# The Interplay between Air Quality and Energy Efficiency in Museums, a Review
## 4 Promoting IAQ and EEF in Museums  
To ensure the longevity of the aesthetic value of the exhibits, specific and consistent environmental conditions must be maintained in all buildings housing works of art, whether modern or historical. These conditions must be maintained at all times, whether there are visitors or not. Furthermore, the building must provide visual and thermal comfort, as well as good IAQ for visitors and staff. These objectives necessitate a significant amount of energy, primarily for lighting, heating or cooling, and systems that humidity or dehumidify the atmosphere in the exhibition halls, as well as in the storage rooms and offices. Nonetheless, energy conservation efforts in museums are inevitable [109; 110].  
Ventilation is one of the most important aspects of a museum's IAQ and EEF. The majority of published studies agree that a sophisticated HVAC system with appropriate air filtration can control indoor atmospheric pollutants in the museum, at least to some extent [60; 90]. Other control strategies are also available, as is guidance for museum authorities and curators to prevent the deterioration of works of art due to air pollutants. Every museum can set its own air pollutant concentration targets based on the materials that make up its collections (marble, ceramic, silver, copper, and so on). The relevant literature discusses showcases, standalone air purifiers, and non-invasive treatments for exhibits. However, measures that can be taken to achieve adequate IAQ must take other factors into account, such as resource availability and priority setting.  
Concerning EEF, several studies proposed museum-specific interventions [105; 111; 112]. These include using renewable energy sources, natural daylight lighting and replacing old lighting with non-energy-consuming lamps, mixed mode ventilation, phase change materials, display cases, and other building modifications where possible, such as adding an intelligent facade system with external shading, natural ventilation, and night cooling systems [34; 56; 104; 113; 114; 115; 116].  
In addition, new indices [117], such as life cycle analysis, used to calculate energy consumption and greenhouse gas emissions [118], and \"choosing by advantages\", are being developed to aid decisions for innervations [119].  
Controlling energy consumption as well as IAQ in museums and historical buildings that preserve our world's history remains a challenge. Extensive IAQ and EEF monitoring campaigns must be carried out in each museum, tailored to each special housed collection. Every proposed strategy for improved IAQ, comfort, and climate resilience, as well as the goal of energy savings, should be based on the \"world\" of hard numerical data.  
Finally, in the context of climate change, the Coalition of Museums for Climate Justice has encouraged the museum world to consider _\"their tremendous potential to influence climate action through their programs, research, and advocacy\"_[120; 121]. Museums can contribute to climate change actions, and, because they attract a large number of visitors, these structures can serve as a model for balancing IAQ and EEF [34; 35; 36].  
**Author Contributions:** Conceptualization, G.L.; methodology, G.A.T.; formal analysis, E.K.; investigation, G.L. and G.D.; data curation, G.D.; writing--original draft preparation, G.L.; writing--review and editing, G.L. and S.R.; supervision, S.R. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** No new data were created or analyzed in this study. Data sharing is not applicable to this article.  
**Conflicts of Interest:** The authors declare no conflict of interest.