Evaluation of Ventilation Configurations for Icelandic Conditions

Sammanfattning

Ensuring healthy indoor air quality (IAQ) and preventing mold growth is critical in Icelandic residential buildings, where cold climate, airtight construction, and limited ventilation can compromise occupant well-being and building durability. At the same time, improving energy efficiency is essential, even in a country with mostly renewable energy sources. This study examines how different ventilation configurations, including natural and mechanical ones, will affect five evaluated parameters: energy consumption, IAQ, thermal comfort, mold growth, and cost. This study was conducted through a simulation approach to evaluate five ventilation configurations: No ventilation, natural ventilation, natural ventilation with night ventilation, constant air volume ventilation (CAV), and variable air volume ventilation (VAV) across three apartment types. Two simulation software were used in this study, IDA ICE and WUFI.Results showed that mechanical ventilation consistently ensured good IAQ and mitigated mold risk. The VAV systems had lower energy consumption and operational cost than the CAV system. All ventilation configurations had exhibited similar levels of thermal discomfort based on average PPD values; however, natural ventilation scenarios had more hours during the year within the acceptable thermal comfort range, based on PMV. In contrast, the absence of ventilation resulted in critically poor IAQ, and mold growth would be inevitable. Natural ventilation had varying and inconsistent IAQ and could not eliminate the risk of mold growth. The evaluation of the ventilation configurations showed clear trade-offs. Despite higher costs, mechanical ventilation, notably VAV ventilation, offered the most reliable results across all parameters. Natural ventilation may be an attractive option for its simplicity and affordability, but it’s highly dependent on occupant behavior and favorable outdoor conditions. It may still be viable in certain scenarios, but it cannot guarantee a healthy indoor environment without careful design and occupant engagement. Mechanical ventilation offers consistency, reliability, and a healthy indoor climate, balancing sustainability.