Natural Ventilation: The importance of air circulation for comfort and energy efficiency

The demand for sustainable practices and ‘green’ buildings has grown substantially, making natural ventilation a star in modern architectural design. This construction technique, which directly dialogues with the local climate and context, offers a way to minimize electricity dependence and consequently reduce greenhouse gas emissions. At the same time, it meets the habitability and comfort needs of a healthy work environment, positioning itself as an ally in the fight against excessive energy consumption and the increase of collective well-being.

Climate changes have led to an increase in electricity consumption for indoor air conditioning. With rising temperatures, the demand for air conditioning, fans, and other cooling systems is becoming increasingly greater.

According to data from NOAA and NASA, global temperatures in 2023 were the highest in the last 144 years, with an increase of 1.4°C (2.52°F) compared to the benchmark average at the beginning of the industrial era (1881-1910). – Link to the article here

As a chain consequence of this, this high demand for air conditioning systems also has significant impacts on the increase of CO2 emissions in the atmosphere as air conditioning can offer necessary relief and reduce the risk of heat-related diseases, but this comes at a cost.

When air conditioning is powered by electricity generated from fossil fuels, CO2 is released, contributing to the greenhouse effect. In addition, air conditioners emit heat to the outside, contributing to the heat island effect in urban areas. The wrong disposal of old air conditioners can also release harmful gases that retain heat.

A study conducted by Climate Central demonstrates that air conditioning consumption in U.S. homes is expected to increase by 59% by 2050, surpassing the projected growth of 17% in commercial spaces, as follows:

• It is estimated that air conditioning consumption will increase by 59% in U.S. homes by 2050.
• The energy consumed by fans represents 25 to 35% of electricity consumption in non-residential buildings.
• In the United States, 87% of all buildings have air conditioning.
• Global sales of air conditioning units are increasing by 13% per year.
• In India and China, the energy demand for summer cooling exceeds supply.
• The demand for electricity for air conditioning in China will be higher than in the United States by 2020.

These data show the need to rethink the way we build and adapt our buildings, making them resilient to both the current climate and future projections of climate change.

In this context, natural ventilation plays a crucial role in the comfort and energy efficiency of environments. This concept involves the circulation of air naturally, without the need for mechanical air conditioning systems. In addition to providing a more pleasant environment, natural ventilation also brings significant benefits in terms of energy savings.

What is Natural Ventilation?

Natural ventilation encompasses the intentional use of building openings, such as doors, windows, skylights, and other elements, to allow the circulation of air inside buildings, without the need for electronic equipment. This subtle technique uses natural forces, such as wind and thermal differences, to create an air flow with the purpose of renewing and improving the quality of indoor air. Diverging from forced ventilation systems that require external energy to move the air, natural ventilation promotes a continuous alternation of indoor air with the outdoors in a self-sustainable way, offering an efficient strategy to reduce energy consumption and maintain a healthy indoor environment.

It differs from mechanical ventilation, which involves the use of fans and ducts to drive the air. Such a system consumes electricity and often requires regular maintenance, while natural ventilation takes advantage of available environmental resources at no additional cost and with minimal maintenance. Intelligent design and strategic location of openings provide the operating principles for this ecologically and economically advantageous approach. Thus, it contributes to the well-being of occupants and to physical structures more integrated with the surrounding natural ecosystem.

The Relationship between Architecture and Environment

Harmonious Integration: Incorporating natural ventilation in buildings reflects a commitment to environmental preservation. This method takes advantage of natural resources, such as wind dynamics and thermal differences, to foster air flow and facilitate the air conditioning of internal environments. This approach minimizes dependence on mechanical cooling and heating systems, which are notorious energy consumers and emission generators.

Maximized Efficiency: The careful implementation of natural ventilation design reduces the carbon footprint of buildings. In addition, by operating without the need for electricity, these systems not only cut operating costs but also perpetuate optimized energy performance throughout the life of the buildings.

Environmental Support: By integrating these systems, architects and engineers play an active role in global sustainability. Natural ventilation aligns with sustainable development strategies, contributing to the achievement of ecological goals and to the mitigation of climate change by reducing the demand for non-renewable resources.

Advantages of Natural Ventilation

The use of natural ventilation in buildings goes beyond mere air exchange, playing a key role in optimizing energy consumption. The fluidity of air facilitated by natural ventilation methods implies a significant reduction in the need for artificial cooling and heating systems, reflecting in a notable energy savings. The flow and renewal of air without the use of electrical equipment is more than an economic response; it is the harmonization of physical comfort with environmental awareness.

Moreover, the thermal comfort provided by these systems is an unquestionable attribute. The natural circulation of air induces the stabilization of internal temperatures, keeping the environments in pleasant conditions and free from the annoying oscillations caused by mechanical devices. This is an advantage especially valued in climates that experience thermal variations throughout the day or year.

In addition, the quality of air received by the occupants of the spaces is exponentially improved. Natural ventilation performs the dilution of internal pollutants, warding off contaminants and contributing to a healthy environment. This continuous air exchange prevents stagnation, which is often associated with the appearance of molds and the proliferation of fungi, safeguarding the respiratory health of individuals.

So we can categorize the advantages of natural ventilation into four essential points, which are as follows:

1. Provide fresh air: It is essential to provide fresh air to meet people’s physiological needs and remove unpleasant odors. A flow rate of 8 to 10 liters per second per person is recommended to ensure a healthy and comfortable environment (CIBSE Guide A, CIBSE AM10, and BS EN 13779).
2. Convection cooling: In environments where cooling is needed, like large rooms or spaces with many people, it is important to have a large volume of air circulating to maintain the right temperature. A flow rate of approximately 50 to 100 liters per second per person is recommended in these situations (CIBSE Guide A, CIBSE AM10, and BS EN 13779).
3. Physiological cooling: The movement of air also plays an important role in the physiological cooling of people. The increase in air circulation promotes heat loss by convection and skin evaporation, helping to maintain a healthy body temperature.
4. Reduction of carbon emissions and costs: In addition to the benefits for people’s comfort and health, the proper circulation of air can also contribute to the reduction of carbon emissions, as well as to the reduction of capital and operating costs. By designing efficient and sustainable ventilation systems, we can minimize energy consumption and promote environmental sustainability.

We have a more explanatory post about the principles and design strategies for natural ventilation by clicking here.

Compliance and Occupational Health

By implementing natural ventilation solutions in their facilities, companies meet the guidelines established by Guidance Standards and Building Regulations.

Natural ventilation, by promoting the replacement of confined air with fresh air from the outside, ensures a significant reduction of contaminants present in closed spaces. In this way, it contributes to the decrease of health risks related to respiratory problems and allergies, providing a healthier and more productive work environment. In addition, by favoring the regulation of temperature and humidity without resorting to non-renewable energy resources, companies obtain advantages for both the well-being of the workers and the sustainability of their operations.

Ensuring an environment with fresh air, adequate cooling, and energy efficiency is essential for people’s well-being and for the preservation of the environment. By considering these aspects in construction projects and ventilation systems, we can create healthier, sustainable, and comfortable spaces for everyone.

Positive Financial Impact of Natural Ventilation

The implementation of natural ventilation emerges as a financially astute strategy for companies. By reducing the dependence on electric air conditioning systems, there is a notable reduction in energy costs. This savings extends throughout the building’s life cycle, as non-mechanical ventilation solutions do not depend on electricity to operate, leading to a more favorable energy balance.

Additionally, structures that take advantage of natural ventilation tend to accumulate fewer maintenance expenses. Mechanical ventilation systems, with their moving parts and constant need for review, see these costs virtually eliminated when replaced by natural methods. This not only simplifies operational management but also eases the budget allocated to the conservation of air conditioning systems.

By adopting natural ventilation, organizations also plant the seeds for lasting benefits. By favoring a work environment with better air quality and thermal comfort, workers’ health is protected, which can result in fewer days of work absense due to respiratory diseases and other conditions related to unfavorable indoor climate. In this way, the initial investment in ventilation is offset not only by direct savings but also by a healthier and more productive workforce in the long term.

Breathing a Sustainable Future

The role of natural ventilation in designing more sustainable and productive architecture has never been so prominent. With the advancement of environmental discussions and the increase in awareness about the carbon footprint, companies and organizations visualize a horizon where buildings breathe in harmony with the environment, conjuring spaces that not only house human activities but also promote health and well-being.

This approach is aligned with sustainable development goals and presents itself as a legacy for future generations. Through the implementation of refined and eco-efficient ventilation strategies, a balance is achieved that meets the operational needs of built spaces, while reducing energy consumption. The construction that adopts these principles shows not only respect for the planet but also a smart investment with measurable returns in terms of reducing operating costs and improving the quality of life of its occupants.

Going forward, buildings armed with these ventilation solutions will be seen as a standard in the construction industry, true pillars of a corporate ethic that prioritizes environmental responsibility. Access this fresh air current flowing through green initiatives, and watch workplaces transform, not only more energy efficient, but also as healthier and more productive spaces.