Fitting and Guidance

From 1st October 2015 regulations will require landlords to ensure the fire safety of their tenants as well as offer protection against carbon monoxide poisoning. For maximum protection smoke alarms should be fitted in every room – but as a minimum, at least one should be fitted on each level of the house. brief guide to fitting smoke and carbon monoxide alarms (new window, PDF 1410KB)

Which type of smoke detector is best?

There are 4 basic types of smoke detectors: photoelectric (also known as optical), ionization, heat and dual sensor (also known as combined).

  • Photoelectric smoke alarms are designed to detect smoke from a smouldering fire.
  • Ionization smoke alarms are more responsive to flaming, raging fires.
  • Heat alarms detect temperature increases but are not influenced by any smoke.
  • Dual-sensor or combined alarms do a combination of two or more of the types mentioned above in one device. Combined can even mean including carbon monoxide detection.

The question prevails: Which one is the best?

You'd think the general consensus would be to go for dual-sensor alarms as is recommended by the NPFA in the USA and the FPA in the UK, but some argue that they can be prone to false alarms.

In our opinion, it is better to have a photoelectric alarm as your main line of defence as this will start beeping once any smoke is emitted from a slow-burning material e.g. if a cigarette stub is smouldering away in a waste bin.

That is not to say that you shouldn't have an ionisation alarm as these are useful in certain situations where a fire is likely to develop really quickly e.g. embers from a fire lighting up a curtain.

In a kitchen however, it is probably better to go for both photoelectric and heat detector alarms or a dual-detector. An an ionisation alarm can be a bit over-sensitive.

To give a more rounded to the question of 'which is the best smoke detector', we state the best type depending on the room:

  • Bedroom: ionisation detector
  • Bathroom: ionisation or photoelectric detector
  • Communal spaces: ionisation detector
  • Hallways: ionisation or photoelectric detector
  • Kitchen: combined photoelectric and heat detector

Battery Powered or Mains Powered?

In general, this depends on the size of the property. The larger the property, the better it is to have a mains powered smoke alarm system. Mains powered systems usually have a backup battery as well in case there is a power outage. An interlinked smoke alarm system will almost always be mains powered. This system is designed whereby if an alarm goes off in one room, it is interlinked to the alarms in the other rooms, meaning they will start beeping too. You can drill down further by having hardwired-interlinked or radio-interlinked. 

  • Hardwired-interlinked: actual wires connecting each alarm to the next
  • Radio-interlinked: each alarm linked wirelessly through a radio frequency

 A well detailed description of how these systems are connected can be found in this FireAngel guide. In certain situations, you need to have an interlinked fire alarm system by law as is detailed by the FireAngel guide above e.g. if the property is a house in multiple occupation (HMO), then you need to ensure that you've installed mains powered interlinked smoke alarms. These interlinked alarms will usually have to be fitted by a suitably qualified electrician.

How to fit a smoke alarm

Simply screw the alarms into the ceiling and as close to the centre of the room, hallway or landing as possible – at least 30 centimeters (12 inches) away from any wall or light fitting. Always check the manufacturers’ instructions beforehand.

Test the alarms once you have fitted them and remind your tenants to test them regularly. Special smoke alarm kits are available for those who are deaf and hard of hearing people – your local fire and rescue service will have further advice and information.

Finally, make sure your tenants have an escape plan so they get out safely if the alarms alert them to the fact that there is a fire.

How to fit a Carbon Monoxide (CO) alarm

Carbon Monoxide (CO) alarms protect residents by giving an early warning when the poisonous gas is detected in the home. Installing a CO alarm is a simple DIY task, with most detectors only requiring a couple of screws, while some are free-standing and require no installation

Ideally the alarms should be installed next to potential sources of CO in the premises and in sleeping areas. The alarms should be at a horizontal distance of between 1 to 3 metres from the potential source and at least 1.5 metres from the ceiling if fitted on a wall. Avoid putting them too close to windows or air vents.

People suffering from carbon monoxide poisoning should get fresh air immediately, open doors and windows, turn off gas appliances or extinguish other sources, leave the house and see a doctor.

Final Verdict

With all the information above, we cannot categorically state which detector is the best option for your situation. However, if we had the budget to purchase only one or two alarms, we would opt for a dual-alarm, specifically a combined smoke and carbon monoxide alarm with view to placing one in the hallway and the other in the landing upstairs.

To read more articles like this one, please visit our section on alarms.