Webinars

Climate change is leading to increasingly frequent and severe heatwaves, which elevate the risk of human thermal stress in indoor environments. These conditions can make buildings uninhabitable during extreme events and long after they have passed. Therefore, it is crucial to design future-proof buildings and systems that can withstand such shocks and mitigate their impact on human well-being. This performance is known as thermal resilience to overheating.

In many parts of the world, outdoor air quality is so poor that it is better to avoid ventilation with outdoor air. In such cases, the alternative is to substitute ventilation with air cleaning to maintain high indoor air quality. Even when outdoor air quality is good, the use of air cleaning substituting ventilation with outdoor air could reduce the rate of outside air supplied indoors and thereby energy for conditioning (heating/cooling) the ventilation air, filtration and for transporting the air (fan energy) can be saved.

In recent years ventilation system design has seen a shift from design methods based on prescribed flow rates and standard lay outs, towards performance-based approaches which offer opportunities for smart ventilation concepts by considering what ventilation should achieve in terms of indoor air quality and energy efficiency.

There have worldwide been many activities during and after the COVID-19 pandemic to develop guidelines, standards, or new regulations to decrease the risk of cross contamination in the indoor environment. Especially after it had been documented that ventilation plays a significant role in decreasing spreading, several organizations working with ventilation and the indoor environment have been active in leading research and distributing information. The present webinar includes presentations of new guidelines, standards, or regulations from North America, Europe and Asia.

Building airtightness tests are now required or promoted in more and more countries, in particular for residential buildings. However, airtightness tests in high-rise buildings remain particularly challenging and uncommon. In addition to the difficulties of pressurizing any large-volume building and the wind issue that can be more pronounced at height, the stack effect can be particularly problematic.

A smart ventilation system is able to continually adjust itself to provide the desired IAQ while minimizing energy use, utility bills, thermal discomfort and noise. A smart ventilation system is also responsive to e.g., occupancy, outdoor conditions, and can provide information about e.g., IAQ, energy use and the need for maintenance or repair.

A pressurization test with a blower door fan is the most widely accepted and used method to evaluate the airtightness of a building, but it presents some drawbacks. Alternative methodologies have been, or are being, developed and three of them were presented in this webinar:

Significant discrepancies have been observed among European countries, regarding the building and ductwork airtightness trends, attributed to differences between national policies, building practices and climate conditions. In Spain and Latvia, minimum requirements for building airtightness are included in national regulations and Energy Performance calculations, but without a mandatory justification by testing and therefore few new buildings are controlled.

Significant discrepancies have been observed among European countries, regarding the building and ductwork airtightness trends, attributed to differences between national policies, building practices and climate conditions. Minimum requirements for building airtightness are sometimes included in national Energy Performance regulations with a mandatory justification required by testing or applying a certified approach like in France, or with high default values making airtightness testing implicitly mandatory like in Belgium.