Many homeowners don't realise that smoke alarms and heat alarms serve different purposes and should be installed in different locations. Here's what you need to know.
Smoke alarms and heat alarms are both essential components of a home fire detection system, but they work differently and are suited to different locations. Understanding the difference could save your life.
How Smoke Alarms Work
Smoke alarms detect the presence of smoke particles in the air. There are two main types:
Ionisation Alarms These contain a small radioactive source that ionises the air inside the detector. When smoke enters, it disrupts the ionisation and triggers the alarm. Ionisation alarms are very sensitive to fast-flaming fires (e.g., burning paper or wood).
Optical (Photoelectric) Alarms These use a light beam inside the detector. When smoke particles scatter the light, the alarm triggers. Optical alarms are better at detecting slow, smouldering fires (e.g., burning foam or overheating wiring) and are less prone to false alarms from cooking.
How Heat Alarms Work
Heat alarms don't detect smoke — they detect a rapid rise in temperature or a temperature above a fixed threshold (typically 58°C). They are ideal for kitchens, where cooking fumes would trigger a smoke alarm repeatedly.
Where Should Each Type Be Installed?
- ✓Hallways and landings — Optical smoke alarm (interconnected).
- ✓Living rooms — Optical smoke alarm.
- ✓Bedrooms — Optical smoke alarm (especially important for sleeping occupants).
- ✓Kitchen — Heat alarm (not a smoke alarm — too many false alarms from cooking).
- ✓Garage — Heat alarm (fumes from vehicles would trigger smoke alarms).
- ✓Loft — Optical smoke alarm if used as habitable space.
Interconnection
All alarms should be interconnected — either by wire or wirelessly — so that when one activates, all alarms in the property sound. This is particularly important in larger homes where an alarm in the kitchen might not be heard in an upstairs bedroom.
Mains-Powered vs Battery
Mains-powered alarms with battery backup are strongly recommended. Battery-only alarms are acceptable but require regular battery replacement.
Scottish Regulations
Since February 2022, Scotland has required all homes to have interlinked alarms. England is expected to follow with similar requirements.
Future Smart Electrical installs and maintains smoke and heat alarm systems across Essex. Contact us for a free assessment.