VESDA and FAAST draw air through sampling pipes to a detector. To choose between them, compare the specific models against the required sensitivity, environment, pipe layout and connection to the fire alarm system.
Written by Oliver Marston — Gent fire detection engineer since 1996, BAFE SP203-1 approved designer, formerly Gent technical support
Start with the design requirement and the exact detector model. VESDA and FAAST are product families: the brand name alone does not establish the interface, sensitivity or suitability for a particular site.
An aspirating detector draws samples through holes in a pipe network. The pipe layout, sampling-hole design and transport time are part of the system design. For the operating principle, see our VESDA and aspirating detection guide.
Compare the proposed models using their manufacturer’s design guidance. A detector’s headline sensitivity or maximum pipe length is not enough to confirm that a particular layout will meet the project requirement.
Begin with the specified VESDA model and the area it will protect. Record the required alarm levels, sampling layout, environmental conditions and how alarms and faults will reach the fire alarm system.
Use the current model datasheet and pipe-design guidance to check that schedule. Our VESDA range is a starting point for identifying the equipment; a family name is not a completed design.
FAAST FLEX is available in conventional and addressable versions. The conventional version provides relay outputs; the addressable version adds a panel-loop connection and also has relay outputs. Xtralis sets out the difference in its FAAST FLEX product comparison.
Confirm the full part number and the supported panel before selecting an addressable unit. An addressable connection is a feature of the particular version, not a rule that applies to every FAAST detector. See the FAAST range for equipment enquiries.
For either family, establish which fire, pre-alarm and fault signals the design needs, how they will be connected, and what power supply is required. Check these against the chosen detector’s manual and the receiving panel or interface documentation.
An addressable connection does not remove the need to check the detector’s separate power requirements. Record the required responses in the cause-and-effect schedule, then include the connections and responses in commissioning checks.
Send the protected risk, drawings, environmental conditions, existing panel details and proposed detector models. Include the required sensitivity class, alarm stages and any site constraints that the designer has identified.
We can then help identify the equipment for that specification. Request a quote with the design details and the full model numbers where you have them.
A site can use different detection systems where the overall design provides for them. Check the chosen models, interfaces and power supplies, and document how each alarm and fault is handled by the fire alarm system.
An aspirating system draws air through sampling pipes to a detector. Its performance depends on the detector and the sampling-network design, including transport time. Active sampling alone does not guarantee an earlier response on every installation.
Pipe network limits are set by the detector's aspirator performance and the transport time required to move a sample from the furthest hole to the detector within an acceptable period. Manufacturer pipe-modelling software is used at design stage to balance pipe length, the number and size of sampling holes, and hole sensitivity so that the network remains compliant and responsive. Send your layout with a quote request if you need the network checked.
Check the exact detector’s environmental limits, filtration arrangements and maintenance instructions. Dust and other contaminants remain design and maintenance considerations; do not assume an aspirating system removes them.
Oliver Marston has worked on Gent fire detection systems since 1996 and is the BAFE SP203-1 approved designer at Midland Fire Direct, a Gent Platinum Partner supplying the fire trade across the UK, where he leads the engineering team. He specifies and commissions systems to BS 5839-1 daily.
Send us the risk and the layout and we will advise on VESDA or FAAST. Trade supply, quote-only.
