Enclosures for Emergency Generators

Q: Do emergency power generators have to be located in a room by themselves? We have a generator that is located in a mechanical room which is shared with an air-handler, condensate pumps and other equipment. This generator was installed in the 1970’s, but a consultant told us we had to relocate the generator to a 2-hour room where it can be located by itself.

A: NFPA 110 (1999 edition), section 5-2.1 says the generator must be installed in a separate room with a 2-hour fire rating, and no other equipment is permitted in the room. However, section 1-3 of the same standard says NFPA 110 only applies to new installations and existing systems are not required to conform to the standards, unless the authority having jurisdiction (AHJ) determines that nonconformity presents a distinct hazard to life. If the generator has been installed since the 1970’s and no AHJ has cited you for nonconformity, then I suggest it is safe to assume the AHJs that have inspected your facility do not have a problem with the arrangement. If an AHJ attempts to cite this situation for non-compliance with NFPA 110 (1999 edition) section 5-2.1, then I would make the case that it is not required to since this room was constructed long before NFPA 110 was in existence. NFPA 110 was first adopted in 1984 by NFPA, so it was not part of the Life Safety Code until probably the 1985 edition.  Therefore, it may be assumed it met the standards that were in existence in the 1970’s when the building was constructed.

Automatic Door Operator

Q: We are in the process of installing a door in a 2 hour fire barrier with an automatic door operator and positive latching. The door operator will be activated by two push plates mounted on the wall. In the event of a fire alarm, are we required to drop power to the door operator?

A: To be sure, fire-rated doors with automatic operators must close and latch during the activation of the fire alarm system, according to NFPA 80 (1999 edition), section 2-1.4.2. So, to answer your question: Yes, the power to the automatic operator on the fire-door you proposed would have to be interrupted during a fire alarm. The door must still be permitted to operate manually however, but the power to the automatic operator must be interrupted.

Existing Fire Rated Doors

Q: Do existing fire rated doors (in a 2-hour fire rated barrier) have to have a vision panel (window) in the door?

A: No, I do not believe that they are required to have vision panels, although they are permitted, as long as they are factory installed. Section of the 2000 edition of the Life Safety Code requires door assemblies in fire-rated barriers to comply with NFPA 80 Standard for Fire Doors and Fire Windows (1999 edition). Section 1-7 in NFPA 80 discusses glazing materials in fire doors, which is another name for vision panels, or windows. The standard discusses the requirements that must be followed when glazing materials are installed in fire rated doors, but it does not specify that glazing materials is required in existing fire rated doors. For fire rated door assemblies in new horizontal exits, vision panels are required, according to section of the Life Safety Code.

Fire Rated Walls and Barriers

Q: Are fire rated walls the same thing as fire rated barrier? And are smoke compartment barriers actually fire rated walls?

A: As it has been explained to me, a fire rated wall is used to subdivide a building into separate areas and they extend from an outside wall to another outside wall, and from the floor of the lowest level up through the roof of the highest level. A fire rated wall is structurally self-sufficient and acts as a block in the event a fire develops on one side, to prevent the fire from spreading to the other side. Fire rated walls are specified by building codes, and are not addressed by the Life Safety Code for healthcare occupancies. On the other hand, a fire rated barrier is not a fire rated wall, and are used extensively in healthcare occupancies. A fire rated barrier extends from the floor to the deck above. Examples of a fire rated barrier would be the walls surrounding a hazardous room; a vertical shaft (such as a stairwell or elevator shaft); and a separation between different occupancies or construction types. All opening in fire rated walls and fire rated barriers (such as doors, dampers, access panels, etc.) must be fire rated and equipped with fire rated frames and hardware. To be sure, smoke compartment barriers are not fire rated barriers; however they are similar. The barrier itself is constructed with fire rated materials however the doors in the smoke compartment barriers are not required to be fire rated, nor are they required to have positive latching hardware. They only have to self-close. Smoke compartment barriers are required to extend from the floor to the deck above. Another barrier that you may need to know about are smoke resistant barriers, which have no fire rating, but are required to extend from the floor to the deck above, and resist the passage of smoke. Corridor walls in a non-sprinklered smoke compartment are required to be smoke resistant barriers.

Construction Type Barriers vs. Occupancy Separation Barriers

Q: I read with interest the article Understanding the Importance of Construction Types in the February, 2011 issue of HLSC. The article said a 2-hour fire resistance horizontal barrier is not allowed to separate different construction types, only vertical barriers. Isn’t a 2-hour rated floor assembly permitted to separate different construction types? Isn’t a 2-hour barrier sufficient to distinguish a barrier between different buildings?

A: You may be confusing different purposes for a 2-hour fire resistance rated barrier. Separating different construction types requires a 2-hour vertical barrier. Separating different occupancies that involves healthcare requires a 2-hour vertical and/or horizontal barrier. Section 8.2.1 of the 2000 edition of the Life Safety Code® (LSC) only permits vertical 2-hour fire resistance rated separations between different construction types, and does not permit horizontal barriers. The reason behind this requirement is very logical. The requirement for the fire resistance rating of construction types is based on the estimated time it takes to evacuate the building in the event of a fire. Most multi-story hospitals are required to be at least Type II (222) construction which allows for the extra time it would take to evacuate non-ambulatory patients from the building. If a lower floor was permitted to be less that Type II (222) construction, even if it were separated by a 2-hour fire rated floor assembly, a fire on the lower floor which has less fire resistance rating on its structural support members may cause the building to collapse before all of the patients are evacuated. Section does not restrict the 2-hour barrier between different occupancies to either vertical or horizontal, therefore they are both permitted.