A correctly installed heat alarm will reliably trigger Automist Fixed System and should supplement household existing smoke alarms which can provide an additional warning of fire. Heat alarms give an audible warning when the temperature at the alarm reaches 57°C and, unlike conventional smoke alarms, will not be triggered by burning the toast, steam from cooking, or a car's exhaust fumes.
Automist Smartscan Hydra goes further with a double knock alarm. It first needs to be triggered by a ceiling mounted combination alarm (smoke and heat), and then the fire location must be confirmed by the scanning Smartscan Hydra sprayheads. They are looking for an exceptionally high-temperature reading or a differential increase between scans. It is also possible to connect it to a compatible existing early warning alarm as an alternative method of initiating scanning.