Air purifier or fresh air system? A comparison of energy consumption and cost in urban China residential buildings

Chinese urban residential buildings face serious indoor air quality problems. Air purification systems(e.g., air purifiers, fresh air systems) that supply fresh air or purify indoor air are widely used in residential buildings to improve indoor air quality.Considering the challenges of energy conservation and emission reduction, it is urgent to guide residents on choosing appropriate air purification systems. The key problem is how to identify the best air purification system with the lowest energy consumption or operating cost. Comparisons of air purification systems have rarely been conducted on the premise that they should deliver air such that the main indoor pollutant concentrations all meet air quality standards. Also ignored in comparisons are the increased filtration resistance caused by dust accumulation on the filter and the cost of filter replacement. In this study, we propose a method to compare residential air purification systems based on energy consumption and total cost, and we provide methods to select air purification systems in China's different climatic regions. We used a standard two-person bedroom as the example, and determined the most suitable(minimum cost or energy consumption) air purification systems for the capital cities of the provinces in Chinese mainland.