By Ellen Dickson, FAIA, ALA, LEED AP, NCARB, NCIDQ
The new Army National Guard Readiness Center and Army Aviation Support Facility built in Kankakee, Ill., is a center of civic heritage designed to celebrate and inspire those who will be using it: the soldier.
Situated 60-mi south of Chicago and home to three tenants— Company B, 1st Battalion, 106th Aviation; Company B, 935th Aviation Support Battalion; and a Medivac unit—the facility opened in November 2017 and will serve as a fresh and bold face for the military, playing a significant role in attracting new recruits. The previous facility at Midway Airport was impacted by a diminishing safety zone between the apron and taxiway caused by extended runways and the increased size of commercial airliners. Construction on the new building began in 2014.
DESIGNED TO INSPIRE
While the new facility’s progressive architecture is an open tribute to those who use it, the backbone of the building is its sustainable design, led by its energy efficiency advancements.
A programming goal from day one was the pursuit of LEED Silver certification and the facility was certified for 54 points, a step above the State of Illinois requirement of LEED Silver with an accumulated 50 points. This visionary building now stands as a symbol for the National Guard—and it is all the more impressive because of its dedication to sustainability.
Due to the nature and functionality of the facility, there were several influential environmental factors encountered during design and construction: the sheer size of the building and adjoining hangars, budget constraints, and occupancy. Determining which renewable energy measures to pursue also had to be evaluated. Geothermal technology was an option considered for energy production to increase sustainability; however, because the facility is primarily used on the weekends, the life-cycle cost payback period was over 100 years and did not satisfy the cost/benefit analysis. A wind turbine was another alternative energy source, but the proximity of the neighboring airport ruled it out. Had those options been feasible, the facility conceivably could have reached net zero energy, producing as much energy as required to operate.
Windows played an important role in the sustainable design, as an extensive daylight-harvesting system. Informed by an in-depth daylight analysis and lighting study, the exterior wall design reduces energy consumption while boosting morale with the incorporation of natural light and exterior views in as many areas as possible. The entire south façade is glass and colored polycarbonate panels. This creates a pattern that mirrors a soldier’s digital camouflage, allows the optimum amount of light infiltration while minimizing conditioning energy use, and increases thermal performance. Each 3-ft by 8-ft panel has multiple cells, or ribs, measuring approximately 1.75- in deep. The cell depth is what helps the panels provide more insulative property than a glass curtain-wall system. Those window materials were chosen carefully, balancing budget and performance with the appropriate amount of diffuse light and heat sustained in the building.
Not only does the amount of natural light reduce the energy consumption, but the windows provide an opportunity to connect those in the building with nature. In fact, 84 percent of regularly occupied spaces have access to daylight without glare. Solar-tubes bring natural light into interior spaces, and shading devices prevent direct sunlight glare. Each of the open office spaces receives outdoor views and non-office areas have skylights and windows to ensure all occupants have access to exterior views and natural light—improving quality of life, productivity and occupant health, and reducing absenteeism.
CONTROLLING BUILDING COMFORT
Building comfort is provided by a variable refrigerant flow (VRF) heat recovery system that allows simultaneous heating and cooling of spaces within the building. The heat extracted from spaces requiring cooling is put to use in spaces that need heating, reducing the mechanical cooling needed and saving energy. To enhance the VRF system performance, engineering consultant IMEG located the condensing units within a fully enclosed penthouse to provide them with greater protection from thermal extremes, and to ensure full heating capacity in the winter. Louvers in the penthouse open in the summer to allow heat rejection for cooling.
A radiant heating floor system is installed throughout the hangars and is heated by three high-efficiency condensing boilers. The system was deemed to be one of the project’s priorities in order to provide a comfortable working environment for those maintaining the helicopters. Radiant tubing with glycol is also located under the hangar doors and is heated by another two high-efficiency condensing boilers to prevent the doors from icing up and to ensure they will easily open under severe winter conditions. A glycol snowmelt system extends 20-ft beyond all hangar doors to keep the apron area clear of snow.
TESTING THE BUILDING ENVELOPE
Air-tightness tests, a more common practice on residential buildings, are not typically required for larger institutional facilities. However, designers knew that performing the test would validate the quality of the building’s high performance exterior wall system. The Kankakee Readiness Center and Army Aviation Support Facility is a hybrid building, housing both offices and a training facility, which makes implementing an airtightness test more difficult.
An air-tight building envelope helps to reduce heating and cooling energy consumption by limiting the impact of the exterior temperature on the interior temperature. The outcome is smaller, more efficient heating and cooling systems, lower energy usage, and an increase in occupant comfort. Furthermore, water vapor can get into the building through air leaks, which can lead to the deterioration of building elements. Despite the difficulty of creating an air-tight facility that is so large and multipurpose, Bailey Edward, in coordination with the general contractors and subcontractors, was able to make a building that passed the airtightness standard on the first attempt. The airflow of the building envelope was recorded at less than 0.25-cfm/ft² at a pressurization of 75-Pa. That is equivalent to 4,200-in² of leakage area in 224,900-ft² of building envelope surface area.
FINDING SUSTAINABLE SOLUTIONS
For seven years, sustainable technological solutions have driven the design and construction of the Kankakee Readiness Center and Army Aviation Support Facility—from daylight harvesting to radiant flooring to an airtight building envelope.
These advancements will continue to assist the Illinois National Guard, by reducing energy costs 32.2 percent and boosting morale for the servicemen and women for whom the facility was built.
Ellen Dickson, FAIA, ALA, LEED AP, NCARB, NCIDQ, is Founding Principal, Bailey Edward; firstname.lastname@example.org.
[Article first published in the March-April 2018 issue of The Military Engineer.]