In general, turning on an air conditioner should not cause a fire sprinkler to go off in an adjacent apartment, assuming the air conditioning system is properly installed and maintained. Fire sprinkler systems are designed to respond to heat, not changes in humidity or temperature from air conditioning units.
Fire sprinklers are heat-activated, and each sprinkler head has a heat-sensitive element. They are designed to activate individually when the surrounding temperature reaches a specific threshold, usually around 135-165°F (57-74°C). Therefore, unless there is an actual fire in the vicinity of the sprinkler head or a significant heat source close to it, the sprinkler should not go off.
However, it's essential to emphasize that poorly installed or maintained fire sprinkler systems might malfunction and activate without a real fire emergency. Leaks, excessive corrosion, physical damage, or other issues with the sprinkler system could potentially cause false activations. In such cases, unrelated activities like using an air conditioner could trigger the faulty sprinkler.
To minimize the risk of false activations, building owners and occupants should ensure that fire sprinkler systems are installed, inspected, and maintained regularly by qualified professionals following relevant safety codes and regulations. If you ever encounter a fire sprinkler activation that appears unrelated to any fire or heat source, it's crucial to notify the building management or relevant authorities to investigate and address the issue promptly.