IV. System Solutions: Long-Term Prevention and Control Fresh Air Systems Continuously exhausting indoor polluted air and introducing filtered fresh air, maintaining 24-hour air circulation, are currently recognized as the most effective long-term solution. They are particularly suitable for slow-release pollutants such as formaldehyde after renovation (which volatilizes for up to 15 years) and have become mandatory in Europe and the United States. Advantages: Requires minimal frequent operation, can be integrated into smart home systems, and is suitable for all types of homes. Air Purifiers Combining negative ionization, ozone, activated carbon, and HEPA multi-layer filtration technology, they specifically address complex pollution and are suitable for immediate purification needs. However, regular filter replacement is required to maintain efficiency. https://www.renkeer.com/indoor-air-quality/