Ideally, all sprinkler systems would be properly designed and installed for their environment. Dry sprinkler systems would properly slope in order to drain and wet systems would be properly insulated in areas that drop below 40°F. Unfortunately, the ideal situation isn’t always a reality and you can’t just turn off a fire protection system every time it gets cold to prevent potential freezing problems.
Every year, we find dry pipe systems that are improperly installed and do not drain as a result. Building owners don’t have much control over the slope of their dry pipe systems, but they can make sure the systems are otherwise properly drained before freezing weather arrives. In a wet system, building owners and operators can ensure the pipes remain heated and insulated enough to not freeze.
According to Cold Facts About Freeze-Ups written by Richard Gallagher, to prevent a pipe freezing scenario, building owners and operators should take preparations before cold weather, routine actions during cold weather, and special precautions when a building might be unattended for an extended period of time.
WHAT TO DO BEFORE COLD WEATHER
In wet sprinkler systems:
- Annual servicing of your heating systems will help to ensure dependability when the temperature drops. As it becomes colder, heating systems play an important role in preventing wet system freeze failures.
- Check all piping to verify insulation is intact.
- Make sure there are no major leaks or blocks (like broken ventilation) in building openings.
- Verify system performance and monitoring.
In dry sprinkler systems:
- Check air sources/air pressure.
- Check and operate low point drains to ensure there is no residual water in the system piping.
- Test low temperature and system air pressure monitoring devices.
Harrington Group strongly recommends that all work on fire sprinkler systems be performed by trained, experienced individuals who are employed by a professional fire protection construction company.
WHAT TO DO DURING COLD WEATHER
In the cold building spaces where wet sprinkler systems are normally located, like above the ceiling, you can install thermometers that can be checked remotely. If wet system freezing is a major concern, you should consider replacing it with a dry system. A dry system is less likely to freeze, but they still require monitoring and maintenance.
During extended periods of cold weather or vacancy, building owners should safely increase heat in all building spaces and turn off energy savings settings. Extended idle periods occur when building occupants leave for a long weekend or holiday. During these periods, building owners need to make sure suitable means of heat loss detection are maintained. Where building temperatures are detected at or below 40°F, prompt action by the building owner is needed. Every sprinkler system has a control valve. Building operators should know where the sprinkler valves are in order to turn them off in the event of a system failure.
Freezing of water-based fire protection systems is avoidable. Many sprinkler freeze failures occur due to inadequate building heat. Building owners who actively monitor and maintain building heat will help to reduce many fire system freeze failure impairments.