Meeting the Challenges of Commissioning Vivariums
An interview with Charles Bean, CBCP
by Linda Goodspeed
Vivariums (animal laboratories) within hospitals, universities, laboratories and research institutions, present special heating, ventilating, and air-conditioning (HVAC) commissioning challenges. Not only do vivariums require stricter air quality standards and controls within their own spaces and subspaces, they are usually housed within larger facilities, posing cross contamination issues.
“Vivariums are critical control environments,” said Charles Bean, a Senior Engineer at EH&E. “Temperature, humidity, air flow, and lighting all have to operate within certain bands. If they don’t, it can impact the integrity of the experimentation.”
Improper lighting, for example, or large temperature swings – even though the average temperature may be correct – can affect the animals’ metabolism and eating, sleeping, and mating habits, which in turn can affect experiments. Improperly controlled humidity can potentially lead to microbial growth in cages and ductwork, also affecting experiments. “A properly performing system eliminates the laboratory environment as one of the variables in the researchers’ experimentation,” Bean said.
In addition to the many air quality and contamination issues within their own environs, vivariums also pose potential air quality risks to the rest of the facility. “Because vivariums operate within larger facilities you have to separate the HVAC and mechanical systems and make sure you have the correct systems dedicated to the animal facility, so there is no air recirculated from the animal facility back into other areas of the building,” Bean said.
Building commissioning is a quality assurance process that helps to ensure that equipment and systems perform as they were designed and intended to operate. Vivariums pose a higher level of issues than other types of laboratories and therefore require a higher level of commissioning expertise and experience. Bean and EH&E’s commissioning team have commissioned over five million square feet of institutional and commercial construction and many of these facilities include critical environments such as vivariums, clean rooms, and laboratories.
Primary and Secondary Considerations
Within vivariums themselves, there are primary enclosures (cages) and secondary enclosures (rooms that hold the cages). Sometimes the primary enclosures need a specialized environment and are fed by HVAC systems directly. Supply and exhaust ducts are hooked directly to cages to create individually ventilated enclosures. “In these situations if heating and cooling and humidification are not working properly, cage conditions could cycle outside extreme limits and potentially damage the animal or the experiment in progress on the animal,” Bean said. Commissioning verifies proper air delivery, heating and cooling, and humidification for directly fed primary enclosures. Commissioning also ensures that the primary enclosure functions properly as a protective environment or a containment environment by ensuring the right supply and exhaust airflow relationship exists.
Within the secondary enclosure – the room housing the cages – commissioning confirms airflow and pressurization, including correct space-to-space pressure and airflow gradients, consistency of temperature and humidification, function and proper levels of lighting, and performance under emergency power.
A 3 Phase Process
Commissioning a vivarium starts at the design stage. Working in concert with the building owner and design team, EH&E reviews every detail of the facility’s design with respect to air exchange rates, filtration, pressurization, airflow, and lighting as well as work flow and space usability. “We work with the design team to make any adjustments necessary to the design to conform to the building owner’s needs and existing codes and standards,” Bean said.
Phase two is the construction phase. EH&E oversees quality control for the construction and installation of systems, ensuring they conform to project specifications, codes and standards, and good workmanship.
The third phase of the commissioning process is the testing phase. EH&E functionally tests every piece of equipment associated with the vivarium, including HVAC, exhaust air systems, animal watering systems, cage washing systems, alarms, lighting, autoclaves, and other equipment.
Once commissioned, vivarium environments should be monitored regularly according to the National Research Council.1 EH&E recommends that this regular monitoring include re-commissioning annually. Bean said that as part of the re-commissioning, it is a good idea to monitor performance of the facility during hot summer days as well as during cold winter days. “On a hot summer day the concern is whether you are cooling and dehumidifying the air adequately. During the winter, the concern is the function of humidification systems and whether or not humidity control undergoes excessive cycling; a condition which is common with some types of systems.”
As part of the commissioning of vivarium facilities, it is equally important to routinely maintain the proper operation of the equipment and systems. EH&E engineers coordinate training for facility staff on HVAC, mechanical systems, alarm indications, and other specialized equipment associated with these areas. EH&E’s industrial hygiene staff also routinely conducts several health and safety training programs for laboratory personnel. Provision of training is an additional quality assurance measure that helps to maintain the proper environment within the vivarium at all times.
While commissioning and re-commissioning vivariums often produces energy cost savings, the primary objective is performance. “Because vivariums are high air exchange facilities, they use a lot more energy than a typical office-type environment,” Bean said. “Due to the sensitivity of the research conducted within these environments, performance is critical. The investment in these spaces is significant and the consequences of not commissioning could be very costly.”
Charles Bean is a Certified Building Commissioning Professional (CBCP) and Associate Director, Commissioning Services / Senior Engineer at EH&E. His commissioning experience includes numerous healthcare, research, and laboratory spaces in addition to commercial facilities. For more information contact Charlie at CBean@eheinc.com.
- Guidelines for the Care and Use of Laboratory Animals. National Research Council. 1996.