FIRE & SMOKE ALARMS
At Whitehouse Electrical & Sons we want you to be certain that you and your family are safe should there be a threat of fire in your home. We can advise on and install smoke and fire detectors correctly in your home.
What Are Various Grade Systems?
The BS 5839: Pt.6 standard places different alarm types into Grades A to F. For Domestic fire alarm system the minimum grade is D – mains smoke & heat alarms with a battery back-up supply. All new-builds require smoke and heat alarms complying to Grade D.
What Type Of Sensors Are Available & What Are The Differences?
Smoke alarms either contain an Ionisation or an Optical sensor. Each type of alarm senses fire in a different way and are better suited for different situations.
Ionisation Smoke Alarms contain a small sealed ionising source which causes a small electrical current to flow through the air in the smoke chamber. Smoke particles entering the chamber reduce the current, thus sensed by the electronics and when a pre-set threshold level is reached the alarm will sound. These alarms are best suited for detecting fast flaming fires and are better suited in rooms where there is a high risk of fire (except the kitchen). Ionisation alarms are more prone to false alarms due to their sensitivity and therefore ideal locations for these alarms are living room and bedrooms.
Optical Smoke Alarms send a pulsed beam of infra red light through the smoke chamber periodically. If visible smoke is present, it scatters the light on to the photo diode light receiver and this is detected by the electronics causing the alarm to sound. These alarms are better on escape routes and designed to detect smoldering fires. This type of detector is less prone to false alarms.
Heat alarms are incorporated in to a fire alarm system. As the name implies heat alarms only detect heat and not smoke.