•  Carrier


At the Forefront of Sustainability

As the National Institutes of Health faces challenges in improving the energy efficiency of its operations, it has engaged U.S. Public Health Service environmental engineers to explore solutions from a pollution prevention perspective, to use strategies that lower utility consumption and reduce greenhouse gas emissions.


By Lt. Cdr. Leo Angelo Gumapas, P.E., M.SAME, USPHS


NIH Bethesda Campus


Environmental engineers frequently address environmental pollution retroac­tively, focusing on remediation and abate­ment measures. The National Institutes of Health (NIH) has recognized there can be an opportunity to proactively help prevent pollution by engaging environmental engi­neers to explore solutions to improve the agency’s facility operations—in essence, to stop the pollution before it starts. 

NIH, an operating division of the U.S. Department of Health and Human Services, is the primary federal agency charged with conducting and supporting biomedical research. NIH is headquartered in Bethesda, Md., on a campus hosting nearly 12.6-million-ft² of facility space. Approximately 70 percent of the facility space at the Bethesda campus is devoted to energy-intensive laboratory and clinical center activities. These spaces require more frequent air exchanges than office space to meet health and safety standards, and they host an abundance of energy-intensive scientific and medical equipment. These two factors challenge NIH to maintain its mission-critical activities while also improving its energy efficiency and reduc­ing greenhouse gas emissions.

The federal government has become increasingly aware of the human health and environmental impacts of its facili­ties—particularly on the nation’s energy and water resources and greenhouse gas emissions. Within the past five years, the government has put forth a series of laws and executive actions with the intent of integrating sustainability into site planning, design, construction and maintenance of federal facilities.

In response, NIH has developed programs and policies to enhance environmental stewardship through pollution prevention, resource conservation and sustainable devel­opment. The agency recruited U.S. Public Health Service environmental engineers to compile its greenhouse gas inventory and develop strategies to reduce its carbon footprint. The inventory included data on utility consumption, employee commut­ing behavior, waste disposal, refrigerant fugitive emissions, wastewater treatment operations, and vehicle fleet fuel consump­tion. Emissions from purchased electricity and stationary combustion (boilers, emer­gency generators, cogeneration systems) account for approximately 80 percent of the total greenhouse gas emissions. Engineers analyzed NIH operations and identified three large sources for targeted reduction efforts: reducing the amount of electricity that operates laboratory freezers; improving the efficiency of boiler and chiller opera­tions in the Central Utility Plant; and opti­mizing the synergy of the preheat chiller coil operations to reduce the use of reheat for laboratory ventilation systems.



The NIH Bethesda Campus has nearly 2,200 Ultra-Low Temperature (ULT) freez­ers in operation. A ULT freezer is designed to reach -86°C (-123°F). An older, inefficient ULT freezer can use as much as 20-kWh/ day of electricity—equivalent to the daily electricity usage of a 2,500-ft² house.

CPU at NIHA newer, high efficiency ULT freezer will use only 15-kWh/day. In fall 2012, NIH replaced 98 old ULT freezers with 70 new ones. This action has reduced energy consumption by 591,000-kWh yearly, saving $65,000 annually in energy costs. The energy savings alone will cover the cost of the new freezers in less than 10 years. The more effi­cient freezers also will reduce greenhouse gas emissions by 272-T annually.



The Bethesda Campus Central Utility Plant (CUP) is capable of generating 800,000-lb/hr of steam at 165-lb/in² gauge, 60,000-T of chilled water at 42°F, and 6,600-ft³/min of compressed air for distribution to the campus. In FY2012, the CUP utilized over 360-million-gal for cooling tower make-up, which cost NIH $2.4 million. A study of the water quality of NIH’s cooling towers in May 2014 found the tower’s recycled water contained high levels of Total Hardness and Total Dissolved Solids, which tended to form scale, depos­its, and induced corrosion. This resulted in reduced heat transfer, increased blow down frequency, and high make-up water use.

To address this, NIH is installing a fully updated automated water treatment system and intends to bring on additional staff to monitor for water treatment issues proac­tively and mitigate potential issues that may compromise the plant’s operations. With improved water treatment, it is esti­mated the cooling towers can be operated per design to use approximately 63-million-gal annually. This will save $460,000 in water costs alone. NIH maintenance tech­nicians, plant operators, shift supervisors and senior management are engaged in weekly meetings to establish standards so that equipment can be operated per design and maintained in accordance to manu­facturer and industry recommendations.



Research labs on the Bethesda Campus are supported by the chilled water, steam and compressed air the CUP generates. These labs are designed to support six to 10 air changes per hour (ACH), and sometimes upward to 15-ACH for animal holding rooms. NIH’s Design Requirements Manual requires every lab be designed to support an energy utilization index of 8-W/ ft² of equipment load. Energy utilization index assumes a heat load from equipment that must be considered in the sizing of air handling equipment. Many universities have started to use lower energy utilization indexes based on their own studies and new technologies, which are providing the ability to reduce ventilation rates in labs.


NIH has leveraged Public Health Service engineers to proactively reduce its carbon footprint. As a result, NIH ORF has been able to prove to the scientific community through the ULT freezer replacement program that it has a model to reduce utility consumption and cost, leaving additional funds available for research in the laboratories. 


NIH’s Office of Research Facilities (ORF) wanted to study the campus’ energy utili­zation index to explore the possibility to reduce the demand for chilled water and steam in the labs. NIH ORF assembled a team of electricians and engineers to complete a comprehensive study to gather and analyze electricity data on a granular level. Nearly 350 pieces of lab equipment were inventoried in six labs in Building 6. Each piece of equipment was mapped to one of 66 circuits. The electricity consumption for each piece of equipment was measured for a one-week period. Air supply and exhaust flow rates, reheat valve position, and room temperature data was gathered by the Building Automation System over the energy measurement period. After analyz­ing the data, the study showed NIH labs operated less than the 8-W/ft² standard. And certain labs may be over ventilated, based upon current equipment load as evidenced by the increased reheat operation that was observed from the data.

Through the energy measurement studies conducted during the freezer replacement program and the energy utilization index study, a number of issues have been identified in the Bethesda Campus labs. NIH is starting to look at implementing the following strate­gies to further reduce its electricity demands:

  • Explore utilizing liquid nitrogen freezers and water cooled freezers.
  • Implement an NIH-wide freezer main­tenance program.
  • Consolidate lab freezers through clea­nouts and high density solutions.
  • Install timers on bench top lab equipment.

The more efficient freezers, proposed projects in the research labs, the water treat­ment, and standard operating and main­tenance procedure development projects in the CUP will lower electricity, fuel oil, natural gas and water consumption, which will help in further reducing greenhouse gas emissions at the Bethesda Campus.



NIH has leveraged Public Health Service engineers to proactively reduce its carbon footprint. As a result, NIH ORF has been able to prove to the scientific community through the ULT freezer replacement program that it has a model to reduce utility consumption and cost, leaving additional funds available for research in the laboratories. Implementing energy reduction strategies developed from plug load studies done in its labs and addressing issues in the CUP provide mechanisms to further reduce NIH’s utility consumption and carbon footprint while increasing the reliability of its operations.

Ultimately, pollution prevention accom­plished through reducing greenhouse gas emissions proactively aligns with both the Public Health Service’s mission to “protect, promote, and advance the health and safety of the nation” and NIH’s mission to “enhance health, lengthen life, and reduce illness and disability.”



Lt. Cdr. Leo Angelo Gumapas, P.E., M.SAME, USPHS, is Greenhouse Gas Program Manager/Environmental Engineer, Office of Research Facilities - Division of Environmental Protection, National Institutes of Health; 301-402-7871, or This email address is being protected from spambots. You need JavaScript enabled to view it..