Be patient: The case for emergency venting windows in hospital rooms

Emergency venting windows, no longer a hospital code requirement except in veterans’ hospitals, will soon receive encouragement from the American Architectural Manufacturers Association of Schaumburg, Ill.

This summer, the AAMA will publish an advisory brochure for architects and health-care facility managers on emergency venting in patient rooms. The AAMA’s booklet, tentatively titled Planning for Patient Safety, Operable Windows in Health Care Facilities, addresses recent code changes that affect architectural design criteria in these facilities. The American Institute of Architects 2001 Guidelines for Design and Construction of Hospital and Health Care Facilities, and the National Fire Protection Association 2000 Life Safety Code Handbook, both eliminated requirements for operating windows to provide emergency ventilation in case of fire.

“The AAMA brochure, on the other hand, advises architects to consider project-specific conditions and considerations that tend to favor venting windows for emergency smoke removal,” says Steve Fronek, vice president of Wausau Windows and Wall Systems in Wausau, Wis. Fronek serves on the AAMA task group that penned the advisory document. 

Task force members find it difficult to prescribe whether operable or fixed windows are the appropriate choice for all hospital applications. However, they conclude that a balanced assessment of operable windows versus break-out fixed glazing or mechanical emergency ventilation is in the best interest of building teams, owners, staffs, occupants and local protective services in a hospital environment.

Fronek and other AAMA members say that in the absence of operable windows, the architect should pay attention to mechanical system options including smoke dampers and engineered smoke control. They suspect that while mechanical smoke-control systems can be effective in areas away from fires, rooms near the fires tend to experience a more pressing need for venting windows to relieve smoke in the immediate area. Unlike venting windows, mechanical smoke-control systems are more prone to malfunction.

Comparing costs

Wausau and other AAMA member companies manufacture fixed and operable windows suitable for health-care facilities. According to the AAMA draft document reviewed by Glass Magazine, “An operable side-hinged in-swing casement vent at every third lite (typically integrating internal Venetian blinds) usually adds about 10 percent to the average installed cost of a fixed strip window system of comparable performance features.” This added cost needs to be weighed against the cost of an alternative engineered smoke-control system, the draft says, recognizing that operable windows offer more benefits than just those related to fire safety.

Breaking fixed windows

The AAMA booklet draft describes problems resulting from breaking glass during hospital emergencies. Citing research by the National Fire Protection Association of Quincy, Mass., AAMA task force members write, “Fixed glass could be broken out in case of emergency for ventilation in typical patient rooms. While professional emergency responders, with special tools and training, may meet fewer challenges when attempting this, it is typically a member of the nursing staff who is first on the scene and may have difficulty breaking the glass in commercial windows.”

The task force members also list several problems with breaking out fixed windows:

•   For structural integrity, 1⁄4-inch or thicker glass is almost always specified for nonresidential applications. Even annealed quarter-inch glass will be difficult to break without a heavy object or tool with a sharp, tough edge, not always readily at hand. Panic, confusion, integral Venetian blinds, window coverings and reduced visibility in smoky rooms add difficulty.

•   AAMA task force members recognize injury hazards may exist when glass is broken out of a window.

•   On impact, standard annealed and heat-strength-ened glass lites break into large fragments that may remain in the openings, and the sharp edges pose a serious hazard to people on the inside and outside.

•   Fully tempered safety glass is even more difficult to break since it is at least four times as strong as annealed glass, although it does shatter into small, relatively harmless fragments. If the force of a blunt object fails to break tempered glass, a sharp pointed instrument or object is typically effective.

•   In some cases, AAMA officials say, special glass types such as acoustical glass, hurricane impact-resistant glass, psychiatric glass or polycarbonate are required and will present an effectively impenetrable barrier to occupants and staff. In these cases, glass breakage cannot be expected and emergency ventilation must be accommodated in the building design.

•   In some instances involving differential atmospheric pressure, task force members note that the introduction of added oxygen from an open window could actually make a small fire more difficult to contain. Since operable windows can be closed, the flow of oxygen exacerbating the fire can be stopped.

Furthermore, the AAMA brochure draft previewed by Glass Magazine also says that architectural framing systems require specialized knowledge and tools to deglaze, and, in most cases, cured sealants must be cut. While complete glass removal might appear to be a preferred alternative to glass breakage, it is simply not realistic in the task force’s opinion.

To compound problems associated with hospital emergencies, responders are said to find evacuation impractical. Recognizing that patients’ mobility can be limited, the NFPA 2000 [building code] states, “Unlike most other buildings and use groups addressed by the code, the least desirable emergency action in a health-care occupancy is the wholesale relocation and evacuation of patients. For this reason, a defend-in-place strategy is used. During a fire, the emergency evacuation of patients in a health-care facility is an inefficient, time-consuming process. Thus, the practical issues addressed above may seriously affect the ability of the patients and staff nearest to the fire to remain unaffected until help arrives, the task force members conclude.

Other benefits to operable windows

Design professionals should also consider the following benefits before relying on broken glass to provide emergency ventilation.

Natural ventilation and daylighting: While primarily intended for emergency use, patients and staff may desire operable hospital windows for natural ventilation. Nasty spills or smells may be quickly aired; power or equipment failure may temporarily disable fans; or a breath of fresh air on a pleasant day may simply be what the doctor ordered. In fact, the American Institute of Architects’ 2001 Guidelines for Design and Construction of Hospital and Health Care Facilities, paragraph A7.2.A3, states, “Windows are important for the psychological well-being of many patients, as well as for meeting fire-safety code requirements.”

Savings on window cleaning and building energy costs: Side-hinged in-swing, vertically pivoted, top-hinged in-swing and tilt-sash double-hung windows are designed so maintenance personnel can clean the outside glass surface from the interior. This ease of maintenance improves building appearance and staff safety, and represents a life-cycle cost savings.

Energy savings: In many parts of the United States, natural ventilation offers a seasonal opportunity for air-conditioning energy savings if included as part of the utility design. Recognizing sustainable design benefits, the U.S. Green Building Council’s Leadership in Energy and Environmental Design Rating System awards points for operable windows in the ventilation effectiveness and controllability of systems credit categories.

Alternatives to operable windows

Smoke dampers remain the first defense against the spread of smoke from room to room, AAMA task force members say. 

In some code jurisdictions, including Massachusetts and Florida, complex engineered smoke-control systems may be used instead of operable windows.

The NFPA building code requires that such smoke-control systems be tested periodically and designed to operate during power outages or equipment failures. In the absence of operable windows, designers must pay attention to special mechanical requirements and assess the incremental costs involved in these systems, the task force members emphasize.

Windows are expected to meet a variety of objectives in building projects, such as lighting, ventilation, aesthetics, security, building-envelope protection, thermal performance and emergency escape. Health-care facilities, including hospitals, require additional attention considering the vulnerabilities of bed-ridden patients  during emergencies.

For copies of the soon-to-be published booklet, visit www.aamanet.org.