IEA-EBC Annex 78 Supplementing Ventilation With Gas-phase Air Cleaning, Implementation And Energy Implications
Chair(s): Bjarne Wilkens Olesen (ICIEE, DTU.SUSTAIN, Denmark), Pawel Wargocki (ICIEE, DTU.SUSTAIN)
There are an increasing number of publications in many countries related to air cleaning and increasing sales of gas-phase air cleaning products. This introduces a demand for verifying the efficacy of air cleaning on indoor air quality for comfort, well-being, and health. It is thus important to learn whether air cleaning can supplement ventilation by improving air quality, i.e. whether it can partly substitute the ventilation rates required by standards. Also, the energy impact of using air cleaning as a supplement to ventilation needs to be estimated. This has been topics, which researchers from several countries have looked at in Annex 78 during the period 2018-2025
The session will present of the results of Annex 78. Several studies on energy performance and impact on indoor air quality of gas-phase air cleaning technologies were conducted during the annex. This has resulted in several papers, seminars and reports. Finally a test method is proposed for testing the Clean Air Delivery Rate (CADR) using perceived air quality as a measure.
Presentations of the Workshop
1. Introduction And Major Achievements Of Annex 78
Bjarne Olesen
ICIEE, DTU.SUSTAIN
The worldwide use of gas-phase air cleaning has been growing in recent decades. There is little information, however, on the performance of gas-phase air cleaners, especially on whether they can substitute ventilation, whether there are any potential risks associated with their use, and how their use contributes to energy savings and reduced carbon footprint. Moreover, there are, at present, no standards that allow systematic and repeatable benchmarking for the performance of gas-phase air cleaners. These challenges set out the Annexe 78 direction, which provided the answers on the energy benefits of using gas-phase air cleaners, how the air cleaners can substitute ventilation, standards for testing air cleaners, and the long-term performance of gas-phase air cleaners.
2. Gas Phase Air Cleaning Technologies And Related Models
Jianshun Zhang
University of Syracuse, USA
This talk introduces a state-of-the-art review of portable gas-phase air-cleaning technologies on non-industrial premises. The paper is based on a review of scientific papers. The opportunities and limitations regarding the available techniques are discussed. The talk addresses gas adsorption filtration, including adsorbent media, photocatalytic oxidation, air ion generators, ozone generators, and plant-based biofiltration. Knowledge from both experimental and modelling research is included to assess the performance of the various air cleaning technologies and their impact on indoor air quality.
3. Energy Performance Of Gas-Phase Air Cleaning Technologies
Alireza Afshari
AAU, BUILD
IEA EBC Annexe 78 addressed the challenge of balancing indoor air quality (IAQ) and energy efficiency in buildings by exploring the application of gas-phase air cleaning technologies. This task focused on how integrating gas-phase air cleaners and, thus, increasing indoor air recirculation can minimise heating and/or cooling requirements while upholding acceptable IAQ standards. Furthermore, the clean air effectiveness (CAE) is recommended as a new key performance indicator (KPI), which can be used to include the energy benefits of substituting the outdoor air supply of air cleaners in the design process of ventilation systems.
4. A Test Method For Air Cleaning Technologies That includes Perceived Air Quality As A Measure Of Performance
Pawel Wargocki1, Shin-ichi Tanabe2
1ICIEE, DTU.SUSTAIN, 2Waseda University
A method for testing gas-phase air cleaners using sensory assessment was examined. This study generally followed methodologies proposed by the ISO 16000-44 standard, and the results of this study validate and support them. More testing is still necessary before its full application in practice.
The proposed method includes two phases. The results confirmed that Phase 1 effectively eliminates the air cleaners that do not improve air quality. Phase 2 is necessary since it provides detailed information on the actual performance of air cleaners in the form of Clean Air Delivery Rate (CADR). The recommended ventilation rates in ISO 17772-1/2 may then be reduced by the CADR of a gas phase air cleaner