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.
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 (CO2) 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 ft2 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 12th 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 HVAC 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 CO2, formaldehyde and VOCs. The HLR module also has a set of sensors measuring temperature, relative humidity, CO2 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.
Energy and air quality measurement methods
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 14th until September 21st, and then again in 2017 from June 6th until September 27th. 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, CO2, 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.
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.