Betta Fire Protection has spent over 40 years installing, maintaining smoke alarms and carrying out smoke alarm inspections and testing, so we thought we’d share some info on the different types of smoke alarms and which smoke alarm solutions are best for your site. 

Depending on the building, the requirements for smoke alarms will vary. Therefore, it is always recommended you chat to a fire safety specialist so you can ensure your property’s essential fire safety measures are compliant and that your smoke alarms are installed and maintained in line with the necessary smoke alarm standards. 

There are three main smoke alarm types: photoelectric, ionisation and thermal/heat. These are available in a range of smoke alarms power supply options: hard-wired 240v, 9v alkaline battery, 9v lithium 10 year battery, or a combination of both, interconnected with each other (i.e. if one goes off, they all go off). This can be via a cable or using wireless radio communication.

So what’s the difference? And which smoke alarm solution is right for your site? Read on to find out. 

Types of Smoke Alarms

Photoelectric Smoke Alarms 

Photoelectric smoke alarms are designed to detect particles of combustion. The alarm is activated when smoke particles enter the sensing chamber, in turn, the sensor is triggered. 

This type of smoke alarm performs faster in smouldering fires that produce a lot of smoke, which is the most common type in the home environment. Therefore photoelectric smoke alarms reduce the risk of smoke inhalation for building occupants as they are alerted to the fire quicker and can escape in time. 

Ionisation Smoke Alarms

Ionisation smoke alarms work by essentially “smelling” smoke. The alarm is activated when smoke enters the chamber containing a small amount of radioactive material between two electrically-charged plates and disrupts the air current. Ionised smoke alarms are slowly phasing out, with a preference for photoelectric smoke alarms.

The benefit of ionised smoke alarms is that they tend to activate quicker for flaming fires. Ionised smoke alarms also tend to have more false alarms, i.e. they can be too sensitive and cause more nuisance alarms. 

Thermal/Heat Alarms 

A thermal or heat detector technically isn’t a smoke alarm as it doesn’t detect smoke. Instead, they are set off by temps above 63Oc. For this reason, they are great for areas such as kitchens and bathrooms where traditional smoke alarms are triggered too often by cooking or steam, however, the downside is that they can leave building occupants susceptible to smoke inhalation if a fire does break out. 

Smoke Alarm Connections

Battery operated Smoke Alarms

Battery smoke alarms are battery operated. For battery-operated smoke alarms, we always recommend 10 year lithium batteries as opposed to lead or alkaline batteries which need to be replaced yearly.  Some battery smoke alarms are able to be interconnected with radio communication. 

Hard-Wired Smoke Alarms 

A hard-wired smoke alarm consists of a 240-volt power supply with a battery backup. This means that if power is interrupted, the alarms won’t be impacted.  

Interconnected Smoke Alarms 

Interconnected smoke alarm solutions mean that if one smoke alarm is activated, all of them are. As smoke alarm installation experts, we’ll make sure you have the right type of smoke alarm, and the right connection while ensuring it’s positioned in the right place to avoid false alarms and meet all necessary compliance standards. 

Smoke alarms are most effective in residential settings as they are relatively cheap and easy to install while being great at detecting fire.

Smoke alarms generally only provide a local audible alarm, which makes them great at warning people who are in imminent danger from the fire, such as people asleep in a bedroom. 

They are less effective in non-occupied buildings, such as an office outside of business hours as they only cover a small area (about 10m x 10m). They can be interconnected to cover multiple levels or rooms; however, the limit of the number of interconnected devices is normally between 12-20.

Looking to connect your fire detectors with other fire safety measures? Ask us about our more advanced fire alarm and detection systems for Strata, commercial and industrial premises.

Call our team today on (02) 8669 9100 to discuss your fire safety needs and see which smoke alarm solutions suit your needs best.