Indoor carbon dioxide concentrations have been measured and discussed in the context of building ventilation and indoor air quality (IAQ) for more than 100 years. In recent decades they have been proposed as an easy way to evaluate the adequacy of ventilation, even to estimate ventilation rates, as well as an indicator of IAQ. Many of these proposals and applications of CO2 have been technically incomplete if not wrong. The application of indoor CO2 concentrations, as well as their misinterpretation, has increased in light of the COVID-19 pandemic.

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.

A series of Ventilation Information Papers (VIPs) is being developed and published by the AIVC to present national trends and regulations on building and ductwork airtightness. This webinar will explore the building and ductwork airtightness practices in three countries: China, New Zealand, and Japan. Each nation represents a unique regulatory and construction environment, shaped by distinct climate conditions, national policies, and building practices.

As it is now a well-known fact that air leakage can significantly impact the building energy performance, more and more countries are introducing requirements or recommendations on new buildings’ airtightness level in their energy performance regulation. One key aspect to encourage good practice and good airtightness levels in new or retrofitted buildings is to properly include the air infiltration impact in the EP calculation.

Many experts and policy makers may agree that heat pump is one of the most promising technologies for decarbonizing buildings. However, it seems that those engaged in the design and relevant standards of the heat pump systems have not obtained enough information on actual behaviour of the systems in order that we can certainly succeed in reducing energy consumption. For example, do we know how much energy efficiency (EER and COP) of the systems may be reduced under low part load ratio and how low the partial load ratio can be for heat sources?

Many experts and policy makers may agree that heat pump is one of the most promising technologies for decarbonizing buildings. However, it seems that those engaged in the design and relevant standards of the heat pump systems have not obtained enough information on actual behaviour of the systems in order that we can certainly succeed in reducing energy consumption. For example, do we know how much energy efficiency (EER and COP) of the systems may be reduced under low part load ratio and how low the partial load ratio can be for heat sources?

Occupants use windows to control their thermal comfort and indoor air quality (IAQ). However, occupants often have to make a compromise between thermal, acoustic and visual comfort, IAQ and energy use for space conditioning. Moreover, they are not only looking for good indoor environmental quality, but also for their needs for security and privacy.

Ventilative cooling emerges to be a key element in the strategy to meet the cooling demand in buildings while cutting the CO₂ emissions. Ventilative cooling also enhances thermal comfort and mitigates heat stress in buildings. Despite these benefits, the practical adoption of ventilative cooling remains limited among designers. There is still a need for design guidelines and assessment methods in standard weather conditions, extreme scenarios (such as heat waves) and urban environments.

IEA Energy in Buildings and Communities (EBC) research projects are examining building energy codes, exploring data utilization for improving energy efficiency, and investigating air cleaning technologies.

In this webinar, we addressed the opportunities offered by smart ventilation strategies, which include a wide range of systems depending on the type of sensing parameters (CO2, humidity, occupancy, etc.), the type of sensing combinations, the type of installation (centralized/decentralized), the types of control algorithms, etc. We also quantified their potential from and energy and IAQ point of view based on existing and newly developed assessment framework in the annex.