1. Choose Your Fan
Select a 120 mm or 140 mm axial PC fan rated at or above your target CFM. Look for static-pressure optimised models from Noctua, Arctic, or Delta. A PWM fan lets you dial in the exact airflow later.
Breathe Easy at the Bench
Stop guessing and start building. Our interactive tool calculates the exact fan CFM, filter surface area, and enclosure volume you need for a custom solder fume extractor that actually works for your specific workspace.
Calculate Your SpecsFume Extractor Spec Calculator
Enter your workspace dimensions and soldering habits to get tailored specifications for your DIY build.
Your Custom Build Specs
Room Volume
–
ft³
Required Fan CFM
–
CFM
Minimum Filter Area
–
in²
Suggested Enclosure
–
in (W×H×D)
Duct Diameter (if ducted)
–
in
These specs assume a single-stage activated carbon and HEPA filter stack. For recirculating units, increase filter area by 30–40%.
From Specs to Solder-Ready
Once you have your numbers, here is how to turn them into a real fume extractor that sits quietly on your bench and keeps the air clean.
2. Size the Filter Stack
Combine a coarse pre-filter (open-cell foam), a HEPA or MERV-13 panel, and a deep bed of activated carbon pellets. The total face area must match or exceed the calculator's minimum to avoid choking airflow.
3. Build the Enclosure
Use 6 mm plywood, acrylic, or 3D-printed PETG. Design a push-through configuration (fan before filter) for better pressure. Add a silicone gasket around the filter frame to eliminate bypass leakage.
4. Position for Capture
Place the intake within 6–12 inches of your soldering tip. A flexible gooseneck or articulating arm lets you reposition it as you move around the board. The closer the capture, the lower the CFM you actually need.
Common Questions
Do I really need a fume extractor for hobby soldering?
Yes. Rosin-core solder flux produces airborne particles and volatile organic compounds (VOCs) that can irritate your eyes, throat, and lungs. Even occasional exposure adds up over years at the bench. A simple extractor dramatically reduces your inhaled dose.
What CFM is enough for a small bedroom workshop?
For a typical 10×10 ft room with 8 ft ceilings, 6–10 air changes per hour works out to roughly 80–130 CFM. Our calculator above gives you the exact number. Most 120 mm PC fans deliver 50–110 CFM, so a pair in push-pull or a single high-speed 140 mm fan often suffices.
Activated carbon vs. HEPA – which filter do I need?
Both. HEPA (or a high-MERV rating) captures the solid particulates – the visible smoke. Activated carbon adsorbs the gaseous VOCs you cannot see but can definitely smell. A stacked combination is the gold standard for recirculating extractors.
Can I vent outside instead of filtering?
Absolutely. Ducting to a window or wall vent eliminates the need for carbon and HEPA filters entirely. You still need a fan with sufficient static pressure to push air through the duct run. Use the duct diameter result from the calculator and keep the run as short and straight as possible.
How often should I replace the filters?
Pre-filters (foam): wash or replace monthly. HEPA: every 6–12 months depending on usage. Activated carbon: every 3–6 months, or when you start noticing odour breakthrough. Mark your calendar – saturated carbon stops working and can even release captured VOCs back into the room.