The ventilation principle of the ERV Fresh Air System is to achieve the exchange of indoor and outdoor air through mechanical ventilation, while taking 

into account functions such as air purification, temperature and humidity regulation, etc.‌

1. Basic composition‌

The ERV Fresh Air System is mainly composed of the following core components:

‌Intake fan‌: responsible for introducing fresh air from outdoor into the room.

‌Exhaust fan‌: discharges dirty air from indoor to outdoor.

‌Filter‌: filters particulate matter (such as PM2.5, pollen, etc.) in outdoor air.

‌Heat exchanger (some models)‌: recovers heat/coldness of exhaust air to reduce energy loss.

‌Air duct‌: air circulation duct connecting indoor and outdoor.

2. ERV Fresh Air System Ventilation process

(1) Air intake stage

Outdoor air introduction: The air intake fan draws outdoor air into the system through the air inlet.

Air filtration: Dust, PM2.5, bacteria and other pollutants are removed through multi-stage filters (primary, high-efficiency, activated carbon, etc.).

Heat exchange (optional): If equipped with a heat exchanger, outdoor fresh air exchanges heat with the exhausted indoor air, precooling in summer 

and preheating in winter, reducing air conditioning energy consumption.

Air supply: The treated fresh air is evenly delivered to various indoor areas (such as living rooms and bedrooms) through the air duct.

(2) Exhaust stage

Dirty air collection: Indoor dirty air with high concentration of CO₂, odor, formaldehyde, etc. is collected through the exhaust vent.

Heat recovery (optional): When the exhaust air passes through the heat exchanger, the heat/cold is transferred to the fresh air to reduce energy waste.

Exhaust to the outside: The dirty air is finally discharged to the outside through the exhaust fan.

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3. Ventilation mode‌

Depending on the design, there are two common working modes:

‌Two-way fresh air system: air intake and exhaust are operated simultaneously, forcing air replacement (high-efficiency ventilation, suitable for buildings with good airtightness).

‌One-way fresh air system‌: only air intake or exhaust is operated in one direction (such as positive pressure air supply or negative pressure exhaust), relying on natural ventilation 

through the gaps of doors and windows (lower cost, but lower efficiency).

‌4. ERV Fresh Air System Core functions‌

‌Continuous ventilation‌: Keep indoor and outdoor air circulating to avoid excessive CO₂ concentration.

‌Air purification‌: Filter pollutants and improve indoor air quality.

‌Energy-saving temperature control‌: Reduce air conditioning/heating energy consumption through heat exchange (energy saving rate can reach 60%-80%).

‌Humidity adjustment‌: Some models can balance indoor humidity (such as moisture and dryness prevention).