What is a Fresh Air Unit?
A fresh air unit is an air conditioning device that provides fresh air, valves, air outlets, and other components. Its primary function is to introduce outdoor fresh air into the room through the fan, replacing the original contaminated air in the indoor space. This process ensures the indoor air remains fresh and clean. Fresh air fans come in three types: one-way flow, two-way flow, and full heat exchange groups. The first two types have simpler principles, while the full heat exchange fresh air fan incorporates an energy-saving heat exchange system, with a more complex working principle and enhanced effectiveness. 
Three Types of Fresh Air Units
- One-way Flow Fresh Air Units
The one-way flow fresh air unit operates on a “forced exhaust, natural air intake” system. It creates indoor negative pressure through the main engine’s suction, expelling dirty air outside through the air supply duct. To balance indoor negative pressure, fresh air from outside enters the room through pre-installed air intake holes, achieving ventilation. This unit operates with natural air intake, minimal installation pipes, and easy installation.
- Two-way Flow Fresh Air Unit
The two-way flow fresh air unit functions on a “forced exhaust, forced air” system, incorporating forced air supply and exhaust systems. In contrast to one-way flow, it changes the air supply from natural to forced air supply. Fresh air enters the room through the air supply system pipes, while exhaust air is expelled outside through the exhaust system pipes. The two-way flow unit can filter incoming fresh air, providing high-quality ventilation suitable for household and public use.
- Full Heat Exchange Fresh Air Unit
An upgrade from the two-way flow fresh air unit, the full heat exchange fresh air unit adds a full heat recovery system to the main unit. The incoming and outgoing air pass through the heat exchanger, preheating and precooling the air, retaining 70% of indoor air energy. This unit is energy-saving when used with an air conditioner, maintaining indoor air temperature even with significant temperature differences. Ideal for apartments, villas, and offices under 1,000 square meters, it offers high-quality, efficient, and energy-saving fresh air.
Difference Between Fresh Air Unit and Air Conditioning Unit
Difference One
Fresh air units are designed for handling fresh air in large buildings, often used in conjunction with fan coil units. The fresh air unit, together with the fan coil unit, is similar to an air conditioner. While air conditioners have a fresh air outlet, the fan coil unit lacks one, requiring a fresh air fan for proper ventilation.
Difference Two
Fresh air units primarily handle outdoor air, whereas air conditioning units manage air treated by the fresh air unit. Fresh air units can incorporate both return air and fresh air to better adjust parameters such as temperature and humidity.
Difference Three
Fresh air units generally do not bear the heat and humidity load of the air-conditioning area; their main function is to supply fresh air. The ideal state is constant temperature and humidity in the supplied air, which fresh air units typically control.
Difference Four
Air conditioning units handle the heat and humidity load of the air-conditioning area, playing a comprehensive role in air treatment. They focus on controlling temperature, humidity, and air quality in the air conditioning area, with a more complex air treatment process.
Difference Five
Air conditioning units are more complex in terms of air treatment compared to newer fresh air units. Air conditioning units are suitable for large-scale public areas, while fresh air units are often used in smaller spaces where fan coil units are installed.
Both air conditioning units and fresh air units are commonly used, and while different, they can complement each other in functionality. It is recommended to install a fan coil unit in each room simultaneously with a fresh air unit installation for mutual benefit, achieving greater energy savings and comfort.