Rooftop HVAC unit on a flat industrial roof with cloudy sky in the background.

Natural ventilation systems

Our natural ventilation systems work with your building, helping to harness the wind and heat to create comfortable, healthy environments with low energy demand and maintenance costs.

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Our natural ventilation solutions

Drawing on decades of experience, Colt International can develop natural ventilation schemes that are fully optimised for your building, including automatically opening windows and rooflights, louvres and glazed vents. Our dedicated in-house design team engineers natural ventilation systems for new and existing buildings across a broad range of sectors, helping to manage internal temperatures and air quality whilst minimising operational costs. Where required, we can also develop fully integrated climate and smoke control systems, using natural ventilation technologies to help evacuate smoke from affected areas.

Whether you are looking for a simple solution you can control with a switch, or a fully integrated energy management system which monitors and adapts to internal temperatures, air quality and external weather, we can meet your ventilation needs. All our advanced solutions are manufactured at our UK facility and can be installed, commissioned and serviced by our nationwide network of trained engineers for a seamless end-to-end process.

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What is natural air ventilation?

Natural ventilation, also known as passive ventilation, uses natural forces such as the wind and the natural buoyancy of air to help control conditions within buildings. This can include managing internal temperatures, humidity and air quality. The technologies can either be controlled manually or automatically through building management systems and can significantly reduce operational energy demand, costs and maintenance requirements when compared with powered mechanical ventilation systems. Colt International has been a leading designer, manufacturer and installer of natural air ventilation systems since the 1930s and our systems are used on projects across the country.

Natural ventilation types

There are three basic approaches to natural ventilation, which are commonly used within buildings:

Cross ventilation - This is a wind-driven approach where air is drawn in on one side of a building and flows through the internal space before passing out of an opening on the other side.
Single-sided ventilation - As its name suggests, this is where the space is ventilated through openings on a single side of the building. This is commonly used where cross ventilation is not possible, such as single aspect office rooms and flats.
Stack ventilation - This uses the natural buoyancy of hot air to create a chimney effect where cooler, fresh air is drawn into a space at low-levels whilst the warm stale air is evacuated out through high-level openings such as rooflights.

In practice, our designers may use a combination of these various approaches within different spaces in a building. Where natural ventilation approaches are found to be insufficient, we can adopt a hybrid ventilation approach where we supplement them with mechanical ventilation.

Hybrid Ventilation

Working with Colt

Colt International can support you at each step, from initial concept and design, through to commissioning and maintenance:

Design

We carry out initial consultations to understand your existing building or plans, including internal zoning and specific performance requirements. Our design team then use a variety of approaches, including CFD modelling, to identify the optimal solution.

Manufacture

Once a design is confirmed, we manufacture all our ventilation solutions at our dedicated UK facility and will project manage the production and delivery of your system to the site.

Installation & Commissioning

Our experienced site teams can carry out the complete installation, commissioning and handover. This ensures your system is performing as expected and that you have all the information you need to operate it.

Maintenance

With a UK-wide network of trained engineers, we can keep your system fully and regularly serviced, ensuring continued performance across an extended lifespan.

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Where we work

We have manufactured and installed natural ventilation systems for buildings across a wide range of sectors:

Offices – We can develop systems to suit the various spaces in offices, including glazed vents for lobby areas and louvres for plant rooms.
Industrial facilities – Our natural ventilation systems help to maintain a consistent working height temperature on a number of industrial and manufacturing sites, including the Airbus North Factory.
Healthcare and education –We can develop solutions to help projects meet key industry standards, including Health Technical Memorandum 03-01 (HTM 03-01) and Building Bulletin 101 (BB101).
Warehouse and distribution centres – Our high-level ventilators can provide both stack ventilation and smoke control in large units.
Power generation – Through careful planning, we can deliver effective ventilation whilst limiting noise transmission to the surrounding areas, meeting key planning requirements.

Airbus North Factory

The new £400m Airbus factory based in Broughton, Flintshire covers a massive 46,000 sq metres.

Southmead Hospital, Bristol

Southmead Hospital is expected to be the most sustainable hospital in the UK.

A large office building with "Sky" signage, surrounded by trees and a parking area, set against a clear sky.

BSkyB Building

£233m Harlequin 1 television production centre in Osterley, Middlesex.

Rooftop view showcasing a slanted glass facade and a large dome skylight with visible smoke ventilator systems under a clear blue sky.

Meadowhall Shopping Centre, Sheffield

Colt's involvement in the refurbishment of Meadowhall Shopping Centre.

FAQs

Does Colt offer natural ventilation louvres?

Yes, our range of single, double and triple banked louvres is suitable for use on natural, hybrid and mechanical ventilation systems.

Explore our louvre range

Is natural ventilation the best choice for my building?

The right ventilation system for your building will depend on a variety of factors, including the building height, design and layout, external temperature, noise and pollution, and operating conditions within the building. Our in-house design team will work with you to understand your building and requirements and to develop the optimal solution for your projects, whether it be a natural, hybrid or mechanical ventilation system.

What’s the difference between natural and mechanical ventilation?

Natural ventilation systems (also known as passive ventilation systems) use natural processes such as wind and the buoyancy of hot air to help circulate stale air out of a building and draw fresh air in. In contrast, mechanical ventilation systems use electric systems such as fans or plant equipment to forcefully circulate air in and out of a building. In practice, this means that the energy demand, operational cost and maintenance requirements for natural ventilation systems can be significantly lower than for mechanical ventilation systems.

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