ENERGY-EFFICIENT WINDOWS IN MULTIPLE DWELLINGS

ENERGY-EFFICIENT WINDOWS IN MULTIPLE DWELLINGS

TRAINING NOTEBOOK

• evidence of fire on the third floor.

This is the first in a series of articles contributed by members of the Fire Chiefs Association of the City of New York Fire Department.

Conditions that you can expect when encountering energy-efficient windows (EEWs, also known as thermal-pane or double-pane windows) in a fire environment are among the most severe recorded in recent firefighting experience.

Consider these recent fire incidents in New’ York City:

• A six-story, ordinary-constructed multiple dwelling with EEWs. Fire on the fifth floor, reports of people trapped on the sixth floor. Delay in operations due to a long hose stretch around an elevator shaft. There was a sudden explosion with a ball of fire on the sixth floor. A firefighter who was just entering the apartment at the time of the explosion was severely burned. A lieutenant was trapped at a window and was rescued via a lifesaving rope. A chair was blown out of a front window and landed in the street 30 to 40 feet from the fire building.
• A five-story, ordinary-constructed multiple dwelling with EEWs. Fire on the second floor front, high heat and heavy’ smoke condition in the apartment directly above the fire, medium smoke condition in the adjacent apartment on the floor above, and no
• visible indication of fire in the building to the first-arriving units. While conducting the primary search in the apartment directly above the fire, the apartment lit up, trapping two firefighters who had to be removed via aerial ladder. In the adjacent apartment on the floor above the fire there was an explosion that blew down a partition wall in the bedroom, blew the upper and lower sections of the window assembly out of the frame, and trapped three firefighters, who had to be removed via a portable ladder.
• A five-story, ordinary-constructed multiple dwelling with EEWs. Heavy smoke condition pushing out of all top-floor front windows and cornice. Determination of the exact location of the fire was difficult due to heavy smoke condition in the public halls from the second through the fifth floors. The fire apartment was on the fifth floor, exposure #2 side of the fire building, but an extremely heavy smoke condition was encountered in a fourth-floor apartment on the exposure #4 side of the building. Several household pets, overcome by smoke, were discovered on the top floor on the exposure #4 side of the building.
• A six-story, ordinary-constructed multiple dwelling with EEWs. Heavy smoke condition showing out of five windows on the fourth floor. Upon entry into the building the location of the fire was determined to be the third floor. While the windows of the fire apartment were tightly closed, the windows of the apartment on the floor above were slightly open. The smoke that was pushed into the floors above began to show at the fourthfloor windows before there was any
• A five-story, ordinary-constructed multiple dwelling with EEWs. A corner buiding with a heavy smoke condition visible pushing out of the entire cornice. There was no sign of smoke or fire at any window. Fire was located in a top-floor apartment in the front of the building. A delay in the positioning of aerial apparatus and venting operations resulted.
• A six-story, ordinary-constructed multiple dwelling with EEWs. An adjacent three-story, wood-frame building was fully involved in fire on arrival. The EEWs in the exposed six-story building did not fail even though they were exposed to a large volume of fire for several minutes. Fire extension to the interior of the multiple dwelling was prevented.
• A five-story, ordinary-constructed multiple dwelling with EEWs. Fire on the fifth floor venting out of three windows and also into the public hall. The remaining windows did not fail under this very high heat condition and were vented with difficulty. The advance of the engine company was negligible until all the windows were vented.

DESCRIPTION

• EEWs are found in both new and renovated buildings of Type I (fireresistive), Type III (exterior protected combustible—ordinary construction), and Type V (wood-frame) construction as described in the Fire Protection Handbook, 16th edition, published by the NFPA.
• They’re made to the exact size of the previous window opening.
• They’re double panes of glass with an air space in between.

ENERGY-EFFICIENT WINDOWS

• They’re full panes of glass, top and bottom (also known as “one over one”).
• The frame is constructed of vinyl or metal, usually aluminum alloy.
• They have full or half screens that may be raised or lowered as the weather dictates.
• They have a metal cross piece in the center of the window with a locking device.
• Each section (upper and lower) may be taken out or swung inward for cleaning or replacement.
• They are secured to the window opening by two or three bolts on each side.
• Caulking or insulation is placed around the unit to make for an airtight installation.

PROBLEMS

• Delay in the detection and reporting of fires because of the tight seal and double glass panes.
• Discoloration of the double glass panes from high heat buildup is not readily observable.
• Difficulty in determining the location of the fire from the exterior.
• High heat and smoke buildup in the fire apartment and in the apartment above the fire.
• High potential for flashover or backdraft in the fire apartment and the apartment above.
• Very rapid movement of smoke and toxic gases into the cockloft at top-floor fires; consequently all the apartments on the top floor become heavily charged much more quickly.
• Difficulty in venting from the roof level, the floor above, the fire escape, or the interior due to double glass panes and screen material.
• Reduced time for primary search due to rapid heat buildup and presence of backdraft conditions.
• Difficulty and delay in gaining entry via the exterior due to metal cross piece.
• Severe smoke conditions on the floors above even from a small fire controlled by one hoseline.
• Abnormally high levels of carbon monoxide in situations where the fire is reduced to the smoldering stage.
• Delay in stretching interior lines due to the necessary removal of occupants from upper floors.
• Additional manpower requirements for search and removal operations on the floors above and the control of these forces.
• Additional forcible entry required to secure adequate secondary means of egress.
• Tremendous rise in internal pressure in the fire apartment resulting in a forceful explosion and flash fire when windows are vented by members; this is due to the fact that heat and fire gases are unable to escape or self-vent as in older installations.
• Extremely high heat levels necessary for window failure —much greater than that necessary for ordinary window installations.
• Minor hidden fire extension possible between the frame and original window opening in cases where the new window frame is installed without removal of existing wood trim.

TACTICS

• Communicate the presence of EEWs via department radio and portable radio.
• Transmit second alarm on arrival for a medium-to-heavy fire condition on the lower floors in anticipation of additional manpower needed for search and removal operations on the upper floors.
• Place first hoseline into operation promptly. Before a problem develops, place into operation a second hoseline to back up and protect the first. The second line must have sufficient hose to cover the fire floor and the floor above. Place additional lines into operation as needed.
• Place ladder company apparatus (aerial or tower ladder) to provide maximum venting of the fire area.
• Place portable ladders at fire escapes to provide access for firefighters and egress for occupants.
• Remove both panes of glass and screen material entirely when venting. Striking the window once gener-
• ally will not provide sufficient ventilation. Repeated blows will be required.
• Use specialized tools for venting EEWs from roof level or from the floor above the fire. Remove all of the glass when venting from the floor above. When operating on the floor above the fire, removing an entire window vents that area and also permits greater access for venting the windows below. Great care must be taken when venting in this manner so as not to create an autoexposure problem.
• Place hydraulic forcible entry tools into operation promptly for rapid entry on the fire floor and the floors above.
• Acquire safe means of egress on the floors above the fire before units operating there initiate searches.
• Consider the use of engine company personnel to assist in removal operations from the upper floors balanced against the need for additional hoselines.
• Units on the floors above must constantly monitor the heat conditions on the fire floor and the floor above.
• Assign an additional chief to supervise operations on the floor above the fire.

Recognizing the presence of these windows early in the size-up and announcing this information to the incident commander and all units is crucial to a successful operation. Pay particular attention to older residential buildings in which limited ventilation options already exist because of lack of windows.

Ventilation is the key to resolving the problems that occur with fires in buildings that have EEWs. When possible, exterior ventilation should be performed by use of aerial and tower ladders on the fire floor and the floors above unless it would cause an autoexposure problem. Particular attention should be given to the floor above the fire, both in the apartment directly above and adjacent apartments. Chauffeurs of aerial and tower ladders should place the apparatus where it will provide maximum coverage for venting the fire area. When venting they must be sure to break both panes of glass in both the upper and lower sections of the window. After ventilation is completed they should remain at the turntable and be ready to remove any trapped members. Rooffmen must bring a lifesaving rope to the roof and be alert for conditions that may result in trapped personnel. When the fire is in the rear, the outside vent firefighters will be required to handle the ventilation, which will take considerable effort due to the difficulty in breaking the double panes of glass. Striking the panes with a halligan tool results only in small holes —it requires multiple hits to remove one window completely.

ENERGY-EFFICIENT WINDOWS

Interior ventilation requires a systematic and thorough approach. If conditions permit, no windows should be skipped from the point of entrance into the fire apartment or apartments immediately above the fire. As in exterior ventilation, the firefighter must be certain to vent both panes. Conditions permitting, it’s possible to open the window completely by removing the window sections as would be done for cleaning. This procedure allows for maximum possible ventilation with minimum effort expended and with less damage to the structure.

Always monitor rapid heat buildup and prepare for a rapid withdrawal. As noted previously, flashovers and backdrafts can be extremely powerful in residential structures with EEWs. The heat buildup is so rapid that on two occasions different ladder companies, manned by experienced senior members and operating on the floor above the fire, entered apartments to conduct primary searches, became trapped, and sustained second-degree burns to unprotected areas of the head and neck. They had to be rescued by other firefighters. Interviews with the injured members revealed that when initially entering the apartments they did not observe high heat, but shortly after, heat buildup was very rapid, becoming unbearable after only a brief period of time.

In all of the situations mentioned earlier, the involved structures were of ordinary construction and thermal pane replacement windows were installed. Although these windows have been installed in buildings of Class I construction, we have neither witnessed nor been made aware of any unusual experiences associated with EEWs in these buildings. Generally a high-heat condition is expected in this type of construction. The EEWs will last longer under fire conditions and can be expected to contribute to a greater degree of heat buildup as compared with the older casementtype windows, which tend to fail and vent the fire after a relatively short period of time.

The fact that EEWs maintain their integrity longer than ordinary singlepane windows in a fire environment docs have a positive side: When subjected to a fire from below or from a nearby exposure, the windows will delay fire extension via autoexposure. Also a potential benefit is the construction feature on many models that allows the firefighter to completely remove both the upper and lower sections of glass, thus providing for maximum ventilation and an unrestricted means of egress without damage to the installation.