Colbor CF5 Handheld Fog Machine — Mitigation Diagnostic & Air-Leak Tracer

A purpose-built handheld smoke source for mitigation diagnostics

Traditional chemical smoke pencils run out fast, leave residue, and don't give you enough output to see negative pressure across a full slab. The Colbor CF5 is a 40W rechargeable handheld fog machine — originally marketed for photography — that mitigators have quietly adopted as the best portable smoke source on the market for radon and air-sealing work.

Field uses for radon professionals

• Slab penetration leak testing — puff smoke around pipe boots, sump-pit covers, and floor drains while the fan runs. Watch which way the smoke goes — in means seal is good (negative pressure), out means a leak that's bringing radon back in.
• Sub-slab draw verification — introduce smoke at test holes drilled in remote slab areas. Smoke that disappears down the hole confirms pressure field extension; smoke that stays put or rises means the fan isn't reaching that zone.
• Crawlspace encapsulation verification — trace airflow patterns at Stego transitions, foundation-to-plastic joints, and pipe penetrations.
• Pre-mitigation diagnosis — find where radon is currently entering before designing the suction point.
• Customer demonstrations — show homeowners visually how their system is working.

Why this beats a traditional smoke pencil

• 40W output — generates a much larger fog volume than a chemical smoke pencil, useful for spotting weak suction over distance
• Rechargeable — no chemical refills, no running out mid-job
• Remote control — trigger fog from across the room while you watch from the suction-point side
• Adjustable flow + duration — short puffs for precise leak-checking, longer sustained output for area pressure mapping
• Non-toxic, water-based fog fluid — safe for occupied homes (unlike titanium tetrachloride pencils)

Specifications

• Manufacturer: Colbor
• Model: CF5
• Power: 40W, rechargeable internal battery
• Control: On-device + included wireless remote
• Display: Built-in LCD with flow / battery indicators
• Fog fluid: Water-based, oil compatible (use manufacturer-recommended fluid only)
• Form factor: Handheld, portable

What's included

• CF5 fog machine
• Wireless remote
• Flexible output nozzle (precise targeted fog delivery)
• USB-C charging cable
• Fog fluid sample (you'll want extra — we recommend stocking the 240mL bottle)

Pair with the TEC DG-8 Pressure Gauge for the complete radon diagnostic kit: pressure measurement plus visual airflow confirmation.