Fire is a very common hazard which can be life-threatening and is a matter of serious concern. A fire breakout can be dangerous to property, causing some very serious losses. Heat detectors are a vital component of a fire alarm system and play an important role in the detection of fires. This article speaks about a few things you need to know about heat detectors.
Heat Detectors for Property Protection
An important factor that must be taken into account is that heat detectors are mainly used to safeguard property. Many times, smoke detectors are unsuitable in areas that have too many particles that are airborne due to the presence of plenty of dust, moisture, humidity, steam, temperature, etc. Also, installing smoke detectors in such places can be extremely prohibitive in terms of cost of maintenance. In such cases, heat detectors are very beneficial.
Electronic vs Mechanical Heat Detectors
Electronic Heat Detectors
These sense heat by making use of a thermistor, which is essentially a device that alters resistance when there is a change in temperature. Heat detectors have added features such as blinking LED indicators that indicate that the heat detector is in standby mode and is working properly.
Mechanical Heat Detectors
There are two types of mechanical heat detectors: pneumatic and bimetallic.
Bimetallic Heat Detectors: These detectors contain a metallic strip with two different metals. As the heat reaches the strip, the metal warps and the contact is closed and the alarm is activated. Bimetallic heat detectors are quite simple in construction and are also quite inexpensive.
Pneumatic Heat Detectors: In these kinds of heat detectors, there is a flexible diaphragm that is sealed within an air chamber. In case of a fire, the air within the chamber becomes warm. The chamber begins to expand, thereby distorting the diaphragm. This causes pressure to be applied on the contacts and an electrical connection is completed, which sounds the alarm. Pneumatic heat detectors are commonly used in severe environments as they can be protected against the corrosive and harsh elements.
In general, electronic heat detectors are expensive when compared to mechanical detectors.
Fixed Temperature Vs Rate-Of-Rise Heat Detectors
Fixed Temperature Detectors
These are the most commonly used heat detectors. Fixed temperature detectors work by keeping track of the temperature in the room. When the ambient temperature rises more than a particular set point, the detector is activated and the alarm is sounded. However, once activated these detectors are destroyed and can’t be reused.
Rate-Of-Rise (ROR) Detectors
ROR heat detectors are activated when the ambient temperature rises at a predetermined rate that is set during the manufacturing of the device. However, in case of a fire that builds up and spreads slowly, the ROR heat detector may not be effective. ROR detectors can be restored and re-set once they are activated.
Spot Type Vs Linear Type Heat Detectors
Spot Type Heat Detectors
These type of heat detectors are basically fixed at a single place and the detection mechanism is located in one physical spot.
Linear Heat Detection
In the case of linear heat detection, the detection element is spread across a large coverage area. This detection system makes use of a multi-core cable or wire which has two insulated conductors that have a specific melting point. This melting point is in correspondence with the set point. When the temperature rises to a point where the insulation of the two conductors melt, the conductors come into contact with one another and shorting occurs which causes the alarm to be sounded. Linear heat detectors are quite popular in industrial locations as they can cover large areas.
Heat detectors cannot really be termed as “life safety equipment”. However, they play a key role when it comes to protecting your buildings and property from damage due to fire.
Cygnus heat detection systems are best in the industry and have consistently been providing top quality products that can safeguard your premises and assets in the best possible way.