The average dry bulb temperature of St. Croix is 82 F, with temperatures remaining relatively constant throughout the year with a typical swing of 10 F. There is very limited seasonal variation in temperature with modest diurnal temperature swings (day-night).
The relative humidity in St. Croix also has fairly limited seasonal variation, averaging approximately 70 percent and generally staying between a low of about 60 percent and a high of 90 percent.
A wind rose diagram plots the annual frequency of wind speed and direction, with the prevailing winds predominantly from the east and southeast and velocities most commonly in the range of 3 to 6 meters per second.
The solar radiation on site is relatively high, averaging 5.4 kilowatt-hours per square meter per day, with only 40 percent average annual cloud cover.
Figure 3 shows the sun path at the site, the park boundary, 100 year floodplain, and an
archeological zone on the site. This exhibit was developed for the partners during the Marine Research and Education Center’s conceptual design process and is provided here as guidance to the students for campus master planning purposes.
Figure 4: Psychrometric Chart
Figure 4 provides a graphic representation of human comfort conditions, plotting dry-bulb temperature, wet-bulb temperature, and relative humidity. The Marine Research and Education Center program contains both museum storage and laboratory spaces which have both temperature and maximum relative humidity requirements of 60 percent.
Green building rating systems can provide an effective, holistic framework for both addressing the environmental impacts of building design and construction as well as setting concrete performance targets to inform design. Additional sustainable design resources may be found in the Resources section of this program.
Design and engineered systems must acknowledge the surrounding environment and occupants in regards to maintenance, accessibility, durability, and cost feasibility.
A key goal of the Marine Research and Education Center is the demonstration of environmentally-responsible, sustainable development. A key element of sustainability is that the project be designed in response to local environmental challenges and in harmony with local conditions while supporting cultural awareness.
A 2005 survey identified air quality and sewage as the environmental areas of greatest concern to St. Croix residents. The island is home to the HOVENSA Refinery, the second largest oil refinery in the United States and one of the 10 largest oil refineries in the world. In 2011 the U.S. Environmental Protection Agency began a 3-month study of air pollution in response to community concerns about the health impacts of airborne chemical releases from the refinery. Additional air quality threats are posed by the Richmond power plant near Christiansted, St. Croix, which produces electricity using oil-fired generators.
Highly publicized raw municipal sewage discharges have caused periodic fish kills and beach closures. The majority of homes on St. Croix are served by septic systems. Due to poor soil conditions, steep slopes, and limited regulations, untreated effluent from failing septic systems also poses an environmental challenge, both to human health as well as the marine ecosystems that are the focus of the Marine Research and Education Center. Erosion and sedimentation resulting from stormwater runoff caused by poor soils, steep slopes, and conventional development further stress the marine ecosystem. Additionally, the services conventionally provided by municipal systems in other locations are much more expensive and less reliable on St. Croix.
There is very limited freshwater supply from 'conventional' sources. There is little ground water and obtaining municipal water from a desalinization plant is energy-intensive and expensive. Municipal electricity is among the most expensive in the U.S., and the supply is unreliable with frequent, unpredictable interruptions which pose a particular challenge in a research environment where reliability is critical.
An environmentally responsible facility on St. Croix should be designed to directly address the local environmental challenges of air pollution; water pollution (both from sewage and stormwater); limited water supply; and polluting, expensive, and unreliable electricity.