Bioclimatic ventilation aims to take advantage of the natural environmental conditions and the characteristics of the building itself, promoting thermal comfort. Within these strategies, bioclimatic atriums play a key role in multi-storey buildings. They are an ideal option for providing natural light, facilitating air circulation and acting as intermediate spaces between the outdoors and conditioned indoor areas.

In addition, in certain buildings, it may be beneficial to complement passive strategies with efficient air movement systems, such as HVLS fans. This solution allows the operation of the space to be adapted to actual conditions of use.

What is bioclimatic ventilation?

Bioclimatic architecture aims to adapt buildings to the climate and make use of available natural resources before relying on active climate control systems.

The objective of having adequate bioclimatic ventilation is to ensure that the building’s own configuration helps moderate indoor conditions. This reduces energy demand and improves the performance of climate control systems.

Each project has its own requirements. For this reason, strategies are selected by evaluating different factors, such as:

  • Building orientation.
  • Height of the space.
  • Layout of the different floors.
  • Architectural obstacles.
  • Outdoor temperatures.
  • Solar radiation and exposure.
  • Prevailing winds.
  • Air distribution throughout the space.
  • Temperature differences between day and night.
  • Thermal transmittance of glazing.
  • Position and size of openings.
  • Existing climate control systems.
  • Occupancy and operating hours.

Climate control solutions that can form part of a building’s bioclimatic design include:

  • Natural and cross ventilation.
  • Atriums and intermediate spaces.
  • Solar protection and control.
  • Use of solar radiation in winter.
  • Thermal mass of materials.
  • Solar chimneys.
  • Night ventilation.
  • Vegetation-based solutions and shading.

The Institut Català d’Energia (ICAEN), for example, includes various strategies of this type in its publications on bioclimatic architecture.

The role of atriums in bioclimatic architecture

An atrium is a tall interior space that typically connects different floors or areas of a building.

In addition to serving as a circulation space or providing natural light, it can form part of the project’s energy strategy. When properly designed, it can act as a transition zone or buffer space between the outdoors and conditioned indoor areas, helping moderate the thermal conditions of adjacent spaces.

Depending on the time of year and the characteristics of the project, incorporating atriums into bioclimatic architecture can contribute to the building’s thermal performance in different ways.

During colder months, solar radiation entering through glazed surfaces can increase the temperature of the atrium and reduce the temperature difference between the outdoors and indoor spaces. In this way, solar heat gains can be used to contribute to the thermal performance of the building.

In tall atriums, some of the warm air can accumulate near the roof due to thermal stratification, creating temperature differences between upper levels and occupied areas. HVLS fans can promote thermal destratification by redistributing this heat towards lower areas.

Combining HVLS fans with bioclimatic atriums can provide several benefits in winter:

  • Better temperature distribution: Reduces temperature differences between lower and upper areas.
  • Improved use of heat: Redistributes some of the energy accumulated at height towards occupied areas.
  • More consistent comfort: Helps maintain more stable thermal conditions throughout the space.
  • Controlled air movement: The fans operate at low speeds to avoid uncomfortable draughts affecting occupants.

To define the most appropriate strategy, key building characteristics such as orientation and glazing thermal transmittance must be assessed, along with other relevant factors.

During warmer months, the objective is to limit excessive solar radiation and facilitate the removal of accumulated heat. In glazed atriums, solar radiation can quickly increase the thermal load of the space and encourage warm air to accumulate beneath the roof. This affects not only the atrium itself but also adjacent residential units, offices and other areas.

To control this overheating, elements such as solar shading, suitable glazing, operable openings and natural ventilation must be combined. When air inlets are located in lower areas and outlets at higher levels, the so-called stack effect can occur: warm air rises and escapes through the upper openings, while outdoor air enters through the lower areas.

When this natural air movement is insufficient, HVLS fans can complement the strategy and provide several benefits:

  • More even air distribution: Helps reduce areas with limited air circulation within the atrium.
  • Support for heat removal: Can help direct air towards openings or extraction points.
  • Greater thermal comfort: Air movement over occupants promotes sweat evaporation and improves thermal comfort.
  • Support for climate control: Allows air movement, natural ventilation and HVAC systems to be combined according to the building’s requirements.

It is important to note that HVLS fans do not directly reduce air temperature in the same way as a cooling system. Their function is to generate air movement and improve comfort, while their integration with natural ventilation, openings and other building systems depends on the characteristics of each project.

Bioclimatic ventilation, atriums and HVLS fans: Complementary strategies

In bioclimatic atriums, an efficient strategy can combine passive and active solutions to adapt the thermal behaviour of the space to changing conditions. In this context, HVLS fans are designed to generate wide, gradual air movement across large areas. This makes it possible to develop specific solutions for atriums, covered courtyards and other tall spaces without the need to install numerous smaller fans.

Their operation can also be adapted to the building’s requirements:

  • Seasonal operation: Different strategies for winter, summer and transitional seasons.
  • Speed regulation: Allows air movement to be adjusted according to thermal conditions and occupancy.
  • HVAC integration: Can operate in coordination with heating and cooling systems.
  • Adaptive control: Allows fan operation to be adapted to the building’s requirements.
  • Night ventilation: Can complement free cooling strategies when outdoor conditions are favourable.

For this reason, the incorporation of HVLS fans should be considered part of the building’s overall strategy rather than an isolated solution. Their installation can be assessed in both new construction and renovation projects, defining the location, diameter, number of fans and operating strategy according to the characteristics of each project.

ventilazione-bioclimatica-negli-atri

Night Ventilation and the Use of Thermal Mass

In climates where temperatures drop significantly at night, night ventilation or free cooling can be used to remove some of the heat accumulated during the day. This strategy is particularly interesting in buildings constructed with materials capable of storing thermal energy.

During the night, when outdoor air is cooler than indoor air, it can be used to help reduce the temperature of walls, floor slabs and other elements with high thermal mass. As a result, the building starts the following day with a lower thermal load.

In certain projects, air movement systems can complement this strategy by helping outdoor air reach different areas of the atrium more evenly and facilitating the removal of accumulated heat.

Ventilation control and automation

One aspect that can significantly improve the performance of a bioclimatic strategy is adapting equipment operation to the building’s actual conditions.

Ventilation does not always need to operate with the same settings. Information from sensors and management systems can be used to adjust operation according to variables such as indoor and outdoor temperatures, occupancy schedules and seasonal conditions.

Furthermore, when the building has a centralised management system with smart control, fans can be integrated into a coordinated climate control and air movement strategy. This allows different operating modes to be established for winter, summer and transitional seasons, avoiding the use of equipment in the same way regardless of existing conditions.

Designing the atrium as part of the building’s energy system

In terms of building energy efficiency, an atrium can play a key role, but its performance will largely depend on whether its thermal behaviour is studied from the earliest stages of the project. It is also important to assess how the atrium will interact with adjacent spaces and the building’s mechanical systems.

This approach is becoming increasingly important in architectural design. A recent example is the evolution of regulations governing courtyards and light wells in Barcelona, which aim to facilitate larger interior spaces and improve aspects such as natural lighting and ventilation in residential buildings.

The regulations also consider the possibility of incorporating bioclimatic atriums capable of taking advantage of natural phenomena to contribute to the building’s thermal performance. Although this is a local initiative, it illustrates a trend applicable to many markets: integrating environmental conditions into the design from the outset, rather than addressing all requirements later through mechanical climate control.

soluciones-bioclimaticas-en-atrios

Bioclimatic ventilation in real projects

The integration of bioclimatic atriums and air movement systems can be applied to very different types of buildings, from large public facilities to residential projects.

The following projects demonstrate how these strategies can be adapted to different needs, scales and uses while maintaining the same objective: improving air management and the building’s thermal comfort.

ventilazione-bioclimatica-negli-atri

Multi-family housing: Project with Calaf Constructora

These solutions can also be applied to residential projects. At Magnovent, we have recently participated in social housing developments in Barcelona in collaboration with Calaf Constructora, incorporating air movement systems in large-volume interior spaces.

City of Justice of Valencia: Managing large air volumes

The City of Justice of Valencia is an example of a tall building where air management is particularly important. In this project, completed in 2025, Magnovent installed 8 HVLS fans at a height of 30 metres, with fan diameters of 7.30 metres, to promote air circulation in a large-volume space.

The installation demonstrates how HVLS systems can be integrated into large atriums and institutional spaces to improve air distribution and complement the building’s climate control strategies.

These two examples demonstrate how ventilation and air movement strategies in bioclimatic atriums can be adapted to very different building types, scales and uses, from large public buildings to multi-family housing.

Solutions for bioclimatic atriums with Magnovent

At Magnovent, we analyse each project to define the most suitable air movement solution for each atrium, taking into account its geometry, height, use, existing installations and thermal behaviour.

If you are designing a new bioclimatic atrium or want to improve the performance of an existing one, contact our team and we will work with you to identify the most suitable solution for your project.

Frequently asked questions about bioclimatic ventilation and HVLS fans

It is a multi-storey interior space designed to contribute to the building’s environmental performance through strategies such as natural lighting, solar heat gain, ventilation or the creation of an intermediate thermal zone.

A large glazed surface can increase solar heat gains and encourage heat accumulation beneath the roof, particularly during warmer months. If the available ventilation is insufficient, it can also increase the thermal load of the spaces surrounding the atrium.

No. Both strategies can complement each other. Natural ventilation depends on the building’s design and outdoor conditions, while fans allow air movement to be controlled when these conditions alone do not produce the desired results.

Yes. Air movement over occupants promotes sweat evaporation and can improve thermal comfort. It can also help reduce areas of stagnant air and complement natural ventilation strategies when the building’s configuration allows it.

Yes, whenever possible. Incorporating them from the design stage makes it easier to assess mounting points, heights, existing installations, obstacles and airflow patterns. However, solutions can also be considered for existing buildings and renovation projects.

HVLS fans can be integrated both architecturally and technically. In atriums where design plays an important role, different configurations and finishes can be considered to visually adapt the equipment to the space.

In addition, depending on the installation, they can operate alongside HVAC systems and building management systems to adapt their operation to thermal conditions, occupancy schedules or different seasonal operating modes.

There is no standard configuration. The volume, height, geometry, glazed surface area, openings, climatic conditions, occupancy and existing installations must be analysed before determining the number, size, position and operating strategy of the fans.

Contact our team, tell us about your project and we will assess the most suitable ventilation solution for your building.