Work Together The Firestop Contractors International Assn. (FCIA) was saddened to hear about the loss of life at the Cook County administration building in Chicago recently. FCIA is not part of the investigation and has seen no official report on the causes for the loss of life. However, we've all heard and read in the media that deaths occurred due to smoke inhalation in stairwells while pe...
The Firestop Contractors International Assn. (FCIA) was saddened to hear about the loss of life at the Cook County administration building in Chicago recently.
FCIA is not part of the investigation and has seen no official report on the causes for the loss of life. However, we've all heard and read in the media that deaths occurred due to smoke inhalation in stairwells while people were trying to escape the blaze.
Stairwells are usually known as "havens of safety" in the fire-protection industry. In this case, the stairwell was a death trap as it became smoke-filled for reasons yet unknown, and had locked doors for security purposes, causing entrapment.
As a response to this tragedy, there has been a loud cry for a single solution to prevent future loss of life. Proposals have ranged from the installation of sprinklers to having building occupants wear a single-use oxygen mask to escape safely from fire and smoke.
Although a miracle cure would be great, the reality is there is no one thing that could have prevented the loss of life. But there are some fire-protection features the fire investigation panel should consider.
Of course, if the building was equipped with sprinklers, the fire might have been limited to the room of origin, although that might not necessarily have prevented the smoke from traveling. But if the fire's room of origin was also outfitted with a fire-resistance-rated assembly with appropriate fire doors, fire and smoke dampers and firestopping systems, the fire and smoke may not have traveled from the room (a storage room) to the rest of the building.
Furthermore, if pipe, cable and other room and floor penetrations were properly firestopped and had air leakage ratings, the smoke from the fire may not have traveled from the room of origin.
As a forensic analysis of this tragedy continues, we shouldn't limit the conclusion to a single solution. Sprinklers, while an effective way to limit the spread of fire, can create smoke. Passive fire protection features can limit the spread of both fire and smoke. As seat belts and air bags are most effective when used together, so are active and passive fire-protection systems.
Dr. Gene Corley, team leader for the World Trade Center Building Performance Study, made this point in a recent Chicago Sun-Times article. "Fire safety cannot be an 'either or' proposition," he said. "Buildings for which sprinklers are appropriate should also have fire-resistant construction for better fire protection. Anything less puts occupants and emergency responders at risk."
Maybe our call to action as a result of this tragedy should be "Why not have both?"
Bill McHugh, Executive Director, FCIA, Wheaton, Ill.
Plastic Diffuser Comments Challenged
I was concerned by statements made about plastic diffusers in the story "Fire Down Below" (CSE 09/03 p. 55).
In that article, Gus Faris, director of engineering at Nailor Industries, is quoted as saying, "No plastic can pass… the 25/50 flame-spread index testing unless extreme amounts of graphite are injected into the plastic."
According to Faris, "Injecting the required amount of graphite would cause the plastic to become brittle, and then it would not be suitable for use in a floor diffuser."
That statement is completely false. The article further states that "some code officials overlook the requirement and allow plastic to be used…while others are stricter and require metal diffusers."
We would like to believe these comments were not motivated by the fact that Nailor Industries currently does not offer an NFPA 90A-approved plastic floor diffuser.
In reality, all the NFPA committee did was pass a motion extending the same exceptions to floor plenums that currently exist for ceiling cavity plenums. It had nothing to do with the inability of plastics to meet the 25/50 flame spread/smoke tests.
David Gau, Vice President, Titus, Richardson, Texas
Gus Faris replies
With all due respect, and with no intention to drive any agenda, what NFPA did was make a major change to their standard.
The 1999 edition, paragraph 2-3.10.6, Exception No. 4, refers readers to paragraph 2-3.3. Paragraph 2-3.3.1 and 2-3.3.2 both require a Smoke Developed Index of 50 and a Flame Spread Index of 25. The definitions of both indices refer to NFPA 255 or UL 723. There is no further discussion in the 1999 version. The 2002 edition allows NFPA 262 or UL 2043 to be used for the 25/50 test. This new test is the same one used for testing wire insulation, cables and optical fiber cables. The test proves the 25/50—not as done in NFPA 255, but as "having a maximum peak optical density of 0.5 or less, and average optical density of 0.15 or less (this is the smoke spread of 50), and a maximum flame spread distance of 1.5 meters or less when tested in accordance with NFPA 262."
My comment was that the 25/50 rating was not achievable under NFPA 255. The plastics people [at Titus] tell me that the only way to pass the 255 test with plastic products was to add lots of graphite.
As far as the comment about local authorities overlooking the 25/50 rating, for some time it has been known that plastics did not pass the 255 test. In fact, at least two of our competitors have been touting their metal alternatives for this reason. Yet there are literally tens of thousands of plastic diffusers installed all around the country and the world, for that matter. Chicago, Houston, Memphis and San Francisco, for example, allow plastic. But some fire marshals—Pennsylvania, Denver and its three surrounding counties, Washington D.C. and Omaha—have not allowed plastic.
The use of NFPA 262 may make these areas available, and they may not. It is a local authority-having-jurisdiction issue. That, too, is defined in NFPA 90A.
Regarding "A Green State of Mind" ( CSE 10/03 p. 52) and determining what a green product is, ASTM has developed a standard for product analysis: E2129-01, "Standard Practice for Data Collection for Sustainability Assessment of Building Products."
Among other elements, it addresses several items that LEED has yet to include. It is also a collection of the documents that outline the testing methods for things like fly ash, silica fume, ASHRAE, etc.
This is a good place to start to understand the important elements of judging products, and it should be communicated to the construction community. It may be requested or required in the future by end users or architects trying to build LEED-certified buildings.
Jeff Arnim, Tarkett Commercial, Houston, Texas
More Data Required
I continue to be amazed at the lack of full disclosure in articles dealing with LEED certification on projects.
In the article "Solar Roofing: Seamless Integration of Architecture and Engineering" ( CSE 10/03 p. 59), the author goes to great length to describe the "benefits" of the photovoltaic panels installed on the project. They are rated at 10 kW and provide an average of 35,000 kWh per year for three years at an annual savings of $2,500 per year. There are options available to sell excess power back to the utility when the system is "generating maximum power for an unoccupied building." All of this is great spin on the topic. However, it doesn't provide the answers to the questions that are generated by those of us who are seeking options to meet the specific requirements of our owners and the LEED process.
Some of these questions are:
What is the installed cost of the photovoltaics, including all of the metering options?
What is the payback in an economic cost analysis?
How much power has been sold back to the utility company?
Is this included in the $2,500 per year savings?
At 35,000 kWh per year savings, what percentage of the total electrical power usage does this represent?
What is the cost impact (if any) of designing the roof at an angle of 42°?
Until this type of information is provided, the use of these systems remains a novelty aimed at getting points from the LEED process, not as a viable, economically based engineering decision. After all, the USGBC has made claims that compliance with LEED process will provide a less costly building to construct and operate. Let's see the data.
Raymond F. Parham, P.E., Affiliated Engineers, Gainesville, Fla.
Note: Don Nolte, P.E., of Progressive AE, the article's author, will respond in next month's Letters.