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What are ventilation hygiene services?

Ventilation Hygiene Services (VHS) are essential inspections, testing, and cleaning activities designed to maintain safe, efficient, and compliant ventilation systems. Over time, dust, debris, and microbial contaminants can build up inside ductwork and air handling units (AHUs), reducing air quality, increasing energy consumption, and posing fire or health risks.

At Complii, we deliver complete ventilation hygiene solutions in accordance with BESA TR19, BS EN 15780, and Health & Safety Executive guidance. Our experienced engineers carry out thorough system assessments, cleanliness testing, and deep cleaning to ensure every component of your HVAC system — from air intakes to exhaust — is hygienic, efficient, and compliant.

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Why choose Complii?

How we can help.

Protect your people, property, and business. Here’s why we’re the right choice for ventilation hygiene services.

Cleaner, healthier air

Improved air quality supports occupant wellbeing and comfort, helping to reduce absenteeism and enhance productivity.

Lower fire risk

Removing flammable contaminants and build-up within ductwork significantly reduces the potential for ignition and fire spread.

Improved system performance

Clean ventilation pathways improve airflow, reduce strain on mechanical components, and extend equipment lifespan.

Energy efficiency gains

With less obstruction in your system, fans and AHUs operate more efficiently, helping to lower energy consumption and running costs.

Proven compliance

Our detailed cleanliness testing and reports demonstrate compliance with national standards and support regulatory inspections.

Reduced maintenance costs

Routine cleaning and inspection minimise breakdowns and costly repairs, keeping your systems running smoothly and reliably.

Your questions answered.

Inspections are typically required every 12 months, though frequency depends on the system type, usage, and environment. Complii engineers can help determine the right schedule for your site.
We work in accordance with BESA TR19, BS EN 15780, and Workplace (Health, Safety and Welfare) Regulations 1992, ensuring every service meets the latest compliance standards.
Reduced airflow, musty odours, visible dust around vents, or increased occupant illness may indicate a contaminated system that needs inspection.
Our engineers plan work around your schedule, using specialist equipment to minimise disruption and maintain safety throughout.
Yes, every service includes a detailed post-clean report with measurements, photographs, and maintenance recommendations to support audit and insurance requirements.
Complii provides nationwide coverage, offering consistent, high-quality ventilation hygiene services wherever you’re based.

News & insights

News / November 1, 2025

Introducing Complii: A new chapter in building safety and compliance

For years, navigating the world of building safety and regulatory compliance has felt complicated and fragmented. You might work with one specialist for your fire systems, another for water quality, and yet another for electrical testing. It's a system that creates administrative waste, unnecessary risk, and makes it hard to get a complete, clear picture of your building's health.

News / September 23, 2025

water / September 23, 2025

air / September 23, 2025

PH Water and Air Technologies joins Complii

We are pleased to announce that PH Water and Air Technologies has joined Complii. This addition strengthens our water and air compliance services and further supports our mission to provide trusted, integrated compliance solutions across the built environment.

Insights / September 23, 2025

The benefits of thermographic imaging

Thermographic imaging is a powerful tool for identifying potential electrical faults before they become serious problems. By using specialist thermal cameras, engineers can detect heat patterns that indicate issues such as overloading, loose connections, or failing components.

For businesses, this proactive approach helps reduce risks, avoid costly downtime, and demonstrate compliance with electrical safety regulations.

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Compliance with confidence.

Get in touch for a tailored quotation that fits your site’s needs.