DC4 duct cleaning machine: up to 30 metres in one go

What does the DC4 duct cleaner do in practice?

The core of the DC4 is simplicity. The machine drives a steel spool and drive shaft with a rotating brush at the end. According to Lamers, that light, solid shaft keeps the brush in the centre of the duct, so the brush touches the wall all the way round.

The automatic left to right system changes the direction of rotation at an interval you set yourself. That way the brush works over the duct wall in both directions. You adjust the speed to the duct: slower in delicate material, faster for heavy deposits in steel ducts.

Because the DC4 also handles vertical ducts and 90 degree bends, you need to cut an extra opening less often to reach a run. That saves work in buildings where the ducts run above suspended ceilings or in shafts.

Specifications of the Danduct Clean DC4 at a glance

Source: Lamers and Danduct Clean, reference date 6 October 2026. Request any other technical data from Lamers.

Use this table as a starting point for your own checklist. Put your largest and smallest duct size, your longest run and the type of dirt next to each line, and you can see at once which points need a question to Lamers before you order.

DC4 duct cleaner packages: Medium or Large?

Manufacturer Danduct offers the DC4 in two configurations. Which one fits depends mainly on the length of your runs and how often you encounter stubborn deposits.

If you mainly work in offices with runs up to 20 metres and dry dust, Medium is often a logical start. Cleaning contractors who work in a variety of buildings and want to use the full 30 metres tend to look at Large. Individual brushes in normal, soft and Tynex and the DC4 Sprayer System are available separately.

Which brushes go with the DC4 duct cleaning machine?

The brush determines what you get out. Danduct supplies three types:

• Soft: for delicate ducts. The EPA recommends soft brushes for fibreglass duct board and for sheet metal.
• Normal: the standard for dry dust in supply and exhaust ducts.
• Tynex: more aggressive, for stubborn deposits in sturdy steel ducts.

Choose a brush diameter that matches the duct: too small and you do not touch the wall all round, too large and the brush runs heavily. In square ducts, pay attention to the corners. If in doubt, read how to select brushes for air ducts.

Working with the electric brushing machine in six steps

1. Survey the run. Locate the openings. Eurovent recommends inspection openings no more than 10 metres apart, or with no more than two bends of 45 degrees or more between them.
2. Seal off. Cover valves and diffusers with foam caps and seal the duct section with a balloon.
3. Create negative pressure. Connect an extraction unit and keep the section under continuous negative pressure. If the unit exhausts indoors, use HEPA at 99.97 percent at 0.3 µm. How that works is explained under duct sealing and extraction.
4. Choose shaft and brush. Take the shaft that is just long enough and a brush that matches the diameter and material.
5. Clean. Set the reversing interval and speed, feed in the shaft and let the DC4 do its work. Pull back slowly so the loosened dirt travels towards the extraction.
6. Check. Record the result with a camera inspection or a surface comparison.

The complete process, including reporting, is described in air duct cleaning step by step.

Which buildings and sectors is the DC4 suitable for?

The range of 100 to 600 mm covers most ducts in commercial and public buildings. A few examples where the DC4 is a good fit:

• Offices and business premises: long supply ducts above the ceiling. See ventilation in commercial buildings.
• Schools: the Netherlands Enterprise Agency (RVO) points out that ducts in newly completed schools may be contaminated with construction dust. More under ventilation ducts in school buildings.
• Care: where an air management plan with maintenance and periodic checks is required. Read air duct cleaning in care homes.
• Hotels: vertical exhaust ducts, which according to the manufacturer the DC4 can also handle.

Fictional example: after a school building has been completed, an installer cleans the 315 mm supply ducts. For each run of about 20 metres he sets up negative pressure, cleans with the DC4 and a normal brush, and records with camera images that the construction dust has gone.

DC4, PD4 or Airnozzle: when do you choose the DC4 duct cleaner?

If you work mostly in short sections, look at the compact PD4 duct cleaner. For thin ducts with a camera, compressed air duct cleaning is a useful addition. All machines are side by side when you compare duct cleaning kits.

Spray system and greasy ducts: what should you watch for?

Danduct offers a spray system for the DC4, the DC4 Sprayer System. According to the Eurovent recommendation, dry methods are usually sufficient for supply and general exhaust, but exhaust ducts from commercial kitchens call for wet methods.

For restaurant and catering kitchens there are also grease layer limits. The NVRL and TNO quality mark scheme uses an intervention value of 500 µm of grease and a performance value after cleaning of no more than 200 µm. Whether the DC4 with spray system and Tynex brushes suits your kitchen ducts is best discussed with Lamers beforehand. More background under removing grease from kitchen extraction.

Ready to choose? You can get in touch with Lamers with a quote request, a callback request or a question.