Air duct cleaning in Leiden

Why access is the key to ventilation ducts in a compact city

On 2,185 hectares of land, Leiden houses 130,108 people in 73,720 households (CBS 2024). That is an average of 1.76 persons per household, a sign of many small dwellings alongside institutions and offices. For duct maintenance, that compactness means: short runs, but little room to get at the duct.

A Eurovent recommendation mentions inspection openings at most 10 metres apart, or no more than two bends of 45 degrees or more between them. Ducts wider than 500 mm need a hatch of at least 500 x 400 mm, and openings on both sides of dampers, coils, MVHR units, silencers, filters and fans. If those hatches are missing, you first fit resealable inspection hatches before you clean.

Duct cleaning Leiden in care and knowledge institutions: which rules count?

With 3,625 establishments in government, education and care, this is a substantial part of the Leiden market. Note one important detail: EN 15780:2025 applies to ventilation systems, but not to industrial, medical and laboratory facilities. For operating theatres and treatment rooms you follow the Dutch guideline on air handling, which requires an air management plan covering technical management, maintenance and periodic checks.

• The SRI is the successor to the WIP guidelines for infection prevention.
• Operating theatre class 1 and 2 require signalling that shows whether the air handling is working properly.
• Where air is humidified, the Working Conditions Decree (Arbobesluit, art. 4.87b) sets out measures against legionella.
• The advice is to assign cleaning and hygiene inspection to different parties.

The full approach per zone is under cleaning ducts in a hospital. For laboratories, you follow the requirements of the installation itself and the management plan, because the general standard excludes them.

Small ducts with tight bends: cleaning with compressed air and camera

In older buildings and small units you come across thin ducts that a brushing machine does not handle well. That is what air lance with camera for cleaning contractors from Danduct Clean is intended for: cleaning with compressed air through a nozzle with a built-in camera and LED lighting, for ducts from 30 mm. The nozzle pulls itself through the duct with the air pressure, takes tight 90 degree bends and comes with 20 metres of hose and a carrying case.

You need a compressor of 700 litres per minute or more at around 10 bar, or nitrogen. The image is black and white through a standard A/V output; you buy the monitor separately. Lamers says it itself: cleaning with an air nozzle was always considered less effective than rotating brushes, but with the camera you see and clean every spot and corner.

Working dust free next to patients, students and residents

In a densely populated municipality you almost always work in a building that stays in use. The basic principle is that every section you clean is under continuous negative pressure. If the extraction unit exhausts inside the building, a HEPA filter that stops 99.97% of particles of 0.3 µm is mandatory. With duct sealing balloon for businesses you close off the duct section and seal the valves in the rooms below it.

A practical working order for a maintenance team:

1. Mark out the zone and inform the users.
2. Seal the valves with foam caps.
3. Close off the duct section with a balloon and connect the extraction unit.
4. Clean from the extraction side towards the open end.
5. Record the result with camera footage and release the zone.

In a building with students or residents, step 1 deserves extra time: a short notice on the door of each affected room explains why a valve is temporarily covered and prevents someone from removing a foam cap halfway through the job.

How do you show that a Leiden duct is clean?

At care and education institutions the client almost always asks for evidence. You show cleanliness after cleaning with a surface comparison or with a gravimetric vacuum test according to NADCA. In German hospital practice, cleanliness is assessed with a dust density measurement by inspectors with VDI 6022 training. Record the before and after photos in the file, together with the method used and the date. That gives the next inspector a point of comparison.

Fictional example: an education building with a laboratory wing

A fictional Leiden education building has lecture halls, offices and a small laboratory wing. The maintenance team splits the work:

• Lecture halls and offices: assessment against EN 15780:2025, cleaning of main ducts with a brushing machine.
• Laboratory: outside the general standard; the requirements from the building's own management plan determine when and how cleaning is done.
• Thin extract pipes in toilet blocks: compressed air with camera, because there are no hatches.

That way each part gets the approach that suits it. This example is fictional and contains no measured values.

Ventilation duct cleaning Leiden and its South Holland neighbours

Lamers has no branch in Leiden, but supplies equipment throughout the country from Zelhem. If you also work in the surrounding municipalities, look at air duct cleaning in Zoetermeer and ductwork cleaning for Leidschendam-Voorburg businesses. The complete overview is under air duct cleaning near me, and you will find all machines under duct cleaning equipment in practice. Request a quote or ask a question about the right combination.