Burning is not the only hazard that arises in case of a fire. In fact, we often underestimate smoke inhalation, but it causes twice as many fatalities as burns. Deadly gases produced by a fire also spread faster and further than the heat.
Installing smoke detectors in your home can help reduce the risk and prevent such dangers from accidental fires. This guide will help you understand the different types of smoke alarms, how they work, and their pros and cons to inform your decision.
What a Smoke Detector Does
A smoke alarm detects smoke and alerts you and your loved ones to an imminent fire.
Smoke alarms source power from 9V batteries or household electricity, with some models combining both power sources.
They consist of two parts: a sensor that detects the presence of smoke and signals an alarm and a control unit that allows you to set sensitivity levels, test the device’s functionality, and silence false alarms, among other functions.
Depending on their design, most modern smoke detectors use photoelectric sensors or ionisation technology to detect particles in the air caused by combustion from fires.
The Two Types of Smoke Detectors
There are two primary types of smoke detectors; photoelectric and ionisation. Photoelectric detectors are well-suited to detecting smouldering fires, while ionisation models are better at picking up fast flaming ones.
How a Photoelectric Smoke Detector Works
A photoelectric smoke detector works by sending out infrared rays that detect the presence of smoke in the air.
When they hit the smoke particles, these infrared rays scatter and trigger an alarm signal. The prompt allows the detector to sense fires quickly before visible flames appear.
Photoelectric smoke detectors are more efficient with smouldering fires. Their sensors recognise larger particles like those generated when you leave a cigarette unattended or when electrical equipment overheats. This type of fire detection system can save lives and property damage since it detects slow-burning fires early.
How an Ionisation Smoke Detector Works
An ionisation smoke detector detects smouldering fires using a small amount of radioactive material, typically Americium.
This radioactive material emits a stream of alpha particles which cause the air inside the chamber to become ionised, creating an electrical current between two electrodes.
When smoke particles enter the chamber and disrupt this electrical current, it triggers an alarm circuit that sounds off an alert.
These detectors are particularly effective in detecting fast-flaming fires due to their sensitivity to smaller smoke particles, such as those from burning wood or paper.
Pros & Cons
Pros of Photoelectric Smoke Detectors
▪ Photoelectric smoke detectors detect smouldering fires quickly and accurately.
▪ Easy to install and require little maintenance
Cons
▪ These units rely on light scattering for detection, so dust accumulation in the unit can interfere with its proper functioning.
Pros of Ionization Smoke Detectors
▪ These detectors work exceptionally well in picking up smaller particles
▪ Ideal for home environments where different materials could catch fire easily
▪ Affordable and easy to install
Cons
▪ Ionisation smoke detectors use low levels of radiation and require regular testing.
▪ They rely heavily on air currents, so poor ventilation can reduce effectiveness.
Having the correct type of smoke detector in your home is vital to ensure the safety of you and your loved ones. When choosing a smoke detector, it’s essential to consider factors such as environment, budget and ease of installation. Talk to an expert and determine what smoke detector works best for you.
