The last thing anyone wants during an event is for sprinklers to go off unexpectedly—soaking everything in sight—just because you turned on a fog machine.
The good news? A fog machine is very unlikely to set off sprinklers.
Why Fog Machines Don’t Trigger Sprinkler Systems
Sprinkler systems are different from smoke alarms in how they detect potential fire. Sprinklers are typically heat-activated, not smoke- or particle-activated. Here’s a breakdown of how they work:
- Heat-sensitive bulbs: Most modern sprinkler systems are triggered by a glass bulb filled with liquid that expands when exposed to high heat. When the temperature reaches a critical point (usually around 135–165°F or 57–74°C), the liquid bursts the bulb, releasing water.
- Heat threshold: Fog machines only produce a mist-like vapor that’s far below the temperature required to activate the heat-sensitive bulbs in the sprinkler system. Unless your fog machine is creating very hot fog, it won’t trigger sprinklers.
Types of Sprinkler Systems and Fog Machines
- Wet sprinkler systems: These systems contain water in the pipes, ready to be released when a heat-sensitive bulb bursts. Fog won’t raise the temperature enough to activate them.
- Dry sprinkler systems: These hold air or nitrogen in the pipes and only release water when the sprinkler heads are triggered by heat. Again, fog is not hot enough to activate these.
In contrast to smoke detectors, fog particles don’t pose a risk to these sprinkler systems since they’re not designed to detect smoke or mist but instead respond to temperature.
Precautions You Should Still Take
Even though fog machines aren’t a direct risk to sprinklers, it’s always a good idea to follow these steps to ensure a safe environment:
- Check with venue staff: Some venues have highly sensitive fire safety systems, and even though fog shouldn’t affect sprinklers, it’s best to confirm with the venue about their specific setup.
- Use controlled fog output: Keep the fog machine’s settings moderate, especially in confined spaces, to prevent excessive fog buildup that could concern safety personnel or guests.
- Test ahead of time: If possible, run a test of your fog machine to see how it affects the space and whether it triggers any alarms (though again, sprinklers won’t be an issue).
Final Thoughts
In almost all cases, fog machines won’t trigger sprinklers, since these systems rely on heat, not smoke or particles. So, feel confident in using your fog machine—just keep in mind other fire safety protocols, like smoke detectors, as those are more likely to cause disruptions!