When fire protection is required for a building that is not, or cannot be sufficiently heated, the right type of suppression system is of paramount importance to avoid freeze-ups and burst pipes.
In the past, one of the most popular choices of sprinkler systems for areas that are subject to cold weather was an Antifreeze Sprinkler System. These are installed just like any other sprinkler system, but the piping system is filled with a combination of water and a pre-mixed solution (containing propylene glycol or glycerin) that prevents the water from freezing. These systems are often called Glycol Systems.
AFTER SEVERAL YEARS OF TESTING, THE FIRE PROTECTION RESEARCH FOUNDATION FOUND THAT IMPROPERLY BALANCED PROPYLENE GLYCOL ANTIFREEZE SOLUTIONS CAN IGNITE WHEN INTRODUCED ONTO A FIRE, TEMPORARILY INCREASING THE FIRE SIZE UNTIL SUFFICIENT WATER IS DISCHARGED.
National Fire Protection Association (NFPA) 13, 13R, and 13D, updated their standards which requires the use of listed antifreeze solutions that contain a lower percentage of glycol in new antifreeze systems as of September 30, 2012 - with existing systems mandated to meet this requirement by 2022.
(source: NFPA - Current Requirements for Sprinkler Systems Containing Antifreeze)
In the 2014 edition of NFPA 25, all antifreeze systems installed after September 30, 2012, are assumed to meet the minimum requirements. For older systems, section 5.3.4 requires the antifreeze solution to be tested to ensure that it is listed as an approved solution. A listed antifreeze solution was not available until 2019.
You have a number of options available to you depending on the antifreeze in your system, the environment and the overall fire protection requirements for your building(s).
If the concentration is too low or too high, the system must be emptied and replaced with an acceptable listed solution.
If the type of antifreeze in your system is no longer permitted, the entire system must be drained and replaced with an approved listed solution.
Antifreeze solutions currently on the market are approved for environments up to -30 degrees Celsius. If the new approved listed solution is not sufficient to prevent your system from freezing, alternative methods of keeping the pipe from freezing must be implemented.
Heat-tracing could be added for buildings that are close to the freezing threshold.
Insulate and heat areas to ensure the internal temperature remains above freezing at all times.
Dry-pipe sprinkler system should be installed for buildings that cannot guarantee above freezing temperatures at all times
In these cases, Classic Fire + Life Safety can perform a thorough risk assessment of your system that takes into consideration all relevant factors to ensure that you and your building(s) are fire safe.
