HVAC Burglar Bars


Most discussions in the fire/rescue community on the hazards of burglar bars focus on the danger they present to building occupants and firefighters who are trapped by fire and smoke conditions and unable to exit through a window or doorway.

However, because of tough economic times and innovative thinking, your local criminals may now present a different kind of challenge. When conventional breaking and entry efforts fail or are too risky, some burglars will now attempt rooftop entry through ductwork. Numerous videos show thieves who, on entering a building through the roof and ceiling, got stuck and were unable to exit the building.

Heating, ventilation, and air-conditioning (HVAC) specifications for many businesses and other tenants moving into remodeled buildings call for increased security measures, such as ductwork sleeves with burglar bars. Security standards often specify that this security feature be included in the ductwork systems running from exterior rooftops into the building interior. Although this feature is commonly found in government buildings with enhanced security requirements, many businesses now include it to keep unwanted visitors out after business hours.

Contractors may install the crossbar configuration in several locations throughout the main portions of the trunked ductwork. The most common location is just before the metal ducting entering into the building rooftop, commonly referred to as the “roof curb.” This will include both the supply and return sides of the HVAC system. The assembly itself is typically manufactured with ½-inch welded steel bars, with the option to upgrade up to ¾-inch steel. HVAC personnel can now insert ductwork sleeves with burglar bars into older systems during routine maintenance visits for building owners who have already experienced a break-in or just want increased security (photo 1).

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(1) A 48- × 24-inch HVAC ductwork sleeve, just before installation. (Photo by author.)

In 2002, the Fort Belvoir Fire Department in Fairfax County, Virginia, responded to an incident to assist local law enforcement. We provided automatic aid with our neighboring jurisdiction to assist police units in the extrication of a person reportedly stuck in HVAC ductwork. An unauthorized person became trapped while attempting to burglarize a commercial fast-food restaurant, just outside one of our military installation’s main gates. This individual became trapped while attempting to gain access by entering through the HVAC system from the roof.

A truck company crew was assigned to cover roof operations while an engine company worked inside the building to attempt initial access and obtain a visual of the trapped victim. Interior crews disassembled the ductwork system, eventually exposing the victim’s feet and ankles. This burglar accessed the HVAC system feet first and got stuck while trying to negotiate a 90° turn in the metal duct system. Crews operating on the roof used vegetable oil to provide lubrication (a resource available at this site) and lowered a rope down to the victim. The rooftop crew eventually dislodged the victim and pulled him up vertically.

Personnel began initial treatment for the victim, who had suffered leg and back injuries. They then lowered him from the rooftop in a stokes basket using an aerial ladder. The victim’s treatment continued on the ground, and he was taken into custody by law enforcement. Crews operated with police for about an hour at this event. This incident might have been more complex if the duct system included burglar bars, requiring additional tools and equipment to access the patient.

Burglar bars can be an unexpected obstacle for persons attempting breaking and entering through the building’s ductwork system. Confronting these reinforced steel bars at the end of a long crawl through a maze of sheet metal, a burglar could become stressed, incapacitated, and unable to get turned around to exit. Someone stuck in an HVAC system will likely pose a challenging confined space scenario for fire/rescue personnel. We need to come up with creative ways to extricate such an individual entrapped in ductwork.




Location. Determine, if possible, the exact location of the person or persons in the duct system. Burglars may have accomplices helping them, so expect that more than one person may need extrication.

Physical condition. Does the subject have any injuries? Is he able to move himself toward either end of the ducting—i.e., self-rescue?

Confined space operations.Operating inside any tightly enclosed space with limited entry and egress, especially sheet metal ducting, meets the Occupational Safety and Health Administration’s definition of a confined space. The above-mentioned recommendations should coincide with your department’s local confined space entry and rescue operations response procedures and guidelines. Make sure your unit or company has the necessary capabilities to handle the special operations at hand (i.e., special training, equipment, and personnel). A needs assessment for technical rescue equipment and staffing will determine the need to summon additional resources. Be sure to maintain communications with local law enforcement on-site, and include them on the incident action plan before and during victim removal.




Consider the possibility that the person may have a weapon. Fire/rescue crews may need to request and include tactical (i.e., SWAT) trained police officers to assist during the extrication effort.

During the rescue, advise law enforcement officials to remain in standby mode. Explain that communications should be between only fire/rescue personnel and the subject during the actual rescue. The subject can then concentrate on the rescue efforts at hand and not on the likely arrest afterward. This will also hopefully reduce any anxiety on the criminal’s part and keep that person from trying anything unwise that could endanger himself and rescue crews.

Ensure that law enforcement is ready to apprehend the subject once he is close to exiting either end of the duct system. The individual may begin to struggle with rescue crews and attempt to exit on his own once he realizes he is close to final removal. Police units must be ready for apprehension. Fire/rescue crews must inform law enforcement once the subject is close to egress.

Try to gauge the subject’s mental state. Many thieves who engage in criminal activity may be under the influence of narcotics, alcohol, or both. This will affect the person’s ability to understand and follow instructions. Is the person able to help you help him? Explain to him that if he wants to get out badly enough, he must listen closely to instructions given.

Innovatively desperate criminals will try almost anything to gain access to the desired goods. This is not just limited to HVAC systems. These days, burglars will try any passageway or threshold not designed for occupancy or entry. Your department may find itself assisting police units with subjects stuck in/on rooftops, ceilings, cocklofts, attics, and any other imaginable means of building access.

In a fire department response to unknown odors in buildings, we often expect to find the source to be a dead woodland animal. We shouldn’t rule out the possibility of finding a deceased person.

DANIEL WEDDING is a firefighter with Truck Company 463 at the U.S. Army installation at Fort Belvoir, Virginia, where he has served for more than 10 years. Previously, he served for 12 years as a volunteer firefighter with the Falmouth (VA) Volunteer Fire Department and the Hartwood (VA) Volunteer Fire Department. He is certified by the National Board on Fire Service Professional Qualifications as a safety officer, fire officer III, instructor II, and hazmat technician and maintains technical rescue certifications through the Virginia Department of Fire Programs.


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