The challenge of rating energy efficient IAQ management strategies: welcome to IEA-EBC Annex 86

The energy performance of new and existing residential buildings needs to be radically improved to meet ambitious climate change goals and residential buildings are by far the largest component in the total building stock. A central boundary condition in constructing energy efficient buildings is doing so while maintaining a healthy, acceptable and desirable indoor environment. In its mission statement, the IEQ-Global alliance (IEQ_GA) states that Indoor Environmental Quality includes the thermal environment, the indoor air quality, lighting and the acoustic environment that occupants experience in buildings. While ventilation is the main strategy that is adopted for IAQ management, other technologies influencing IAQ (e.g. air filtration) are available as well and a large number of ventilation strategies exist. There is, however, no coherent assessment framework to rate and compare the performance of IAQ management strategies. IEA-EBC annex 86 is therefore developing a performance assessment method for maximizing energy savings while guaranteeing a high level of indoor air quality in terms of comfort and health for the occupants that works across different IAQ management strategies in new, renovated and existing residential buildings.   
By mapping and gathering the existing work on the pollution sources in residential context (including occupant activities and the penetration of outdoor pollution), we are developing a consistent set of metrics that allows us to assess the performance of the various technologies. This includes extending the framework developed in Annex 68 with specific metrics for energy efficiency and particulate matter, explicitly including surface-room interations and HVAC component and controller modeling as well as creating a common methodology for IAQ data sharing among smart devices. By pooling and analyzing the data, the range of conditions in dwellings can be better understood and the most appropriate energy efficient IAQ management strategies can be identified. Ensuring performance over the lifetime of the system, however, requires continuous commissioning of the technical components of the system as well to prevent deterioration of the performance. The application of the assessment method on collected data over time will ensure that the predicted energy efficiency is actually maintained.  
A useful rating method needs to be flexible enough to adapt to the continuously evolving knowledge about the impact of pollutants and the new pollutants 'du jour' that are discovered. The most relevant track that is explored to ensure this flexibility is monetising all impacts. Nevertheless, since monetisation depends on countless assumptions, we are focussing on a reporting guideline that should come with all publications using the method to ensure that the assumptions are clearly reported and the results can be reproduced and updated. This way, we hope to take performance based rating of IAQ strategies one step closer to meaningful day to day implementation.