HVAC Contractors Implement Comfort and Efficiency in Schools
Four projects earn high marks when it comes to meeting classroom comfort and efficiency goals
Here is a look at four projects that shine a light on technologies HVAC contractors can implement to help solve comfort and efficiency challenges for school administrators or university boards of directors.
HIGH-EFFICIENCY BOILERS EARN HIGH GRADES
Cornell College in Mount Vernon, Iowa, was founded in 1853. The campus has a long, rich history with some of the original buildings dating back to the 1860s. In fact, the entire campus is listed on the National Register of Historic Places.
Old age is good for aesthetics, but the campus’ aging steam heating system posed many issues and challenges for the facility services department. Installed in the late 1800s, the original steam heating system consisted of a central plant that supplied all the buildings on the university grounds. Originally using coal, the school’s boiler plant was converted to gas in the 1960s when three 350-hp gas-powered steam boilers were installed to provide heat for the entire campus.
Because of the age of the equipment, major repairs to the old steam infrastructure were becoming commonplace. Joel Miller, director of facility services for Cornell College, faced two options — either replace most of the steam piping, or consider another heating solution. The decision was made to move away from the centralized system and install stand-alone high-efficiency boilers in individual campus buildings.
To carry out the project, Cornell turned to Pipe Pro Inc., a Cedar Rapids, Iowa-based company offering commercial and industrial plumbing, heating, and air conditioning services. Travis Godbey, service manager with Pipe Pro, oversaw the boiler upgrades at the school.
One of the first retrofit projects took place at a popular residence facility — Olin Hall. The team installed five Weil-McLain Ultra® 550 MBH high-efficiency condensing gas boilers in the building. The Ultra features boiler-to-boiler communication, Modbus®, and BACnet® for linking with building automation systems (BAS); express setup wizard; 10 preset typical heating systems; and an updated controls interface for simpler navigation, at-a-glance boiler status, diagnostics, and troubleshooting. Three units were configured as the main heating boilers while the other two were set up for domestic water.
The science center building also was selected for a boiler upgrade. Two Weil-McLain SlimFit 750 series boilers were set up as natural gas and installed in the building’s tight mechanical room. According to Weil-McLain, the boilers’ narrow housing enhances maneuverability for confined spaces and weight-restricted areas.
“The SlimFit boiler was a perfect match for the space,” said Godbey.
In total, Pipe Pro completed eight conversions at the campus, all with Weil-McLain boilers. The new boilers are configured to control individual buildings but are also connected through a campus-wide web-based system for monitoring and control.
“I can easily track every unit on campus,” said Miller. “The control system displays boiler parameters from each building on any computer, notepad, or phone, and our team can make adjustments as needed in real time.
“In addition, the boilers are very user friendly, he continued. “They don’t require the highly trained boiler operators needed for the steam plant. We can even conduct the annual maintenance on the units ourselves.”
As anticipated, the change-outs have led to energy savings; the campus has experienced a 15 percent reduction in gas usage after eight conversions.
But, most importantly, Miller reported students and teachers are extremely pleased with the climate of the classrooms and residences.
“My phone does not ring as much since the changeouts,” he said.
DEMAND-BASED VENTILATION SAVINGS ENABLE RESEARCH
In the face of growing energy costs, the University of Cambridge’s Hutchison/MRC Research Centre in Cambridge, England, was faced with the unsettling prospect of reducing life-saving cancer research to pay utility bills.
A leading site for basic and translational cancer research, the Hutchison/MRC Research Centre was built in 2001. It houses about 160 research scientists and support staff from the MRC Cancer Unit and Department of Oncology for the University in 11 laboratory spaces over three floors. The center has about 12,000 square feet of lab space, one floor for support services, and one plant room floor.
Brian Richardson, research center manager for MRC, knew the center presented some inherent challenges. Full air conditioning was required at all times to keep the laboratories operating properly. This meant ventilation systems had to be operating at the same rate day and night whether occupied or vacant. The building was also running at higher than normal air change rates due, in part, to flaws in the building’s original design.
Chris Mulholland, operations director for Critical Airflow Europe, the center’s airflow control system vendor, told Richardson he might have a retrofit solution that could provide energy savings up to 50 percent. The new solution would modify the center’s traditional variable-air -volume (VAV) control in lab spaces with the demand-based Aircuity system, which allows the ventilation to vary based on conditions in each laboratory. Although in place at numerous university laboratories in the U.S., the Aircuity system proposed for the Hutchison/MRC Research Centre would be the first in the U.K.
According to Aircuity, the company’s airside efficiency platform optimizes air change rates based on comprehensive indoor environmental data. Air samples are continuously gathered from individual spaces at the air handler level and routed to a sensor suite for analysis. The sampled data is transmitted to a web-based platform for archiving and reporting. A signal is then sent to the facility’s building management system (BMS) to adjust the ventilation levels based on current conditions, which provides energy savings while improving IAQ.
Critical Airflow proposed to reduce the air changes per hour (ACH) from the existing rate of 24 ACH for both occupied and unoccupied periods to a minimum air change rate of four ACH during the day and two ACH at night.
In the first year, the system reduced total gas costs by approximately 41 percent, and the total electric bill by 9 percent for a combined savings of 67,000 euros (about $85,000). In the second year, total gas costs were down by 54 percent. The system payback was less than two years. In addition, the system reduced carbon emissions by 422 metric tons (tonnes) per year.
“We achieved our main goals of improving the laboratory environment for our occupants, reducing the environmental impact of the research center, and, crucially, reducing our expenditure on utility costs,” Richardson said. “Without this installation, we would have been in the unenviable and inevitable situation of having to reduce direct research budgets to pay our gas bill. But with such impressive financial benefits, the science budget is protected with a directly positive impact on cancer research.”
IAQ TECHNOLOGY SAVES ENERGY, BENEFITS STUDENTS
Poor IAQ has been linked to symptoms such as headaches, dizziness, tiredness, and difficulty concentrating. So how can schools and universities ensure a healthy learning and working environment for their students, faculty, and staff without accruing incremental costs to do so?
One option is enVerid Systems Inc.’s HVAC Load Reduction® (HLR®) technology, which is designed to capture and remove contaminants from indoor air, such as CO2, aldehydes, volatile organic compounds (VOCs), and particulate matter. In addition to improving IAQ, by cleaning and recycling indoor air, the HLR technology enables universities to reduce outside air intake in their buildings, thereby decreasing the load on their HVAC systems. This can lead to significant energy use reduction and cost savings.
The University of Miami recently decided to implement enVerid’s HLR technology in its UHealth Fitness and Wellness Center at the Miller School of Medicine. The school of medicine’s physical plant encompasses about 5.1 million square feet. It is served by a centralized chilled water plant designed for 20,000 ton with 12,000 ton installed at the time of the implementation. The Wellness Center occupies 60,000 square feet on the top two floors of the school.
“Here in Miami, outside air is a huge cost of energy,” said Carl Thomason, energy manager, University of Miami Miller School of Medicine and UHealth Hospital and Clinics. “Humidities are typically above 80 percent, temperatures are around 90 degrees, and every 100 cfm of outside air we bring in equates to about 1 ton of cooling on our chiller system. During the summer, we are constantly at the highest load the plant can handle.”
In addition to the heat and humidity, the school of medicine is subjected to pollutants from its location close to a highway and underneath the airfield flight path of Miami Intl. Airport.
To scrub the air of contaminants and reduce the amount of outside air ventilation required, enVerid HLR Modules were installed on each floor of the Wellness Center.
“With the enVerid system, we’ve gained better indoor air quality with less outside air,” Thomason said. “Our original CO2 levels were usually around 900 parts per million, and, now, with the enVerid system, CO2 levels are around 700 parts per million. VOCs are also down across the board.”
The HLR technology also helped the school achieve a 36-percent average reduction in total HVAC energy consumption and a 41-percent peak HVAC capacity reduction.
Ronald A. Bogue, assistant vice president of facilities, University of Miami Miller School of Medicine and Health System, noted enVerid’s HLR technology adds tonnage to the existing chiller loop by its efficiencies. This could help save the university from having to make a large capital investment in another chiller or cooling tower.
“If you’re running an operation that is maxed out in its plant capacity, this gives you an opportunity to increase the capacity of the system without undergoing major infrastructure changes,” Bogue said.
“We are pleased to provide our innovative technology to support the continued health and productivity of individuals on school campuses around the world,” said Dr. Udi Meirav, CEO, enVerid Systems Inc.
SCHOOL STATS INCREASE CONTROL, SAVE TIME
Located in Southern California, just north of Los Angeles, the Conejo Valley has temperatures that range from below freezing in the winter to well above 100°F in the summer. The Conejo Valley Unified School District is the K–12 school district serving Thousand Oaks, Newbury Park, and Westlake Village. The district has hundreds of thermostats across 30 sites, which include school campuses, offices, and warehouses.
Rick Freed, energy manager and educator for the school district, wanted to be able to remotely monitor, control, and make global changes across the district’s thermostats with the ultimate objective of reducing energy usage and costs. To that end, Freed enlisted the help of Venstar, a manufacturer of thermostats and energy management systems.
Venstar’s SchoolStat thermostats are designed to help schools reduce energy costs while maintaining indoor comfort for students and ease of use for faculty. And, with Venstar’s Skyport Cloud Services, global changes can be made to all of the thermostats at the same time.
According to Venstar, the SchoolStat is compatible with virtually any type of HVAC equipment. Features include a push-to-start button, programmable override, setpoint-limiting security, and separate weekday and weekend programmability. When combined with Venstar’s free Skyport Cloud Services and Skyport Mobile App, energy managers can use the web or their mobile devices to instantly access and control multiple Wi-Fi thermostats from anywhere that has internet access.
Freed said he appreciates the ability to remotely put the Wi-Fi-enabled SchoolStats into unoccupied mode during summer and winter breaks and back into occupied mode for the school year. He also credits the SchoolStat thermostats with saving a considerable amount of energy with their simple push-to-start button. This requires teachers to enable heating or cooling by pushing a button and results in a considerable reduction in energy usage over the previous thermostats, which were set to automatically run the HVAC equipment during all school hours.
The classroom thermostats are pre-programmed with setpoint limits, giving teachers some flexibility of temperature within reasonable limits — in the case of the Conejo school district, +/- 4°F. If there are complaints about classrooms being too hot or too cold, Freed can use Venstar’s Skyport to check the actual room temperatures, allowing him to respond quickly to any potential problems.
Freed reported the school district saved 40 percent on its energy costs in one year, a significant portion of which he attributes to the SchoolStat thermostats. He said the savings are expected to increase exponentially as the district continues to expand the use of its Wi-Fi-enabled SchoolStats along with other energy-saving efforts.
“Venstar’s SchoolStat thermostats have greatly contributed to reducing energy usage for our school district and have made it easier than ever for our teachers to have comfortable classrooms and for our maintenance team to reduce the time it takes to manage the thermostats,” Freed said.
DOE LAUNCHES ZERO-ENERGY SCHOOL ACCELERATOR
The U.S. Department of Energy (DOE) launched the Better Buildings Zero Energy Schools Accelerator. Six school districts, two states, and several national organizations are working collaboratively to develop a zero-energy, cost-effective design in the education sector and in local communities across the nation.
“Through the Better Buildings Zero Energy Schools Accelerator, partners commit to real savings,” said Kathleen Hogan, the DOE’s deputy assistant secretary for energy efficiency. “By using the most energy-efficient technologies and engaging students and the local community, school districts can lead the way in saving taxpayer dollars and creating more resilient and first-in-class educational facilities.”
According to the DOE, zero-energy schools have the potential to save 65-80 percent in energy consumption depending on the climate zone, and the goal of the Zero Energy Schools Accelerator is to quickly make zero-energy K-12 schools more mainstream.
Publication date: 12/25/2017