The difference between a Quick Response Sprinkler Head (QRS) and a Standard Sprinkler Head is their thermal sensitivity. That is, a QRS head will generally activate slightly quicker in a fire than a standard head.
All new health care facilities, assisted living facilities and residential occupancies are required to install QRS heads. Likewise, if you add an addition or do a major renovation, i.e. change partitions in an entire smoke compartment or floor, you would be required to install QRS heads. The cost of installing QRS heads is comparable to the cost of installing standard heads.
Where there appears to be some confusion is when a few existing standard sprinkler heads are replaced or when there is a renovation of a small area containing standard sprinkler heads. The following are extracts from the 1999 edition Standard for the Installation of Sprinkler Systems (NFPA 13). The 1999 edition of NFPA 13 is the applicable edition for the 2000 Life Safety Code.
Extract from NFPA 13, 1999 edition, Standard for the Installation of Sprinkler Systems
5-3.1.5 Thermal Sensitivity
5-3.1.5.1
Sprinklers in light hazard occupancies shall be of the quick-response type as
defined in 1-4.5.2
Exception No. 1 Residential sprinklers shall be permitted in accordance with 5-4.5.
Exception No. 2 For modifications or additions to existing system equipped
with standard response sprinklers, standard response sprinklers shall be
permitted to be used.
Exception No. 3 When individual standard response sprinklers are replaced
in existing systems, standard response sprinklers shall be permitted to be used.
5-3.1.5.2
When existing light hazard systems are converted to use quick-response or residential sprinklers, all sprinklers in a compartmented space shall be changed.
1-4.2 General Definitions
Compartment. A space completely enclosed by walls and a ceiling. The compartment enclosure is permitted to have openings to an adjoining space if the openings have a minimum lintel depth of 8 in. (203 mm) from the ceiling.
Section 5-3.1.5.1 states that in all light hazard occupancies, which include healthcare, assisted living and residential occupancies, QRS heads must be installed and then it contains three exceptions.
Exception No. 1 states that where residential sprinklers are permitted, residential sprinklers are deemed equivalent to QRS heads and can be used.
Exception No. 2 states that where there are modifications or additions to existing sprinkler systems using standard sprinkler heads, standard sprinkler heads are permitted to be used in lieu of QRS heads. For example, if you modify an area in your existing building that had standard sprinkler heads and you had to relocate or add sprinkler heads, you could use standard heads in lieu of QRS heads.
Exception No. 3 states that if you have to replace existing standard sprinkler heads, such as old or defective existing standard sprinkler heads, they could be replaced with new standard sprinkler heads in lieu of QRS heads.
Section 5-3.1.5.2 states that if you replace standard sprinkler heads in an existing building with QRS heads, you must replace all the heads in a compartmented space with QRS heads. In other words you can not mix sprinkler heads of different thermal sensitivities in the same compartmented space. Please note that a “compartmented space” does not mean a “smoke compartment.” Unfortunately, the Life Safety Code uses the term compartment differently than the Sprinkler Standard (NFPA 13). See Section 1-4.2 above. NFPA 13 defines a compartmented area as any space enclosed by walls and a ceiling. In common English, that is a room. Section 1-4.2 goes on to state that a compartmented area can have openings to an adjoining space if the openings have a minimum lintel depth of 8 inches from the ceiling. A lintel is a partial wall from the ceiling over a doorway without a door or an archway. For example, this could be a lounge or dining room with no door that is open to the corridor.
It is common for surveyors to misinterpret the term “compartmented space” in Section 5-3.1.5.2 to mean a smoke compartment. This usually happens when the surveyor does not go to Section 1-4.2 and read the definition of compartmented space in NFPA 13.