Environmental control panel close-up

Environmental Control and Monitoring

Environmental Control

All animal housing rooms managed by DAR have automated, centralized and individual temperature direct digital control (DDC) systems. Temperature control within the animal research facilities is independent of other areas of buildings such as laboratories and administrative areas. Almost without exception, terminal reheat coil valves, regulating the heat supplied to animal rooms are designed, should they fail or malfunction, to be positioned in the closed or last known position – this design feature prevents animal rooms from over-heating to levels typically lethal for mammals should the valve break. The default specification is for temperature to be controllable within a range of 65-86°F and +/- 1°F of the set point year-round. Environmental set-points for temperature are physically established and managed by the Controls Information Center (CIC) of Facilities Management/Campus services acting only under the instruction of the DAR. The temperature set-points in general and for various species are listed below.

  • General: 72°F
  • Rabbits: 68°F
  • Amphibians: 65°F
  • Fish, tropical: 74°F
  • Fish, temperate: 65°F (also for marine fish)

Relative humidity is controlled zonally within animal research facilities with the default for it to be maintained within a range of 30-70% and within 10% of the set point year round and optimally at 40-50% relative humidity for rooms designated or possibly to be used for rodents.

Animal housing rooms and other select areas, such as cage wash resources and necropsy, minimally exchange 10-15 changes of fresh air per hour at a consistent rate. Some facilities have the feature of adjusting air exchange within the range of 8-20 air changes per hour. No room air is recycled in any ARF. While some rooms have bidirectional and adjustable (reversible) control of airflow, the default for animal housing rooms, biocontainment areas, and soiled sides of cage wash rooms is for them to be under negative differential air pressure with respect to corridors (and, for the latter, clean sides of cage wash resources). Clean cage wash areas, large animal surgical suites, and storage areas by default are under positive differential air pressure.

In the event of power failure, exhaust fans are connected to back-up power to provide sufficient exhaust during down times to maintain negative room air balance and ventilate all animal rooms. All room and building HVAC systems are professionally assessed and balanced for ventilation at least every 3 years. Buildings or rooms that develop ventilation problems as assessed by the research or animal resources staff are reported to Campus Services. CS has staff assigned to each building who address these problems or call in HVAC specialists to address them. The containment suites designed to ABSL3 standard have a computerized monitoring system for air pressure and HEPA filtration of exhaust air. If pressure differentials go outside preset limits, the air intake fan shuts down, local audio and visual alarms are set off, and alarms are sent to a call list. DAR personnel may periodically check pressure differentials in animal facilities using smoke sticks.

All DAR facilities, with the exception of HSRB Phase 2, are illuminated with cool white fluorescent light fixtures. By default, animal housing areas are on a 12 hour x 12 hour light/dark cycle without twilight with most 7 AM on and 7 PM off and adjusting to remain synchronized with Eastern Standard Time (EST) and Daylight Saving Time (DST). Investigators conducting experiments or collecting data that is sensitive to lighting are advised to schedule experiments around these events. Animal rooms are windowless and the light cycles are controlled automatically by a computer based system under the direct management of DAR. The system does allow for light cycles to be adjusted to enable any desired ratio of light-to-dark during a 24-hour period including reverse light cycle, 24-hour darkness, or continuous illumination. Rooms with altered lighting schedules are noted with signs posted on the entry doors. Many rooms have two lighting levels, a basal level and a work level controlled by a timed override switch. Intensity varies from 15-75 foot-candles. Some rooms have red illumination over-ride instead of or in addition to white light.

Environmental Monitoring

Environmental monitoring primary responsibility is that of the DAR using the Siemens Building Technologies' APOGEE building management and control system and InfoCenter Suite with battery back-up. This computer-based technology allows both local and remote access and control and provides continuous temperature, relative humidity and photoperiod monitoring in animal holding rooms and differential air pressure alarms for biocontainment areas using sensors collecting real-time data. The temperature and relative humidity sensors are contained in waterproof enclosures and are surface mounted in the animal housing rooms, including within exhaust ducts. Current transducer sensors are located in the lighting circuitry for all rooms and to outlets powering pumps and filters in the fish facility housing marine and temperate, fresh-water species. The InfoCenter Suite allows for data archiving, charting, tracking, analysis, and reporting. Historical queries and reports can be made of environmental conditions or alarms by building, room, environmental parameter, and date/time via a list of on-screen options or pull-down menus. Data is available as the mean +/- standard deviation and/or high and low range and in both numeric and graphic formats.

The Siemens system has the capability for high/low warnings and emergency alarms for selected parameters set independently for each room: temperature extreme or excessive variability; relative humidity extreme; continuous, excessive or interrupted periods of light or darkness; positive differential air pressure (ABSL3 areas); RO drinking water treatment and supply system for low reservoir water levels and excessive or failed electrical supply current to water system pump motor; electrical currents to outlets powering pumps and filters for some aquatic species. Alarms outside preset limits are sent by text, email and voice to a customized, prescribed call list which includes the DAR office, Facilities Management Control Information Center (CIC), and selected DAR first responder staff members. The alarm provides the time/date of onset of the alarm condition, the physical site (down to the room) and specific environmental parameter in alarm.

The DAR also has mobile HOBO (Onset Corp.) digital monitoring units (temperature, relative humidity, photoperiod), a hand-held digital thermohygrometer, and infrared, handheld, non-contact thermometer for purposes of verifying environmental conditions.

Environmental Manipulation for Research Purposes

Since the aspiration of DAR is to provide wholesome and consistent environments to facilitate the conduct of robust and valid research for all users, including the preponderance of those sharing rooms, deliberate alteration/manipulation of environmental set points for temperature and photoperiod to meet specific research need is relatively rare. Given the zonal nature of relative humidity control and the high infrastructure and operational costs required to humidify or dehumidify supply air in order to fix and maintain a range of relative humidity values pinpointed across a wide-range of temperature settings, macroenvironmental relative humidity can only be tightly manipulated using cabinets, chambers, boxes or enclosures specifically designed for or adaptable to this purpose. For the same reason, varying ambient temperature set points, altering photoperiod properties, and providing light-tight environments are likewise best accomplished using chambers or equivalents designed to accommodate these specific research needs.

Where it is necessary and desirable to manipulate temperature settings or light cycle characteristics on a room-wide basis, this can only be realized with IACUC approval and in areas used by a single user or where all multiple users unanimously agree to the change in the environmental conditions. While light cycles can be rapidly changed, adjustments in temperature set points may require hours to a day or more for the ambient temperature to equilibrate. Be that as it may, the complexity of environmental control, monitoring, alarm receipt and response responsibilities, and conduits of communication within DAR and between DAR and FM, require a minimum of 5 business days for new interventions (i.e., the parameter manipulation is unprecedented for the PI and/or the space) to be enacted and 48 hours (i.e. 2 business days) thereafter and where the PI has an established history of environmental manipulation in a specific room. A formal submission is required to enable accurate documentation and recording of each environmental change request and accompanying alarm adjustment and must be accomplished using an Environmental Control Request form submitted to the DAR Environmental Monitoring and Security team by fax, hand-delivery or pdf attachment to email. This service and coordination with the CIC is handled centrally in the DAR office and facility managers/supervisors are officially informed of changes and authorized only to take appropriate related actions upon notification from the DAR office. Animal facility supervisors and managers are ordinarily not capable of implementing changes to the environment. The only exception is that of a few, scattered cases of photoperiod control using residual, manual light timers under local animal facility supervisor/manager command.

In rare, scientifically-justified cases approved by the IACUC, the DAR may relinquish environmental control authority and alarm response responsibility to an investigator although this will require, beyond IACUC approval, a written PI-DAR Memorandum of Understanding (MOU).