Single-Arm vs. Dual-Arm Fume Extractors for Soldering Workstations

Can two soldering benches share one fume extractor? A dual-arm unit is a practical option when both hoods can reach their solder joints and capture fumes while both operators are working. With a longer hose, tighter bends, or a cross-draft at one bench, that station may need a different layout or its own extractor.

For electronics assembly and PCB rework, the choice between a single-arm fume extractor and a dual-arm fume extractor starts with the workstations. Map the fume sources, check each duct route, and verify capture at each hood under normal production conditions.

KNOKOO lists a 1.4 m extraction arm for the FED200. The airflow figures above are published system specifications. Use them to compare models during selection, then measure airflow at each station with the actual extraction arms, hoods, filters, and operating settings in place. KNOKOO FES200 and FED200 product comparison

Walk the production line during normal operation and again at peak output. Hand soldering, touch-up work, and soldering iron tip tinning and cleaning may take place in different areas. Larger boards or different fixtures can also shift where the operator solders. Mark the usual solder joints and the farthest points routinely reached on a floor plan, then identify which sources operate simultaneously.

If two operators solder at the same time on one long bench, plan for two capture points. If one operator alternates between two areas, check whether a single extraction hood can be repositioned easily and stay in place at each location.

Record the flux type, soldering frequency and duration, obstructions from fixtures, and operator posture. A bench used for occasional touch-ups and a bench used for continuous multi-joint soldering may need different hood positions and commissioning test conditions.

Bench spacing helps narrow down where the extractor can go. What determines whether each extraction arm will reach is the route from its inlet to the hood's working position. Even adjacent benches may need an indirect route if a parts rack, machine, or service aisle is in the way. Placing the unit between the benches or centrally behind them can shorten both routes and leave operators room to adjust their hoods.

Position each hood near the soldering point and orient it so the plume enters the hood without passing through the operator's breathing zone. Check capture with the shop's normal ventilation running. HVAC supply air, bench fans, and drafts from aisles can all deflect a solder fume plume.

Use a flexible tape measure to follow the proposed route, then move the hood to the farthest regularly used soldering point. Check that the arm stays in position without kinking. Where a bench borders an aisle, verify that people and materials can pass without bumping the arm and that the filters can be removed for service.

Allow room for bends and repositioning when laying out the FED200's 1.4 m arm. Horizontal reach depends on the height of the unit and bench, the duct routing, and how much travel the operator needs to reposition the hood. Check those dimensions before setting the maximum spacing between workstations. KNOKOO FES200 and FED200 product comparison

On a shared fume extraction system, more air generally flows through the branch with lower resistance. A short route can capture the solder fume plume effectively while a longer route around a rack struggles. Changing the resistance of one branch can affect airflow in both branches and shift the operating point of the fan.

For two benches with similar processes and identical hoods, start with comparable duct diameters, lengths, and bends. During commissioning, start with the branch that has weaker capture. Shorten its route where possible, ease tight bends, check the seals at the connections, and reposition the hood near the source. If further balancing is needed, have the commissioning technician confirm which adjustment hardware the unit supports and measure both branches again after any change.

Where the soldering processes or hoods differ, the branches may have different airflow targets. Set each target according to what that workstation needs for effective capture.

At a given fan setting, the delivered airflow depends on the fan's available pressure and the resistance of the installed system. The hood inlet, duct, elbows, fittings, and filters all contribute to pressure loss. At the same duct diameter and airflow, a longer run increases friction loss. Tight bends, abrupt changes in diameter, and flattened flexible duct add resistance. As filters load, airflow may fall at both stations.

For layouts with extended hoses, different hoods, or several bends, give the supplier the actual internal diameter, length, fittings, and hood type for each branch. Ask for airflow and static pressure data for that configuration. Check the pressure loss of each branch at its target airflow and account for the shared sections separately at the combined airflow. If performance data for the proposed configuration are unavailable, trial the installed layout and measure both branches before finalizing the selection.

• Branch airflow is the volume of air moving through a branch per unit of time. Use it to check commissioning targets and establish a maintenance baseline.
• Hood face velocity describes how quickly air enters the hood opening. The hood's size and shape, and the measurement location, affect the reading. The same airflow through two different opening sizes gives different average face velocities.
• Capture at the source depends on hood distance and orientation, workpiece obstructions, and cross-drafts. Even when branch airflow is within target, a hood moved farther away or a plume deflected by a fan can allow fumes to escape.

If both benches lose capture, check the fan setting and filter installation and condition, then check both hood positions and the shop's supply airflow. If only one bench is affected, start with that branch's hose, connections, hood angle, and fixture layout.

With one FED unit, two stations share a fan and filtration system. Plan how both stations will operate around filter changes, servicing, or a unit outage. With two independent FES units, each bench can be adjusted and serviced separately. Allow space, power, and spare filters for both units. If the benches often run on alternating schedules, confirm the approved inlet configuration for single-station operation as well as the setup for running both stations.

Have both operators carry out their usual tasks at the same time. Measure each branch's airflow or record a baseline at a test point with an established relationship to airflow. Check whether each hood captures the plume with operators in their normal positions and the shop ventilation running as usual. If the benches sometimes run individually, verify that mode separately using the inlet configuration approved by the manufacturer.

The commissioning record should include:

1. Hood position at each station
2. Fan setting
3. Filter condition
4. Airflow reading or verified baseline indicator for each branch
5. Production and shop ventilation conditions
6. Observations of fume capture at each hood

Review these records after moving a bench, changing fixtures or hoods, or rerouting a duct. Airflow measurements and plume observations help verify extraction performance. Assess occupational exposure separately for the actual process and site requirements. If the unit returns filtered air to the room, evaluate whether recirculation is appropriate for the contaminants, filter configuration, and applicable occupational hygiene requirements.

Planning fume extraction for an electronics assembly line, a PCB hand-soldering bench, or a rework area? Share your workstation layout, soldering-point spacing, estimated duct lengths and bends, proposed hood positions, process materials, and the number of stations that run at the same time. KNOKOO can help you compare FES single-arm and FED dual-arm configurations and identify what to verify after installation. Contact KNOKOO