By James J. SadlerAmerica’s buildings face a new reality when it comes to safety. The concentration of people and property, coupled with increasingly open floorplans and numerous entry/exit ways, make commercial buildings an easy target for suspicious activity that can go undetected.Significant attention is now being given to the vulnerability of buildings to attack through the heating, ventilation, and air-conditioning (HVAC) systems. Since HVAC systems can be misused as an effective means of transport, they rank high among the many methods available to spread hazardous contaminants throughout a building. To address security concerns about the environmental systems, prudent facilities managers are turning to HVAC contractors for solutions that cover a range of preventive, detection, and response initiatives. Evaluating HVAC security and air quality initiatives in commercial buildings requires a thorough understanding of multiple technical disciplines, so carefully consider the qualifications of your provider while reviewing potential retrofit proposals. How to access a facility, what vulnerabilities to look for, and immediacy of implementation are some of these issues. In a prevention role, building owners need to consider new approaches in the design, construction, and commissioning phases of their building’s ventilation system. One way is to make outdoor air intakes inaccessible. Many times intakes are located in obvious or easy-to-access areas, such as on the exterior ground level, in sidewalks, or on unprotected rooftops. Protecting intakes and associated ductwork and keeping these access points locked and connected into the building’s alarm system could help prevent this type of activity.Filters can be installed to capture harmful substances introduced into a system. It is crucial to determine what materials attest the greatest risk for a building in order to determine if filtration is needed more for chemical or biological particles. For biological needs, HEPA filters are best for filtering particles, while activated carbon filters effectively latch onto harmful chemical materials.Also of equal importance is employee screening. Conducting background checks for all maintenance personnel, particularly ones who have full-building access, is a good way to keep tabs on who’s in and out of your facility. Other practical defenses include installing motion detectors and security cameras on rooftops, in HVAC rooms, and equipment areas where unauthorized persons might attempt to gain access to your building’s lifeline.Lastly, the ongoing maintenance of all installed equipment and security measures is very important. A building with the best equipment and filters is useless if security monitoring and filter replacement are neglected.Up until a few months ago, advanced technology for detecting and filtering hazardous contaminants was primarily the domain of the defense industry. However, the importance of this issue has triggered a surge of commercial development, so the future promises to bring more affordable and effective products to facilities managers looking to improve the security of environmental systems within their buildings.James J. Sadler is vice president at Comfort Systems USA’s Business Solutions Group. Houston-based Comfort Systems USA (www.comfortsystemsusa.com) is the nation’s premier provider of business solutions addressing workplace comfort, environment, processes, and energy services.