VESDA is a family of aspirating smoke detectors (ASD) from Xtralis. Instead of waiting for smoke to drift to a ceiling-mounted point detector, an aspirating system continuously draws air through a network of small-bore pipes to a central detector unit, where it is analysed for the earliest traces of smoke. That makes it a strong option wherever an early warning, rather than a late alarm, can prevent injury, damage or costly downtime.
What is aspirating smoke detection?
An aspirating system has three main parts: a pipe network with sampling points drilled along its length, a detector unit containing a fan (the aspirator) and a high-sensitivity laser-based smoke sensor, and a filter that removes dust before the air reaches the sensor. Because the detector samples air actively and can be configured with several alarm thresholds, it can report a developing problem at a very low smoke level, then escalate through pre-alarm, alert and fire stages as the level rises. Sensitivity does not rely on smoke reaching a ceiling, so the system also performs well in high bays, ducts, under raised floors and in air-conditioned spaces where smoke is diluted or carried away.
Where VESDA is used
- Data centres and telecoms rooms: very early warning lets staff investigate before equipment is damaged or a gas suppression system discharges.
- Heritage and cultural buildings: sampling pipes are small and can be discreetly routed, which suits historic interiors where ceiling-mounted devices are unwelcome.
- Clean rooms and healthcare: detection can be pipe-mounted with the detector unit sited outside the controlled space, so servicing does not disturb the environment.
- Warehouses and cold storage: high ceilings, racking and low temperatures make point detection difficult; pipework can follow the racking or use specially rated components for freezers.
- Other applications: records storage, power generation, transport, marine and switch rooms.
VESDA ranges
The current VESDA-E range includes the VEP, VES, VEA and VEU detectors, which differ in the number of pipes and the area they can cover, so the right model depends on the size and layout of the space. We stock the Xtralis VESDA-E VEP 4-pipe detector with LED display (VEP-A00-P), together with a wide selection of accessories: pipe, fittings, clips, sampling-point labels, filters, power supplies and the VESDA smoke pen, as well as OSID open-area smoke imaging components and gas sensor options for the VEA. Browse the full VESDA Xtralis collection. For open spaces where a pipe network is impractical, also see our beam and aspirating detection range.
Sensitivity classes under EN 54-20
Aspirating smoke detectors are tested to EN 54-20, which defines three classes:
- Class A, very high sensitivity: intended for the earliest possible warning of a very small fire, typically in critical areas such as data centres and clean rooms.
- Class B, enhanced sensitivity: suited to areas where earlier warning than a standard system is wanted, for example high-value storage or spaces with high airflow.
- Class C, normal sensitivity: comparable to conventional point detection, covering large areas from a single detector.
The class achieved depends on the detector and on the design of the pipe network (pipe length, number of sampling holes and their size), so it should be confirmed by the system designer against the manufacturer's design tools. Always follow the relevant design standard and the guidance of the specifier or fire risk assessor for the premises.
Maintenance basics
- Filters: the dust filter protects the sensor and should be inspected and replaced at the intervals the manufacturer recommends, more often in dusty or dirty environments. Replacement items such as the VESDA VSP-962 filter cartridge are available.
- Pipe network: check that pipes are intact, joints are secure, end caps are fitted and sampling holes are clear and unblocked. Damaged or altered pipework changes airflow and can affect sensitivity.
- Airflow and fault status: review airflow readings and any fault indications at the detector and investigate changes promptly.
- Functional testing: periodically test response by introducing smoke at the furthest sampling point, and keep a record of results.
- Servicing: routine inspection and testing should be carried out by competent persons at the intervals set out in the maintenance schedule, in line with the manufacturer's instructions.
Choosing a system
Start with the risk. Consider what is being protected, how costly an interruption would be, the size and height of the space, airflow and air-conditioning patterns, temperature range and how dusty the environment is. These factors determine the detector model, the sensitivity class, the pipe layout and the filtering needed. Early smoke detection buys time to investigate, isolate equipment or begin a controlled response, and it can reduce the likelihood of false alarms because alarm thresholds and delays can be tuned to the environment. Where the detector is connected to a fire alarm panel or a suppression system, check compatibility and commissioning requirements with the installer before ordering.
Not sure which detector or accessories you need? Browse the VESDA Xtralis collection or contact our team with your room sizes and application and we will point you to suitable parts.