daverea.com

Why is it that people think that when fire alarms go off, sprinklers also go off?! I can’t think of any reason for this popular misconception other than movies, where fire sprinklers seem to be able to trip themselves as soon as the alarm goes off.

Lets get this straight: fire sprinklers work by using a small wax or alcohol-filled glass bead to hold back the pressure of the water in the sprinkler pipes. If the temperature around the sprinkler head gets hot enough (usually 120-140°F), the wax melts or the alcohol boils and breaks the bead, allowing the water to flow.

The only way fire alarms and sprinkler activations happen simultaneously is if there is a water flow sensor in the sprinkler line, which trips the alarm after a sprinkler head has opened.

There now – that makes a lot more sense now, doesn’t it?

[More Germany stuff is coming! I'm feeling the jetlag right now, since it's about 3AM in Germany...]