Send in the engineering troops

Military facilities present an army of challenges—exacting codes and regulations, stepped-up security issues, and budgetary concerns. Here, engineers who’ve earned their stripes on such projects share advice on how to win the battle.

By Consulting-Specifying Engineer July 24, 2013

Participants:

  • Kevin D. Bomboy, PE, LEED AP, Chief mechanical engineer, STV Group, Douglassville, Pa.
  • David Callan, PE, CEM, LEED AP, HBDP, Vice president, McGuire Engineers Inc., Chicago
  • Robert L. Crance, Mechanical engineer, Black & Veatch, Overland Park, Kansas
  • Joseph H. Talbert, PE, ARM, Project manager, Aon Fire Protection Engineering, Lincolnshire, Ill.
  • William Valdez, Northwest justice and civic sector leader/principal, DLR Group, Seattle

CSE: What engineering challenges do military facilities pose that are different from other structures?

Kevin D. Bomboy: One of the main challenges is providing force protection measures to prevent the building from being a target of terrorism. Required setbacks to eliminate hiding places for bombs dictate the placement of outdoor mechanical, electrical, plumbing (MEP), and fire protection equipment—chillers, transformers, etc.—farther from the building than would be otherwise desirable. Outside air intakes have to be elevated to make it more difficult to execute a chemical, biological, or radiological (CBR) attack on the building. Emergency shutdown systems are required to close all outside air dampers on indication of a CBR attack. Because of the regimented routines of the occupants, plumbing systems in military barracks have to be designed to serve brief periods of very high demand usage in showers and laundries. The stringent requirements for physical, electronic, and information system security that most military facilities have can be challenging to meet.

David Callan: I think there are several engineering challenges and opportunities. The most obvious engineering challenge is security. Depending on the installation, an engineer can encounter a need for physical and environmental security (i.e., CBR protection, cascading pressurization, filtration, and protection of openings). These apply not only to the military, but also many federal applications with national security interests employ these techniques. Since Sept. 11, 2001, we have seen a raising of the bar with respect to security standards. Perhaps a less obvious challenge—one I consider an opportunity—is the breadth and depth of building and systems types an engineer will encounter working with the government and military specifically. We have been involved with housing, office environments, labs, medical buildings, food service, and others.

Robert L. Crance: Military facilities must be designed to support specific criteria beyond what is required by code for commercial facilities. The additional criteria includes provision for force protection, requirements for reduced energy and water use beyond current code required performance, design of facilities for a useful life greater than usually required for commercial construction, and, for some projects, considerations to support continuity of operations. Special criteria necessary to support mission objectives can include higher degrees of air quality achieved through special filtration processes, requirements for redundancies, provisions for system decontamination, and special facility and system post-event survivability.

Joseph H. Talbert: Military facilities have a wide variety of occupancies and uses, which makes for very interesting projects.

William Valdez: Many of the military projects DLR Group is involved in have sensitive compartmented information facilities (SCIF). Particularly unique here is the need to comply with Intelligence Community Directives (ICD) 705-1,705-2, and other applicable ICD and Intelligence Community Standard (ICS) technical specifications for physical security requirements. The nature of this kind of design problem-solving in architectural, mechanical, and electrical disciplines can be very challenging.

CSE: Please describe a recent military facility project you’ve worked on—share challenges you encountered, how you solved them, and engineering aspects you’re especially proud of.

Crance: A recent telecommunications central office facility was designed to provide 36,400 sq ft of new building space used for data/switch functions and administrative support space. The project was located on a very tight site and was required to support integration into the existing infrastructure with minimal impact to ongoing system operations. This project was designed in accordance with the U.S. Green Building Council LEED-NC v2.2 rating system to achieve a Silver certification. Achieving this favorable building performance was accomplished through careful integration of all components of the facility design and by using commonly applied HVAC system solutions with long proven performance histories rather than implementing any developing or unproven technologies that may not support the critical nature of the facility mission.

Valdez: Our engineering firm is extremely proud of having a hand in making Fort Carson, Colo., one of the “greenest” installations in the country. Through the Base Realignment and Closure Commission (BRAC) construction, Fort Carson has gone through an enormous expansion of its facilities and infrastructure. Our firm has been involved in six of the new buildings at Fort Carson during that period. Of the six new buildings, two have been certified LEED Gold while the project requirements only mandated LEED Silver. One of the key success factors for the team has been our integrated approach to sustainability, the process of empowering all engineering disciplines to generate ideas together in creating the sustainable systems for each project. An example of one way that we elevated sustainable design at Fort Carson was through a ground source heat pump (GSHP). This geothermal heating and cooling system serves a 13,000-sq-ft facility. It uses 40 400-ft-deep wells that transfer heat into and out of the building by circulating water below ground where the Earth’s temperature is constant. Prior to our Division Headquarters Band Training Facility project, Fort Carson had never used such a system. Because of this, the biggest challenge was educating the U.S. Army Corps of Engineers that the GSHP system is proven technology, would yield the performance requirements of the request for proposal, and would be easy to maintain. In the end it has become a great success story for both DLR Group and Fort Carson, which led to our use of GSHP systems on all six facilities that we’ve designed there. GSHP systems have become the new standard.

Talbert: One recent project involved the installation of a fire alarm system in a particularly noisy environment. Because the occupants were required to wear hearing protection, all occupants were effectively “hearing impaired.” The solution was to supplement the speakers in the space with visible notification appliances situated so that all occupants could see the visible notification appliances from any point in the room.

Bomboy: STV works on numerous military facilities each year, ranging from headquarters and training facilities to housing and dining facilities; each brings unique challenges. One common challenge is the design/build delivery method very often used for military projects. This delivery approach is very prevalent in military facility projects and requires development of a building MEP design during bidding in sufficient detail and accuracy for our build partner to generate a bid price. This requires skill, diligence, and focus to generate a 30% to 40% design over a very tight schedule. Meeting the energy-efficiency requirements of the project, while holding the construction costs within the authorized funding limits, can also be challenging. It is gratifying that nearly all of our military projects have been able to qualify for LEED Silver certification or better. 

CSE: Have you worked on such facilities in the United States and abroad? If so, what are some of the most notable differences?

Talbert: Facilities outside the U.S. have historically placed a greater emphasis on fire-resistive construction and a lesser emphasis on active fire protection such as sprinkler protection.

Bomboy: In addition to our domestic military facilities, we have worked on military bases in Egypt, where the challenge was to design the buildings simply enough, using standard components, so that replacement parts and repair service could be obtained when needed. For military projects, most of the MEP equipment is procured from U.S. manufacturers. However, electrical power in most overseas locations operates at 50 Hz versus 60 Hz in the U.S., and has different delivery and usation voltages; equipment specifications must be carefully tailored to address these differences. Limited availability of skilled local labor and language issues drove an increased level of detail required for successful bidding and construction.

Callan: I have experience working on military and Dept. of Homeland Security projects in the U.S. and abroad. Because these facilities are usually subject only to U.S. codes, regulations, and institutional standards, the main challenges for MEP engineers are climate, utility provisions and their reliability, and available materials and labor.

Crance: We deliver many different project designs both domestically and overseas. The challenges with delivering overseas projects depend on the sponsoring agency and its project goals. Projects supporting country building or redevelopment are often required to be designed around locally available materials and products that will be constructed using locally available craft labor with greatly different skills than we are accustomed to in the U.S. Other considerations for delivering overseas projects include movement of material and equipment across multiple borders, lack of documented codes and standards, and widely varying business practices, both formal and informal. 

CSE: What cutting-edge energy efficiency projects have you worked on at a military facility recently? What design aspects or products were included?

Valdez: The RAIDRS Space Control Facility at Peterson Air Force Base in Colorado is a new two-story building and is a mission critical facility. Unique features of RAIDRS Space Control Facility include the use of a transpired solar collector system, and an accessible floor displaced air distribution system. Transpired solar collectors or solar walls are used as a thermal preheat system, providing passive preheating of outside air in the winter months. Energy codes require high ventilation loads, which represent an enormous energy expenditure given the tremendous volume of outside air that has to be continuously brought in and then heated over the entire heating season. A solar wall system consists of panels that are mounted roughly 6 in. from the exterior south-facing wall of the facility’s main mechanical room. The cavity created between the exterior wall and the solar wall panels fills with outside air that is heated by the radiant heating of the panels. The heated outside air in the cavity is then drawn into the air handling units in the mechanical room and reduces the amount of thermal energy that is needed from natural gas.

Bomboy: Every military project has an energy-efficiency requirement, so most projects take advantage of a combination of energy conservation measures. Our designs have used dedicated outside air systems (DOAS) with energy recovery heat wheels, radiant heating and cooling in floor slabs, condensate recovery, and solar hot water systems. We have also performed energy recovery to preheat domestic hot water by capturing heat energy from shower drains. Efficient lighting systems and lighting controls—task lighting, LEDs, zone controls, etc.—figure into all our designs. In some cases, rooftop photovoltaic (PV) systems have also proven cost-effective. Recent projects make use of GSHP systems to reduce a facility’s annual energy consumption. Depending on geographic location, some of these systems are incorporating supplemental heat rejection capabilities in the form of dry coolers or evaporative cooling towers to address the heating/cooling load imbalance. Other recent projects use solar water collectors to offset energy use associated with heating domestic water. Air-side energy recovery is implemented through use of air-to-air energy recovery systems where dedicated makeup air units are used to enhance energy recovery efficiency. These applications are being incorporated on both domestic and overseas projects. 

Callan: The projects I have worked on were more utilitarian in nature. While energy conservation has always been of primary concern, we achieved these goals with modest investments. 

CSE: How has the military’s emphasis on “net zero” systems affected your work on such projects?

Callan: I applaud the Army’s desire to pursue net zero goals. The army has been a leading force in many areas including science, engineering, and education. Net zero energy buildings (NZEB) are an achievable goal with perseverance and time. However, like my grandfather said, “it’s the journey, not the destination.” My personal engineering philosophy is one of continuous improvement. Some changes will be small and gradual. Some changes will be monumental. Though I agree with the late Daniel Burnham, who said, "Make no little plans. They have no magic to stir men’s blood and probably will not themselves be realized," I recognize that many of the engineering feats of today were perfected with gradual and continuous improvement. In other words, no matter how great the goal or objective, the first attempt will be refined and improved over time. 

Current new construction and renovation projects focus on conservation of both energy and water as most of these projects are single facilities. Opportunities to achieve the benefits of waste energy reuse or energy repurpose are limited by the scale afforded by single facilities. For many projects, it is challenging to incorporate the most beneficial systems into the facility design and remain within the first cost constraints of the project. Looking forward, it should be expected that larger-scale projects that provide a total energy solution at an overall installation level will be required to achieve the net zero vision. 

Bomboy: The first step to achieving net zero is to reduce energy consumption. Whether a project has a net zero goal or not, it is important to find cost-effective alternatives for driving down the building energy consumption; photovoltaic systems and solar hot water panels are common considerations. To achieve true net-zero performance, it is essential that MEP collaborate closely with architecture to optimize building footprint and orientation, fenestration, building skin performance—passive or active—and light shelves/shading, in order to treat the building not as a collection of components, but as a coordinated system.