Heat Detectors Overview
Heat Detectors generally fall in to two categories - Fixed Temperature Heat Detectors and more commonly, Rate of Rise Heat Detectors.
Fixed Temperature Heat Detectors
A Fixed Temperature Heat Detector utilizes a temperature sensing element which will generate an alarm condition if the temperature within the protected area reaches a pre-determined level e.g. 60ºC or 90ºC.
These detectors are used where high ambient temperatures exist or where sudden changes in temperature can occur e.g. kitchens, boiler rooms & foundries etc. A fixed temperature trigger point should be selected which is most suitable for the situation in question.
Rate of Rise Heat Detectors
A Rate of Rise Heat Detector will include a fixed temperature element as above but will in addition include a temperature sensing element which can detect a sudden change in temperature.
This type of detector is more sensitive than a simple fixed temperature heat detector and as such is the choice for applications in which reliable performance and early warning are critical but where the environment makes smoke detection unsuitable.
Note:
Heat detectors are, in general, less sensitive than other types of detector and should therefore not be used where a small fire will lead to unacceptable losses.
Examples of suitable locations for Heat Detectors
Before selecting the type of heat detector it is necessary to confirm the environment into which the installation is to be placed e.g. are there local heat generating facilities such as ovens, burners, process machinery? What is the maximum temperature achieved in the protected area?
| Location | Rate of Rise | Fixed Temp | Fixed High Temp | Reason |
|---|
| Boiler Room | | # | # | Rapid change in room temperature |
| Drying Room | # | | | |
| Kitchen | | | # | Avoid locations over ovens |
| Loading Bays | # | | | |
| Smoky Atmosphere | # | | | |