005: Air sampling detectors, early detection of fire!

Air sampling detector (ASD) also called aspirating or early warning detector used for fast detection of fire at the early stages. It consists of a central unit (sensor + suction motor) which sucks and samples the air in the protection zone through a pipe. Simply put, instead of waiting for smoke to reach the detector chamber like point detectors, it speeds up detection by approaching hazardous areas with pipes and drawing the air.

Pipe length and number of the holes must be extracted from the design software of each manufacturer or be selected according to standards.

• distance between hole and wall: 5.1 m
• distance between two holes: 10 m
• Maximum transport time is 120 seconds.

Always you need to consider the local code of practice in your design.

Standards and Classifications:

EN54-20 defines 3 sensitivity classes:

• Class A (very high sensitivity: max 1.1 % obs/m)
  • Clean rooms (such as data centres)
• Class B (Enhanced sensitivity: max 3.3 % obs/m)
  • Critical rooms (such as electrical cabinets, computer rooms etc.)
• Class C (Normal sensitivity: max 5.5 % obs/m)
  • Standard rooms with general fires

VDE-0833-2 defines the application of air samplings considering EN54-20 standard and room height:

• Class A: for room height up to 20m.
• Class A or B: for room height up to 16m.
• Class A, B or C: for room height up to 12m

Applications:

• High ceiling area which installing the point detectors are not allowed.
• Area with sensitive or valuable equipment.
• Area with low accessibility and high sensitivity (e.g. false floors and false ceilings including instrumentation cables)
• Areas where regular spot or linear smoke detectors doesn’t have a suitable performance (high air flow, electromagnetic field, cavities in the ceiling etc.)

Design Types:

• Room protection
• Equipment protection

Parameters affecting the performance of the detector:

• Ambient condition
  • Temperature
  • Humidity
  • Dust
  • Dirt
  • Air streams (Natural, ventilation, HVAC etc.)
  • Air pressure differences
• Altitude of location
• Pipe length, branch, bend and end cap (transport time and response time)

Pipe topologies:

• Single Pipe:
  • I-topology
• Multi-Pipe:
  • U-topology (Symmetric)
  • U-topology (Asymmetric)
  • U-topology (Double)

Air Sampling Supply:

If you supply the air sampling with independent power supply. This power supply must be equipped with the emergency batteries and monitored by central control panel.

Air sampling alarm, fault and reset:

When you use an addressable type of air sampling, you are able to change the ASD settings through the software of the fire control panel or you can reset the air sampling through the central control panel. But when you use input cards (on the addressable loop), you can only send fault and alarm commands to the central panel. For resetting in this case, you need to use an output card in addressable fire alarm panel to send a command to input of reset in the air sampling (if available).

Comparison of several Air Sampling Detectors:

Brand: Siemens

Model: FDA221

• Voltage (V DC): 19 to 30
• Current nominal (mA): 150
• Current alarm (mA): 250
• Dimension (mm): 162x285x120
• Weight (kg): 1.495
• IP: 30
• Air Humidity (%):5 to 95
• Temperature (°C): -20 to 60
• Monitoring Area (m²): Up to 500
• Type: Conv. / Add.
• Pipe Length – Single (m): 30
• Pipe Length – branch (m): 2x25
• Sensitivity (% obs /m): 0.20 to 20
• Relay Output Alarm: 3
• Relay Output Fault: 1
• Approval: VdS

Brand: Siemens

Model: FDA241

• Voltage (V DC): 19 to 30
• Current nominal (mA): 150
• Current alarm (mA): 250
• Dimension (mm): 162x285x120
• Weight (kg): 1.495
• IP: 30
• Air Humidity (%): 5 to 95
• Temperature (°C): -20 to 60
• Monitoring Area (m²): Up to 800
• Type: Conv. / Add.
• Pipe Length – Single (m): 60
• Pipe Length – branch (m): 2x60
• Sensitivity (% obs /m): 0.05 to 20
• Relay Output Alarm: 4
• Relay Output Fault: 1
• Approval: VdS

Brand: Siemens

Model: FDA261

• Voltage (V DC): 19 to 30
• Current nominal (mA): 230
• Current alarm (mA): 250
• Dimension (mm): 262x326x124
• Weight (kg): 2.625
• IP: 30
• Air Humidity (%): 5 to 95
• Temperature (°C): -20 to 60
• Monitoring Area (m²): Up to 3600
• Type: Conv. / Add.
• Pipe Length – Single (m): 2x150
• Pipe Length – branch (m): 800
• Sensitivity (% obs /m): 0.004 to 20
• Relay Output Alarm: 3 (+6)
• Relay Output Fault: 1
• Approval: VdS, EN54-20, EN54-17

Brand: Semens

Model: FDA262

• Voltage (V DC): 19 to 30
• Current nominal (mA): 280
• Current alarm (mA): 300
• Dimension (mm): 262x326x124
• Weight (kg): 625
• IP: 30
• Air Humidity (%): 5 to 95
• Temperature (°C): -20 to 60
• Monitoring Area (m²): Up to 6700
• Type: Conv. / Add.
• Pipe Length – Single (m): 2x250
• Pipe Length – branch (m): 1200
• Sensitivity (% obs /m): 0.004 to 20
• Relay Output Alarm: 3 (+6)
• Relay Output Fault: 1
• Approval: VdS, EN54-20

Brand: AirSense

Model: Stratos Micra 10

• Voltage (V DC): 21.6 to 26.4
• Current nominal (mA): ---
• Current alarm (mA): 250
• Dimension (mm): 145x220x85
• Weight (kg): 1.7
• IP: 50
• Air Humidity (%): 0 to 90
• Temperature (°C): -10 to 60
• Monitoring Area (m²): Up to 750
• Type: Conv.
• Pipe Length – Single (m): ---
• Pipe Length – branch (m): 50
• Sensitivity (% obs /m): 0.3 to 25
• Relay Output Alarm: 2
• Relay Output Fault: 1
• Approval: EN54-20

Brand: AirSense

Model: Stratos Micra 25

• Voltage (V DC): 21.6 to 26.4
• Current nominal (mA): ---
• Current alarm (mA): 250
• Dimension (mm): 145x220x85
• Weight (kg): 7
• IP: 50
• Air Humidity (%): 0 to 90
• Temperature (°C): -10 to 60
• Monitoring Area (m²): Up to 750
• Type: Conv.
• Pipe Length – Single (m): ---
• Pipe Length – branch (m): 50
• Sensitivity (% obs /m): 0.003 to 25
• Relay Output Alarm: 2
• Relay Output Fault: 1
• Approval: EN54-20

Brand: AirSense

Model: Stratos Micra 100

• Voltage (V DC): 21.6 to 26.4
• Current nominal (mA): ---
• Current alarm (mA): 400
• Dimension (mm): 300x220x90
• Weight (kg): 3.8
• IP: 50
• Air Humidity (%):0 to 90
• Temperature (°C): -10 to 60
• Monitoring Area (m²): Up to 1400
• Type: Conv.
• Pipe Length – Single (m): ---
• Pipe Length – branch (m): 100
• Sensitivity (% obs /m): 0.003 to 25
• Relay Output Alarm: 2
• Relay Output Fault: 1
• Approval: EN54-20

Brand: AirSense

Model: Stratos HSSD2

• Voltage (V DC): 21.6 to 26.4
• Current nominal (mA): ---
• Current alarm (mA): 450
• Dimension (mm): 427x372x115
• Weight (kg): 5.2
• IP: 50
• Air Humidity (%): 0 to 90
• Temperature (°C): -10 to 60
• Monitoring Area (m²): Up to 2000
• Type: Conv.
• Pipe Length – Single (m): ---
• Pipe Length – branch (m): 200
• Sensitivity (% obs /m): 0.003 to 25
• Relay Output Alarm: 2
• Relay Output Fault: 1
• Approval: EN54-20

Brand: Xtralis

Model: VLI-880 / VLI-885

• Voltage (V DC): 18 to 30
• Current nominal (mA): 415
• Current alarm (mA): 440
• Dimension (mm): 426.5x316.5x180
• Weight (kg): 6.035
• IP: 66
• Air Humidity (%):10 to 95
• Temperature (°C): -10°C to 55°
• Monitoring Area (m²): Up to 2000
• Type: Conv.
• Pipe Length – Single (m): 120
• Pipe Length – branch (m): 360
• Sensitivity (% obs /m): 0.005 to 20
• Relay Output Alarm: 4
• Relay Output Fault: 1
• Approval: UL, LPCB, VdS, EN54-20

Brand: Xtralis

Model: VLF-250

• Voltage (V DC): 18 to 30
• Current nominal (mA): 220
• Current alarm (mA): 295
• Dimension (mm): 256x183x92
• Weight (kg): 2
• IP: 30
• Air Humidity (%): 5 to 95
• Temperature (°C): -10°C to 55°
• Monitoring Area (m²): Up to 250
• Type: Conv.
• Pipe Length – Single (m): 25
• Pipe Length – branch (m): 2x15
• Sensitivity (% obs /m): 0.025 to 20
• Relay Output Alarm: 2
• Relay Output Fault: 1
• Approval: UL, LPCB, VdS, EN54-20, AFNOR

Brand: Xtralis

Model: VLF-500

• Voltage (V DC): 18 to 30
• Current nominal (mA): 410
• Current alarm (mA): 490
• Dimension (mm): 256x183x92
• Weight (kg): 2
• IP: 30
• Air Humidity (%): 5 to 95
• Temperature (°C): -10°C to 55°
• Monitoring Area (m²): Up to 500
• Type: Conv.
• Pipe Length – Single (m): 50
• Pipe Length – branch (m): 2x30
• Sensitivity (% obs /m): 0.025 to 20
• Relay Output Alarm: 2
• Relay Output Fault: 1
• Approval: UL, LPCB, VdS, EN54-20, AFNOR

Brand: Honeywell

Model: FAAST XS / FSA-5000(A)

• Voltage (V DC): 18 to 30
• Current nominal (mA): 200
• Current alarm (mA): 230
• Dimension (mm): 27.9x22.9x15.9
• Weight (kg): 3.99
• IP: 30
• Air Humidity (%): 10 to 95
• Temperature (°C): 0°C to 38°
• Monitoring Area (m²): Up to 464
• Type: Conv.
• Pipe Length – Single (m): 54.8
• Pipe Length – branch (m): 68.6
• Sensitivity (% obs /m): 0.00095 to 20.5
• Relay Output Alarm: 5
• Relay Output Fault: ---
• Approval: UL, FM

Brand: Honeywell

Model: FAAST XM / FSA-8000(A)

• Voltage (V DC): 18 to 30
• Current nominal (mA): 415
• Current alarm (mA): 465
• Dimension (mm): 33.7x33x12.7
• Weight (kg): 5.26
• IP: 30
• Air Humidity (%): 10 to 95
• Temperature (°C): 0°C to 38°
• Monitoring Area (m²): Up to 743
• Type: Conv.
• Pipe Length – Single (m): 80
• Pipe Length – branch (m): 101.5
• Sensitivity (% obs /m): 00095 to 20.5
• Relay Output Alarm: 8
• Relay Output Fault: ---
• Approval: UL, FM

Brand: Honeywell

Model: FAAST XT / FSA-20000(A)

• Voltage (V DC): 18 to 30
• Current nominal (mA): 465
• Current alarm (mA): 493
• Dimension (mm): 33.8x33.3x19.1
• Weight (kg): 5.4
• IP: 30
• Air Humidity (%):10 to 95
• Temperature (°C): 0°C to 38°
• Monitoring Area (m²): Up to 2601
• Type: Conv.
• Pipe Length – Single (m): 123
• Pipe Length – branch (m): 320
• Sensitivity (% obs /m): 0.00095 to 20.5
• Relay Output Alarm: 8
• Relay Output Fault: ---
• Approval: UL, FM