go crazy looking at and adjusting the system every 15 minutes. But the controls can do it and make appropriate adjustments as necessary, while potentially saving the owner tens of thousands of dollars annually.”
And a third example: Let’s say the boiler makes 180°F water. The building temperature is 70°F. That is a temperature difference of 110°F. “All that excess heat is trying to get out of the pipes,” says Beddow. “If you use the BAS to set the water temperature much lower, like 130°F, there is less difference between water and building temperature and, therefore, less heat loss and less wasted energy. In addition, low temperature distribution systems also let you reject any waste heat from a process into the low temperature loop more easily, which expands the possibilities for waste heat recovery.”
With BAS, energy efficiency goes even farther than the above examples. For instance, other systems, such as solar thermal, can be connected to BAS to create options for using heat recovery technology. Beddow explains: “Some schools run their boilers half an hour every day in summer so building occupants are not overcooled. That seems absurd, especially because it wastes energy, yet administrators don’t want complaints about comfort. So we’ve tied domestic hot water heat solar systems to the boiler systems, moving the heat from the solar collectors at 135°F into the boiler loop at 120°F and heating the boiler water with renewable energy. You couldn’t do that without an BAS because there’s a sequence of events that have to be controlled to make it happen.”
“When you incorporate energy-efficient technology, turn things off that don’t need to be running, reduce/increase temperature when no one’s in the building, shut down air ventilation when space is not being used, and use waste heat from a high temperature process into a low temperature process whenever possible, it all saves energy,” Beddow sums.
Programming: BAS are programmed to optimize energy efficiency and maintain certain levels of comfort in buildings, and it’s all automated. When it comes to programming BAS, it’s important that the engineer design an efficient building and control it via a simple program that works reliably no matter the time of year.
“There’s a whole thought process on controls and how to write them,” Beddow says. “Some sequences are convoluted and confusing. Others are concise, have fewer variables and are more accurate. Ultimately, when writing the software, it’s important to use simple terms and keep things short. A good control sequence allows you to do complex functions easily and reliably without a lot of complications. Once the sequences are correct, as verified by commissioning, they will work reliably indefinitely.”
Where there’s power: Another powerful technology that has started to enter the marketplace is a Building Energy Management Systems (BEMS). “A BEMS system typically overlays a BAS and has the ability to help administrators visualize energy spent and find opportunities to improve energy spend,” says Matt Gates, LEED-AP, director for Intelligent Services Offerings for Trane, a leading global provider of indoor comfort solutions and services and a brand of Ingersoll Rand. “Sometimes that comes in the form of just a technology tool but usually it’s a combination of a tool and a consulting person who says, ‘What if you did this to change how you use energy?’”
Benchmarking: For administrators who want to use their BEMS to reduce energy consumption, Gates recommends starting with determining the normal baseline of usage for each school, which can then be benchmarked against one another and against schools in other districts. Then energy consumption can be reduced through such measures as bringing a school back into compliance by tweaking settings, upgrading equipment and changing behavior (reminding staff to turn off lights).
There’s more: Gates suggests that administrators, even if they have intelligent schools, continue to explore energy efficiency, pointing out several considerations. “Anytime a school district does any project,” he notes, “officials should consider some level of measurement and verification. The International Performance Measurement and Verification Protocol (IPMVP) can be used by anyone to interpret the data when measuring energy or water savings. It’s a way to be aware of savings and a way to approach measurement and verification once a project is complete.” He also recommends an understanding of performance contracting, which a lot of districts use to develop energy efficient schools. “Even in a nonguaranteed project,” he observes, “understanding the benefits is useful.” Lastly, he suggests an understanding of supply and utility schedules and tariffs: “A relationship with your local utility company allows you to understand what those schedules are.” He notes that — especially as districts grow — needs change, so it’s important to have someone whose job it is to think about schedules and tariffs, so they can be adjusted as necessary to the greatest benefit.
The future of intelligent schools
With all this technology and capability, it’s hard to imagine that the ability to create intelligent schools could get any better. And yet, it will. In fact, it is, thanks to cloud technology.
“Schools are becoming more advanced, and administrators are really starting to leverage cloud technologies in order to schedule, report data, see real-time energy usage and more,” says Jamie Sitter, K-12 marketing manager at Siemens Industry, Inc., specializing in electronics and electrical engineering throughout the United States. “This is allowing them to use data to make more informed decisions, and also helping to combat many lingering issues such as understaffed districts, tight budgets and deferred maintenance.” Some specific items that cloud technology addresses include streamlined scheduling, preventive maintenance, personnel configuration, heating/cooling limits and asset management.
What’s more, cloud technology assists administrators in their efforts toward sustainability in that, through the use of data pulled from the cloud, they’re able to make more informed and appropriate decisions. They can be notified immediately of a problem with the network or infrastructure, which allows for anytime, anywhere management. “This all leads to a big push on the sustainability front because administrators can see how the building is operating, set limits to heating/cooling temps, have their equipment serviced on a regular basis to ensure it is functioning to its full potential and also to prevent system failures,” says Sitter. “Through the years administrators have struggled with budget cuts, which have led to increased deferred maintenance and a ‘run to fail’ strategy with building technologies/equipment. Ultimately, the use of cloud technologies will give them the best insight on how their buildings are functioning, which can lead to long-term planning and budgeting, preventive maintenance and so much more.”
In addition, cloud technologies assist administrators in their efforts to reduce energy consumption by providing the insight needed to help them understand how their schools are performing (in real time), make on-the-spot system adjustments to fix issues at off-hours and more. “Rather than letting schools run at off-hours, administrators can schedule the lighting, heating and cooling, saving kilowatt hours and, therefore, saving money,” Sitter says.
Sitter believes the future of intelligent schools will revolve around cloud usage and customization of each district’s needs via streamlined cloud offerings/technology. “It will also be crucial that administrators partner with companies that specialize in building technology and infrastructure to allow guidance and a trusted, open communication line about new trends and technologies,” she indicates. “The value of this is to have an industry expert who knows the district’s schools and can offer advice to further advance sustainability.”
While the ability to create intelligent schools has come a long way and has a bright future thanks to systems, tools and technology to help administrators manage energy, none of it replaces the need (such as BAS and BEMS) to perform traditional maintenance. “Preventive maintenance needs to happen,” says Gates, “to help administrators maximize the lifecycles of the systems that are in place. When decisions are for deferred maintenance, it doesn’t matter how well you use the tools or change behaviors, you can’t make the equipment run better.”
This article originally appeared in the December 2014 issue of School Planning & Management.