VESDA VLF Aspirating Smoke Detector


Key Features

  • Laser Based Absolute Smoke Detection
  • Very Early Warning of a Potential Fire Incident
  • Wide Sensitivity Range
  • Dual Stage Dust Filtration
  • Programmable Alarm Thresholds


VESDA VLF by Xtralis provides superior very early warning, air-sampling smoke detection for small, business-critical spaces such as switch rooms, server rooms and cabinets.

VLF aspirating smoke detectors continually draw air into the sampling chamber via discrete sampling holes in an aspirating pipe network. The air is filtered before entering the chamber, where light scattering technology detects even a very small amount of smoke. The detector communicates its status information on its intuitive ‘smoke dial’ display and via relays or optional interface cards.

VESDA VLF is available in two versions:


VESDA VLF-250 aspirating smoke detectors are designed to protect small, business-critical environments of less than 250 m2 (2,690 sq. ft.).


VESDA VLF-500 aspirating smoke detectors are designed to protect small, business-critical environments of less than 500 m2 (5,380 sq ft).

Smoke Dial Display

VESDA’s unique Smoke Dial™ display gives the user an instant understanding of a smoke event. Smoke Dial™ uses a circular LED display and well-placed icons to provide a visual indication of smoke growth and alarm conditions, even from a distance.

In fault conditions, VESDA’s Smoke Dial™ display doubles up to provide VESDA’s innovative ‘Fault Finder’ feature – a smart diagnostic feature that provides instant and meaningful information of the detector’s status without the need for evaluation tools or additional programming. VESDA’s Fault Finding feature allows fire and maintenance staff to be better informed before arriving on site, saving time and reducing maintenance costs.

Ultrasonic Flow Sensing

VESDA VLF is the first air sampling smoke detector to use Xtralis’ patent-pending Ultrasonic Flow Sensing to provide a direct reading of the sampling pipe flow rate. This system immediately identifies and communicates any variances in the airflow and is unaffected by pressure and air temperature changes and is impervious to contamination.

Ease of Installation

VESDA VLF detectors provide out of the box installation and do not require a special interface or software programming tools


VESDA’s AutoLearn feature further assists the installation process by assessing environmental conditions and automatically setting acceptable smoke alarm and flow fault thresholds.

VESDA Software Compatibility

VESDA VLF detectors are fully supported by the VESDA System Configurator Software (VSC) which offers a high level of programming flexibility through its online and offline platform, and ASPIRE, that provides design wizards, isometric views, an automated design verification process and improved AutoBalance capabilities to simplify the design process.

Typical Applications

VESDA VLF aspirating smoke detectors provides very early warning air sampling detection for small areas such as:

  • Local Telecommunication Exchanges
  • Correctional Facilities
  • Smaller Server Rooms
  • Utility Control Hubs
  • Control Rooms
  • Railway Signal Hubs
  • Switch Rooms
  • Cabinets
  • Storage Facilities
  • Substations
  • Air-handling Units


The VESDA VLF is fully approved by VdS for safe use and installation in any European Union country and bears the CE mark to show that it complies with all the applicable Directives including the CPR, EMC and the Low Voltage Directive (LVD).

EN54-20:2006 + AC:2008 – Fire detection and fire alarm systems – Control and indicating equipment.

Tech Specs

Input PowerVoltage: 24Vdc Nominal (18-30 Vdc)

Current @ 24Vdc
VLF-250: 220 mA nominal, 295 mA in alarm
VLF-500: 410 mA nominal, 490 mA in alarm
Dimensions (W x H x D)256mm x 183mm x 92mm
WeightApproximately 2kg (4.4 lbs)
IP RatingIP30
MountingUpright, inverted or horizontal
Operating ConditionsAmbient: 0°C to 39°C (32°F to 103°F) Product UL listed for use from 0°C to 38°C (32°F to 100°F)
Tested to (EN54-20): -10°C to 55°C (14°F to 131°F)
Sampled Air: -20°C to 60°C (-4°F to 140°F) Sampled Air temperature shall reach Ambient Detector temperature upon entry into Detector. Refer to Xtralis Design Guides & Application Notes for sampled air pre-conditioning.
Humidity: 5% to 95% RH, non-condensing
Sampling HolesVLF-250:
Class A (12 holes / 0.12% obs/m)
Class B (12 holes / 0.35% obs/m)
Class C (12 holes / 0.80% obs/m)

Class A (30 holes / 0.05% obs/m)
Class B (30 holes / 0.15% obs/m)
Class C (30 holes / 0.32% obs/m)
Sampling NetworkMaximum pipe lengths
VLF-250: 1 x 25m (80ft) (Max. 12 holes), 2 x 15m (50ft) per branch (Max. 6 holes per branch)
VLF-500: 1 x 50m (150ft) (Max. 24 holes) 2 x 30m (90ft) per branch (Max. 12 holes per branch)

Sampling Hole Options: Pre-Engineered Option or Maximum Pipe length in accordance with Pipe Modelling Design Tool (ASPIRE™)
Air Inlet PipeAccepts both metric and American standard pipe sizes
Metric: 25mm (1.05 in.) American Pipe: IPS 21mm (¾ in.)
Area CoverageVLF-250: Up to 250 m2 (2,690 sq. ft.) depending on local codes and standards
VLF-500: Up to 500 m2 (5,380 sq. ft.) depending on local codes and standards
Relay Outputs3 changeover relays (Fire 1, Action, Fault), Contacts rated 2A @ 30Vdc (max). NO/NC Contacts
Cable Access3 x 25mm (11/16in.) cable entries (1 rear entry, 2 top entry)
Cable TerminationScrew Terminals 0.2-2.5 mm2 (30-12 AWG)
InterfacesShown in Terminal Block Connections diagram, to right, plus an RS232 Programming Port.
General Purpose Input (GPI) interface offers: Reset, Disable, Standby, Alarm set 1, Alarm set 2 and External Input functions.
Alarm Threshold Setting RangeAlert, Action 0.025 – 2.00% obs/m (0.008 – 0.625% obs/ft)
Fire 1, Fire 2 0.025 – 20.00% obs/m (0.008 – 6.25% obs/ft)
Individual Alarm Delays 0 – 60 seconds
Two Alarm Threshold Settings Either time or GPI based
Display4 Alarm State Indicators
Smoke Level Indicator
Reset, Disable and Test Controls
Fault and Disabled Indicators
Instant Fault Finder
Smoke and Flow AutoLearn Controls
Event LogUp to 18000 events, time and date stamped in separate, non-volatile, logs for: Smoke Level, Flow Level, Detector Status and Faults
AutoLearn Smoke & FlowAutomatically set acceptable alarm thresholds for both smoke and flow levels
Minimum 15 minutes, maximum 15 days (default 14 days)
During AutoLearn, thresholds are NOT changed from pre-set values



Eurofyre is an authorised distributor of Honeywell and has been a major technical wholesaler of Xtralis products since 2007. We offer expert advice and supply all aspects of VESDA, FAAST and ICAM aspirating smoke detection systems including pipework calculations, demonstration/training and excellent after-sale support.

Contact us to receive competitive trade discounts or apply online for a credit account.