About University of Miami
A private research university with more than 16,000 students from around the world, the University of Miami is a vibrant and diverse academic community focused on teaching and learning, the discovery of new knowledge, and service to the South Florida region and beyond.
The University comprises eleven schools and colleges serving undergraduate and graduate students in more than 180 majors and programs. In 2016, U.S. News & World Reportranked University of Miami No. 44 among the top national universities in the country in its “Best Colleges” listings. U.S. Newsalso cites several of its programs in “America’s Best Graduate Schools.
University of Miami is committed to safeguarding the environment, and in 2005 created the “Green U” initiative to become a community leader in the acquisition of environmentally responsible products and the practice of ecologically sound maintenance and operations procedures.
The indoor air quality (IAQ) was not at the level the facilities management team desired. Fitness centers generate a lot of carbon dioxide (CO 2 ) from people exercising, and the equipment and mats can off-gas formaldehyde and volatile organic compounds (VOCs). Using increased outside air ventilation to improve the air quality inside was attempted, but it made it difficult for the HVAC systems to maintain a comfortable indoor temperature and humidity. Further, the energy
consumption of the HVAC equipment was already quite high and adding more hot, humid outside air ventilation would cause a significant increase in utility costs. Finally, increased outside air ventilation would result in an increase in fine particulate matter coming from the neighboring highway.
Located at the University of Miami Miller School of Medicine in downtown Miami, this 13-story building (figure 1) opened in October 2006. The UHealth Fitness and Wellness Center occupies the top two stories and spans 60,000 ft2 .
The facility (figure 2) includes a 15,000 ft 2 fitness floor with over 100 pieces of state-of-the-art cardio and strength equipment, four group fitness instructional classrooms including a dedicated studio cycling room, and Central Table Restaurant which serves fresh and healthy cuisine daily.
The building is connected to the neighboring clinical research building by a walkway on the 12 th floor. The first 11 stories of the building are a parking facility and were therefore out of scope for this project.
Air quality is an important aspect of health and was therefore a priority to the Wellness Center. In addition, the university has a strong commitment to the environment and energy efficiency is a priority.
The center is served by four air handling units (AHUs) and a pool dehumidification system. The AHUs are connected to a central chilled water system that serves the medical campus. The scope of this HVAC Load Reduction (HLR ® ) installation excluded AHU-1 and the pool area since this area requires special handling and is served by a separate AHU.
In June 2015, enVerid and Johnson Controls installed three of enVerid’s HLR modules in the mechanical rooms serving the Wellness Center.
The project was led by enVerid Systems along with three facilities management leaders from the university: Ron Bogue, Vice President for Facilities and Services, and his staff including, Marcelo Bezos, Director of Energy Management Systems, and Carl Thomason, Energy Manager. In addition, the National Renewable Energy Lab (NREL) was contracted to perform independent measurement and verification (M&V) of energy savings and indoor air quality (IAQ).
Before shipping the HLR modules, the enVerid project team assessed the HVA
mechanical environments, provided a detailed installation plan and obtained necessary permits. They developed an energy metering and monitoring plan, and collected and analyzed air samples for baseline indoor air quality.
In the installation phase, the enVerid project team selected and supervised electrical and mechanical subcontractors with the customer’s approval. Installation was completed with no disruption in HVAC service to building occupants.
Installation included wireless Internet connectivity to feed air quality data into the enVerid Internet-of-Things (IoT) cloud-based platform for 24/7 monitoring. Each HLR module underwent its own acceptance test, and final acceptance tests for the building were completed after all modules were tested individually. Finally, an air test and balance was conducted by a third party, Air Balance and Diagnostic Company, to measure and adjust the outside air delivered to each zone.
The three HLR modules went live on July 2015. Each HLR module includes enVerid-developed synthetic sorbents housed in cartridges that adsorb CO 2 , formaldehyde and VOCs. The HLR module also has a set of sensors measuring temperature, relative humidity, CO 2 and VOCs. The HLR system interprets the output of these sensors using control algorithms to actively and automatically manage indoor air quality and outside air volumes.
The Energy and Air Quality Measurement Methods
The National Renewable Energy Lab (NREL) validated and confirmed the energy savings of the HLR system. Energy consumption of the HVAC system was measured, day by day, to compare days with the HLR module operating versus when the HLR was off.
Measurements were taken on July 11, 2015 and were completed on September 5,
2015. In order to further confirm the savings, energy consumption was measured again in 2016, this time starting on August 14 th until September 21 st , and then again in 2017 from June 6 th until September 27 th . Energy consumption was measured using an energy meter installed by the building facility management. Chilled water consumption and outdoor conditions were also monitored.
Without HLR modules, ventilation rates were set according to the Ventilation Rate Procedure (VRP; ASHRAE Standard 62.1-2013). When the HLR system was in use, outside air volume was reduced by 75% based on the Indoor Air Quality Procedure (IAQP; ASHRAE Standard 62.1-2013).
For indoor air quality, contaminant concentrations were measured prior to the HLR module operation, then again after the HLR technology had been installed and running for at least one week. Indoor air quality monitoring was performed per EPA Standards and the results were analyzed by a third party certified lab (Prism Analytical Technologies).
This investigation included environmental and indoor air quality sampling of temperature, relative humidity, CO 2 , speciated (separated by species) volatile organic compounds (VOCs) and total VOCs (TVOC), formaldehyde, and particulate matter with aerodynamic size of less than 2.5 μm (PM2.5 ). These include all the contaminants of concern typically found in buildings. The investigation included sampling at six different locations in the center. To prevent instrumentation-based discrepancies, we tracked the instruments used for each type of measurement, along with the manufacturer reported detection principle, resolution, and uncertainty.
The HLR system realized 36% energy savings while improving the air quality in the space.
Peak HVAC Capacity Reduction: 58 tons
Peak HVAC capacity is calculated to be 58 tons lower (19 tons saved per HLR module), which corresponds to roughly a 41% decrease in peak HVAC load. This savings impacts the “demand charges” on their utility bill, which in many locations, has a major impact on the overall cost of electricity. In addition, when the Wellness Center replaces the HVAC equipment in the future, the peak capacity required will be 41% less, providing significant capital expense savings.
The measured peak load reduction was lower than 58 tons, which was due to two factors:
- The indoor temperature and relative humidity were not kept constant, as explained in figure 6.
- The chiller set-points and parameters, were not yet optimized for HLR operation, so energy consumption would spike and trough in a cyclical manner. These unnecessary spikes lower the realized reduction in peak load.
Reduced Water Consumption: $9,200/year
University of Miami uses a central chiller plant, so specific water savings for the Wellness Center is difficult to confirm, but are calculated to be $9,200 annually based on the cooling load and annual cooling hours
Energy Savings: 36%
Using the HLR modules, the University of Miami’s Wellness Center is now using 75% less outside air and saving 988 Ton-hrs per day of cooling – a 36% reduction in total HVAC energy consumption. As a result, the building is saving $19,500 each year in energy consumption.
The individual daily measurements and corresponding outdoor enthalpy is shown in Figure 5. By decreasing unnecessary exhaust, savings increased to 36% in 2017.
The energy savings would have been higher if indoor temperature and humidity inside the building were kept constant with and without HLR technology. In Figure 6, the indoor temperature and humidity are charted for when HLR technology was On and Off. When the HLR system is Off, indoor humidity is 10% higher, and temperature also was a couple degrees higher. This condition was observed consistently during the measurement and verification period.
- Filters: A 75% reduction in outdoor air can double the lifetime of the outside air filters. Given that the UHealth Fitness and Wellness Center is next to a major highway, reduced filter changes can save hundreds of dollars each year.
- Reduced Corrosion: A reduction of outdoor air intake reduces the introduction of saline latent outside air, providing several secondary benefits that include extending the useful life of the existing mechanical equipment and ductwork.
Improved indoor air quality (IAQ)
The air quality in the building was improved when using the HLR modules.
Using enVerid HLR modules and a reduced ventilation rate, the building was compliant to ASHRAE Standard 62.1 IAQP. Contaminants (i.e., aldehydes, speciated VOCs, and CO 2 ) were successfully maintained below their established threshold values. Figure 7 shows specific measurements of key contaminants of concern. In addition, by reducing the amount of outside air, less particulate matter and hazardous chemicals are brought into the building from the neighboring highway and airport, providing a further improvement in air quality. Studies show that living near highways increases your chance of cardiovascular disease.
In addition, enVerid collected air samples from six locations (figure 4) in the Wellness Center and tested them for all speciated VOCs. The results from an independent lab, shown in figure 8 below, demonstrate the air scrubbing effect of the HLR technology
Faced with higher than desired energy costs and a commitment to high air quality and comfort, the University of Miami turned to enVerid for help. The enVerid project team assessed the HVAC mechanical environments, provided a detailed installation plan and obtained necessary permits.
Installation of three enVerid HLR modules was completed without disruption in HVAC service.
Results: Improved Energy Efficiency and Indoor Air Quality (IAQ):
- 36% average reduction in total HVAC energy consumption
- 41% peak HVAC capacity reduction
- 75% average reduction in outside air
- Per HLR module savings each year
- » $6,500 energy savings
- » $3,100 water savings
- » 19-ton reduction in peak HVAC load
- Better indoor comfort: Relative humidity decreased 10% and air temperature reduced 2.5 0 C
- Improved air quality: Reduced TVOCs to 780 µg/m 3 , formaldehyde to 29 µg/m 3, CO 2 to 753 ppm, and reduced particulate matter from the neighboring highway.
Location: Miami, Florida
Climate Zone: 1A
Industry: Higher Education
Enrollment: 16,000 students
Challenges:Poor indoor air quality and high HVAC energy consumption at state-of-the-art university wellness center
Solution:enVerid HLR Modules installed on each floor of 60,000 ft 2 wellness facility to scrub air of contaminants and reduce the amount of outside air ventilation required
- 36% average reduction in total HVAC energy consumption saving $19,500 per year
- 41% peak HVAC capacity reduction
- 75% average reduction in outside air
- Estimated water savings of $9,200 per year
- Better indoor air comfort: relative humidity decreased 10% and air temperature reduced 2.5˚C
- Improved air quality: Reduced TVOCs to 780 μg/m 3 , formaldehyde to 29 μg/m 3, CO 2 to 753 ppm, and reduced particulate matter from the neighboring highway