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Smoke and Gas Detectors/Alarms Buying Guide

Introduction

Smoke, heat and CO detectors are a vital component in ensuring your home and business environment is safe and compliant. It’s estimated that twice as many people die from fire-related smoke and gas inhalation than burns, meaning it’s essential to equip your business or home with fire-safety technology.  

Fire and CO detectors act as the first defence against smoke, gas and fire. This is achieved by providing a crucial early warning of the presence of these elements, giving people in the building the opportunity they need to escape in time. Smoke and potentially deadly gases typically spread much faster than flame heat, making smoke and gas detection devices absolutely necessary. 

UK government guidelines don’t specify the exact type of fire alarm required for a particular premises. However, current UK fire detector regulations state all business premises must have an appropriate fire detection process in place. 

There is also the requirement for UK landlords to place smoke alarms on every floor of a residential property. So, if a fire were to occur, there must be a system to not only detect the presence of fire – but also give plenty of warning to people both in and around the building. 

Installing reliable smoke and heat detectors is therefore a simple yet effective method of maximising safety, giving greater peace of mind to home owners, business owners and employees, and ensuring legal compliance. The same goes for gas detectors, specifically CO alarms. UK regulations require that, in the private and social sector, landlords ensure that CO detectors are present in any room containing a fixed combustion appliance (other than a gas cooker). This includes, for example, a boiler. 

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Smoke & Heat Detectors

Choosing the right smoke alarm for a specific room in your home, rented property, or workplace can be challenging. Manufacturers offer various types of smoke detector sensors tailored for us in different rooms and to manage various fire risks. Using the appropriate detector type ensures quick response to fires and minimizes false alarms. Below is a guide to the recommended smoke detectors for different rooms and the reasons behind these choices.

Main Types of Smoke Detectors

There are four primary types of smoke detectors: optical, ionisation, heat, and multi-sensor (combined).

The suitable type depends on the room where it is installed and the combustible materials present.

1. Ionisation Smoke Alarms

 

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Contain a small radioactive source, and are becoming less common. Optical smoke alarms are recommended as replacements for comparable effectiveness and safety.

2. Optical Smoke Alarms

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Optical Smoke Alarms are ideal for a range of common areas such as bedrooms, living rooms, dining rooms, hallways, landings and office space. These alarms are better at detecting slow, smouldering fires such as those involving fabric or wiring, and are less prone to false alarms compared to ionisation alarms. They are sensitive to large particles in the air, by using infrared light detection. However, generally they should not be used in dusty environments or areas open to the elements.

3. Heat Alarms

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Heat Alarms or heat detectors, are fire detection devices that trigger an alarm when the temperature in a protected area reaches a pre-set level or when the temperature rises rapidly. They are less sensitive to false alarms from cooking fumes, steam, or dust, making them suitable for environments where such conditions are common. Common applications include kitchens, garages, attics, and industrial environments with high ambient temperatures or areas where smoke detectors might be prone to false alarms due to dust, steam, or exhaust. Heat alarms are also used in spaces where the detection of smoke is less practical or in combination with smoke alarms for added safety.

4. Multi-Sensor, or Combined Smoke Alarms

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Multi-Sensor, or Combined Smoke Alarms combine different types of sensors for improved detection and reduced false alarms. They include smoke and heat detectors, as well as combinations like smoke and Carbon Monoxide (CO) detectors or heat and CO detectors. They are not suitable for kitchens, but can be used in locations such as landings, offices, bedrooms, living rooms or hallways.

Power Sources: Battery vs. Mains-Powered Smoke Alarms

1. Battery-Powered Alarms

 

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These can be either alkaline or long-life lithium batteries, with different lifespans:

  • Standard lithium: 10 years
  • Radio-interlinked lithium: 2-5 years
  • Alkaline: 1 year

It is possible to buy interlinking battery powered alarms. 

2. Mains-Powered Alarms

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Mains-powered detectors offer better protection but usually require professional installation. They come with various backup battery options for when there is a power failure:

  • Alkaline: lasts 12-18 months
  • Non-rechargeable lithium: 5-10 years
  • Sealed rechargeable lithium: lasts the alarm's lifetime (10 years)

Mains smoke and heat alarms with an alkaline battery backup offer a safe and economical option. Depending on the frequency of testing how often they sound, the backup battery typically lasts around 12-18 months before needing replacement. However, manufacturers advise replacing the batteries every 12 months to ensure the detector remains fully operational.

Some mains-powered smoke alarms can be upgraded to use non-rechargeable lithium backup batteries. These batteries, which are not sealed within the alarm, generally last 5 to 10 years before needing replacement, although their lifespan can be reduced to 2-5 years in radio-interlinked alarms. It is important to check the product manual to confirm compatibility with non-rechargeable lithium batteries.

Additionally, mains-powered alarms are available with a sealed-in rechargeable lithium backup battery, designed to last the lifetime of the alarm (10 years) without the need for replacement. This option is particularly cost-effective and ideal for rental properties where battery removal or depletion could be problematic.

2.1 Connecting Mains-Powered Smoke Alarms

 

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Mains-powered smoke detectors and heat alarms can often be connected to the nearest lighting circuit or a dedicated circuit from the distribution board. Connection via lighting circuits is usually more cost-effective and less likely to be disabled to stop the "nuisance" of beeping alarms when the backup battery runs low. Please note that you must ensure that the light switch does not affect power supply to the alarms.

Smoke Detector Grades and Categories

Fire detector grades are specified by BS 5839-6:2019. Previously rated A – F,  the most recent update has removed Grade B and Grade E, whilst Grade D and Grade F have each been split in two. Grade C has also been revised. Broadly, A is considered the highest grade, while F is the lowest. 

At VSafety we specialise in smoke detectors that fall into grades D to F. Residential buildings can usually meet UK fire alarm regulations with these grades of system. 

Grade F2, Category LD2

Domestic, owner-occupied housing

Grade D2, Category LD2

Extensions of domestic housing

Grade D1, Category LD2

Rented properties

Grade A, Category LD2/L2

Communal areas in flats or HMOs

Grade D1, Category LD1 or LD2

Individual units in flats or HMOs

Mains-powered alarms must have a backup battery and interlink to meet BS 5839 Pt 6 Grade D1 and D2 standards – this means all will sound when one detects a fire. Battery-powered alarms, suitable for Grades F1 and F2, are easier to install and may or may not have wireless interlink capabilities.

Mains Powered Smoke Alarms with Backup Battery – Grade D

 

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Battery Operated Smoke Alarms – Grade F

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Commercial and business premises will usually require a more complex fire alarm system interconnected through a control panel, purchased and installed through specialist contractors. 

If you’re yet to equip your business with such fire-safety technology, these grading systems may appear confusing. Your fire risk assessment will uncover exactly which graded system your building needs, ensuring you provide the best safety possible.

Smoke Detectors Installation and Maintenance

Install smoke alarms immediately upon purchase, following manufacturer instructions. Position them in the centre of the ceiling, at least 30cm away from walls and light fittings. Replace alarms every 10 years to maintain sensor sensitivity. Recycle old alarms appropriately.

It’s important to not only test the function of your smoke and CO detectors when first installed, but also on a regular basis. Testing these devices not only ensures the detection mechanisms are working, but also checks their power supply is functioning optimally too. Each type of smoke and CO detector will have instructions on how to test, so make sure to refer to your device’s specific manual.

A single false alarm is not unusual. From disrupted airflow to a build-up of debris, there are many reasons for these devices to emit an outlier false alarm. 

However, if your devices are regularly going off, this will require some investigation. The worst thing you can do is to ignore frequent false alarms. Whether due to a poor location or batteries running low, take the time to test and make changes accordingly. If no amount of relocation, battery changes or cleaning is enough to stop the false alarms, you will need to replace your devices. 

If dust and other debris are allowed to build up on or in your detectors, this can severely impair their function. Regarding the outside of your devices, simply wipe clean with a damp cloth as and when you start to see dust build up. 

The inside of your devices must also be cleaned, too. A great way to ensure this gets done is to put time aside for cleaning each time you change the batteries. This way, you’re guaranteeing a deep clean every year, which is the recommended amount. To effectively clean the inside of your smoke or CO detector, a small vacuum hose is the ideal tool. 

By selecting the correct smoke detector for each room and ensuring proper installation and maintenance, you can enhance fire safety in your home or workplace.

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Carbon Monoxide (CO) Detectors

CO detectors are designed to measure CO levels over time and are calibrated to sound an alarm before potentially dangerous levels of CO accumulate, giving people adequate time to safely ventilate the area or evacuate. Some detectors are also equipped with a digital screen to provide a readout of the CO concentration in parts per million (ppm). Such CO detectors can be either battery or mains-powered, and should be placed in any part of a building containing a combustion appliance such as a boiler or a gas fire. 

As Carbon Monoxide is heavier than air, many people assume that CO detectors shouldn’t be installed too high. However, this is not the case. The best place to install your CO detector is on the ceiling too, and should be placed within close proximity to all potential sources of Carbon Monoxide. Anywhere between 1-3 metres is considered ideal. If the fuel burning appliance in question (such as a boiler) is fitted within a small confined space, your CO detector should be installed on the ceiling just outside the room. If the alarm is situated too close, it could be rendered less effective. 

Similar to smoke alarms, CO detectors should be placed at least 30cm away from any possible obstructions. 

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Smoke & CO Detector Regulations

The Smoke and Carbon Monoxide Alarm (England) Regulations 2015 are the UK’s current primary smoke and CO detector regulations. However, these mainly focus on landlord obligations for residential rental properties. As a result, business regulations for commercial buildings aren’t quite the same – but similar principles regarding safety always apply. 

Fire risk assessment

A fire risk assessment is a legal must-have for all commercial and business premises. Whoever is directly responsible for the maintenance of the building is obliged to arrange these assessments, with heavy fines as penalties for failing to do so. 

A fire risk assessment will uncover precisely what type of system will be best suited for the building in question. From identifying specific device grades to establishing emergency evacuation plans, these assessments are crucial for ensuring fire safety remains a priority. 

Professional maintenance

While it’s important to carry out basic maintenance tasks yourself (changing batteries, cleaning devices etc.), having your fire-safety system professionally checked by experts is crucial to ensure optimum function. 

The UK Fire Alarm Regulations specify that your fire alarm system must be ‘adequately maintained’, and this should involve a professional inspection. This is typically recommended to happen every 6 months to a year. 

Testing

Testing your smoke & CO detectors goes beyond manually pressing the test button. It’s required by law for building duty holders to test smoke alarms on a weekly basis. This is not only crucial to ensure your devices are working properly, but it will also familiarise everyone in the building with what the fire alarms sound like. 

So, in the event of a real fire, building users will instantly recognise the sound. This will cause less confusion and more urgency, increasing the chance of a smooth and efficient evacuation process. 

Weekly fire alarm testing must also be logged. All points tested must be recorded, with any issues reported and investigated. 

Why Buy From VSafety?

Meeting your fire safety obligations are an essential consideration for any organisation with premises, we want to make it as easy as possible for you to deal with us. Join the thousands of customers who have benefitted from our exceptional customer service, low prices, comprehensive range, and quality product guidance.

Speak to us! You can call our friendly team FREE on 0800 030 8010, chat to us online or email us at sales@vsafety.co.uk

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