Owners with buildings in freeze-prone areas know how important it is to be ready for winter, from preparing commercial properties to prepping for outdoor snow removal. Being winter-ready can help minimize surprises in the event of an early freeze and may ultimately save money by reducing unplanned work.
An important part of the winterization process for buildings with fire sprinkler systems will be readying sprinklers for cold weather. These lifesaving and property-protecting systems must be kept functional during freezing conditions to work. Here are some important considerations for winterizing fire sprinkler systems and some benefits of having a clear plan.
Tip 1: Confirm Your Sprinkler System Type to Make Appropriate Winterization Plans
Proper winterization starts by knowing your system type: Is it a “dry” or a “wet” system? These system designs differ slightly in winterization options and requirements.
A dry system design pressurizes the sprinkler pipes with a gas (usually air or nitrogen) instead of water, keeping the alarm valve to the water supply closed. The air pressure in the system drops if the sprinkler head activates, allowing the alarm valve to open and release the water to the sprinkler heads. Because a dry system is designed to keep water away from the sprinkler heads, proper winterization requires an installation, testing, and maintenance (ITM) contractor to confirm that the system’s components are keeping water away from the sprinkler heads and piping and that the pressure in the pipes is within the safe operating range.
A wet system pressurizes the pipes with water all the way to the sprinkler heads. A wet system installed in freezing areas of a building requires different winterization practices, which can vary based on budgets, piping materials and practicality. These options include:
- Insulation: Often lower cost and easy to install, but material compatibility must be carefully considered, and additional freeze protection may still be necessary.
- Heat tracing: Usually a much higher cost and requires careful compliance with all applicable codes and manufacturer instructions for wiring and pipes, but can provide very reliable freeze protection.
- Agency-listed antifreeze: Factory-premixed antifreeze products are commercially available and have earned UL or similar approval for safety and performance. A UL 2901 listing means the antifreeze reduces corrosion by a certain percentage, a valuable feature for water-filled pipes. Correctly installed, maintained and tested, this option is often the most economical when all factors are considered. Because listed antifreeze has different installation and maintenance practices from site-mixed antifreezes, contractors may wish to contact antifreeze manufacturers for additional guidance.
Tip 2: Treat Winterization Practices as Part of Regular Maintenance
A regular regret among building owners is waiting too long to start winterizing. Maybe an early freeze causes pipes to burst, or your contractor’s schedule is now so full that he can’t come winterize your property until mid-January, or any one of many other “maybes.” Waiting until the first freeze approaches means rushing, which is a recipe for risk.
Instead, winterization should be treated as part of ongoing sprinkler system maintenance. Keeping a regular maintenance schedule with your contractor on the calendar can help reduce unplanned downtime by catching problems before they turn into emergencies. It also minimizes the risks of “seasonal surprises” like burst pipes.
How does this look in practice? A dry system, for example, requires an annual comprehensive inspection and a tri-annual “full flow trip test.” But every week—or every day if possible—a trained member of your staff should be checking pressure gauges to make sure they read within range. Both the yearly comprehensive inspection, which should occur before winter, and these weekly or daily inspections are critical to preventive maintenance. Wet systems also require an annual inspection: NFPA 25 changes after September 2022 mean that Authorities Having Jurisdiction (AHJs) must confirm that a wet system has agency-listed antifreeze correctly installed without dilution. If completed before the winterization rush, building owners can take care of necessary retrofits, such as a system flush or adding an expansion tank, before the first freeze.
Follow the Code to Beat the Cold
No matter what type of system you have in place, complete compliance with all local, state and federal codes and meticulously following all products’ installation manuals are essential to success. This helps protect lives and property. Doing things the right way, rather than defaulting to “how it’s always been done,” may also help save money by cutting avoidable waste and maximizing the service life of a sprinkler system and the products that support it.
By winterizing appropriately for your dry hydraulic design or antifreeze loop fire sprinkler system and by keeping a regular schedule of routine maintenance practices, you set your building up for success all year long.
