The fresh air handling unit is an air treatment device dedicated to optimizing indoor air quality. Its core function is to efficiently exchange outdoor fresh air for indoor stale air. Through multi-stage purification and temperature and humidity regulation, it provides a clean, comfortable, and oxygen-enriched air environment for enclosed spaces. Its core operating principle relies on the fan to introduce outdoor fresh air. This air passes through a three-stage filtration system consisting of primary, medium, and high-efficiency filters (optional) to remove impurities such as dust and particulate matter. Subsequently, a heat exchanger is used to recover energy from indoor exhaust air, reducing the energy consumption for fresh air treatment. Finally, the treated clean air is sent indoors, while the stale air containing pollutants such as formaldehyde, CO₂, and VOC is expelled. The core components of the device are sourced from well-known brands in the industry, equipped with comprehensive safety features such as overload protection and frost protection. It can achieve continuous and stable operation 24/7. Additionally, it provides professional customized solutions, installation and commissioning, as well as integrated after-sales maintenance services, offering personalized fresh air solutions for different scenarios.