AIA/COTE Top Ten Green Projects
Charles Hostler Student Center
|Photo credit: Paul Crosby Studio|
Beirut is rebuilding after years of civil war and lacks the robust municipal infrastructure that would be taken for granted in the United States. During summer months, rolling blackouts occur regularly as peak power demands exceed generating capacity. Additionally, political instability can disrupt the public utilities for extended periods of time. To address these issues, it was necessary to integrate backup systems for water and power supply into the project. Many of the sustainable systems in the project are used to provide this backup in a dependable, efficient, and optimized manner.
In addition to emphasizing air movement, the design incorporates radiant cooling for select areas of the buildings where larger gatherings occur on a regular basis, such as the gymnasium, pool, theater, squash courts, and café. Evaporative and radiant cooling are also used in the outdoor courtyard water-walls. Conversely, the project’s solar panels heat water for the pool and for other uses. Floor piping directs the water into the pool area to warm the floor surfaces. During the summer, the excess thermal energy can be used for chilled water production.
The Hostler Center uses excess steam produced by AUB to provide additional heating. The ventilation system uses displacement cooling. Large concrete-slab integrated heat exchangers satisfy a major portion of the cooling load. The additional air system provides dehumidified, fresh air. Compared to an all-air system, this system reduces consumption significantly.
An advanced water-cooled centrifugal and absorption chiller provides chilled water, heat rejection is through an onsite seawater well and heat exchanger. A Building Management System (BMS) operates lighting controls and temperature and humidity controls according to outdoor conditions.
In Beirut, the spring, summer (with the exception of August), and fall are typically hot and dry. Winter brings cooler temperatures and rain, mostly during December and January. The regional climate could be described as semi-arid and strongly influenced by the Mediterranean Sea. Average daily temperature ranges are narrow and humidity varies between 60%-72% over the year. The interaction of topography, local urban form, and prevailing wind patterns significantly affect the AUB campus and cause very specific environmental conditions.
AUB’s Master Plan recommended that buildings follow the standard east-west orientation to minimize surfaces oriented toward the sun. A more careful analysis of the shading properties of rectangular volumes demonstrated that north-south courtyards actually provided 40% more shade throughout the year at a latitude of 33 degrees. This enables the courtyards to open up to prevailing sea breezes. By reorienting the buildings on their north-south axis with the primary masonry facades facing east and west, the fanning nature of the plan places the buildings in close proximity to one another, achieving a substantial degree of self-shading while shading adjacent spaces. A highly insulated envelope and solar control windows provide comfortable interior conditions without any heating and cooling in shoulder seasons.
|Annual Purchased Energy Use|
|Fuel Oil (No. 2, diesel)||4,290 MMBtu||4,290||41.1|
Annual On-site Renewable Energy Production
Total Annual Building Energy Consumption
|Total On-Site Renewable||330||3.17|
|Annual End-Use Breakdown|
|Plug Loads and Equipment|
|Domestic Hot Water|
|Unspecified End Use||2,900||27.8|
|Building Energy Load|
|Cooling Load||271 ton||385 ft²/ton|
|Connected Lighting||224 kW||2.15 W/ft²|
Data Sources & Reliability
Energy data is based on 104,329 ft2 of conditioned building space (excluding approximately 100,000 ft2 of unconditioned underground parking area) out of 204,000 ft2 total project area.
- Use deep well water as a sink for direct cooling
Solar Cooling Loads
- Shade south windows with exterior louvers, awnings, or trellises
Non-Solar Cooling Loads
- Use siting and topography to enhance summer breezes
- Provide an open floor plan and openings located to catch prevailing breezes
- Use waste heat from mechanical systems to heat water
- Use centrifugal chillers
- Use water-cooled mechanical cooling equipment
- Use evaporative cooling
- Use night sky radiative cooling
- Use hot water heat distribution
Other Energy Sources
- Consider a cogeneration system to provide heat and electricity
- Use displacement ventilation