Ventilation mode with outdoor air intake FRESH AIR SYSTEM in split-type air conditioners
Purpose and operating principles of air conditioners with supply ventilation
The fresh air supply function is a technological solution integrated into the air conditioning system that enables air exchange between the indoor space and the outdoor environment. Unlike traditional air conditioners operating in a closed recirculation loop, units with a supply function are additionally equipped with an air duct through which outdoor air enters the room. Before delivery, the air undergoes multi-stage purification and temperature treatment. This ensures optimal oxygen levels, reduces carbon dioxide concentration, and generally improves the indoor climate in enclosed spaces.
Applications of the ventilation function (breather)
The fresh air supply function 
is particularly relevant in spaces with limited or no natural ventilation. Such locations include apartments with sealed windows, office and public buildings with high occupancy density, as well as medical and educational institutions. In private houses and cottages without centralized ventilation, supply air conditioners help compensate for air shortages without the need to open windows.
Design and operation of the FRESH AIR system
Air conditioners with supply ventilation include the following structural components: outdoor air intake, filtration system, heat exchanger, and distribution unit. In operation, outdoor air is drawn in through a dedicated channel, passes through filters (including fine filters), is heated or cooled as needed, and is then evenly distributed throughout the room. Some models allow independent operation of the cooling system and air supply, enhancing climate control flexibility.
Types of systems with fresh air supply function
There are several types of climate systems that implement outdoor air supply:
- Duct systems — initially designed to operate with air ducts, they provide high air supply volumes and even distribution across multiple rooms. They require complex installation and highly skilled technicians.
- Wall-mounted split systems with supply option — equipped with additional modules or air intake elements. Their fresh air performance is limited, making them suitable only for low-occupancy areas.
- Monoblock units — mainly implemented as window models and provide outdoor air intake through built-in openings. They have higher noise levels and limited capacity.
Advantages and disadvantages of air conditioners with supply ventilation
The key advantages of systems with a fresh air supply function include:
- Ensuring continuous air exchange without opening windows;
- Purification of incoming air from dust, allergens, and harmful impurities;
- Combining cooling/heating and ventilation functions in a single unit;
- Possibility of operation at any time of the year.
Disadvantages include:
- Higher equipment cost compared to basic models;
- Requirement for professional installation and air duct routing (in duct systems);
- Limited air supply volume in wall-mounted models;
- Increased noise level in certain modifications.
Selection criteria
When choosing an air conditioner with an outdoor air supply function, consider the following:
- Supply capacity — the required air volume is calculated based on the number of occupants (approximately 30 m³/h per person);
- Presence of filters — systems with multi-stage filtration (including HEPA filters) are preferable for allergy sufferers and medical facilities;
- Noise level — the lower the noise, the more comfortable it is for residential use;
- Temperature range — units with an extended outdoor temperature range are suitable for year-round operation;
- Additional functions — self-cleaning modes, remote control, personalized climate settings, and other options improve convenience.
Features of operation in the winter season
In cold weather, the efficiency of the fresh air supply system may decrease. The absence of a preheating function for the supply air can cause a drop in indoor temperature. Some models provide heating by placing the intake valve in the heat exchanger zone; however, when temperatures drop significantly, the effect may be insufficient. Therefore, in winter, it is recommended to use the air supply function only in combination with the heating mode.
Conclusion
Air conditioners with a fresh air supply function are multifunctional units capable of maintaining the indoor climate not only by regulating temperature but also by ensuring quality air exchange. Such systems are particularly relevant in sealed spaces with limited natural ventilation. When selecting equipment, it is important to consider a combination of factors: type of installation, supply air volume, filtration level, noise characteristics, and installation specifics. Despite higher cost and installation complexity, these systems provide more comfortable and healthier living and working conditions.
Related articles:
Air conditioners: main functions and modes
iFEEL function in air conditioners
Anti-FUNGUS function in air conditioners
iFAVOR function in air conditioners
TIMER function in air conditioners
SWING function
Automatic mode selection SMART
ECO function in air conditioners
Limited power mode GEN, GENERATOR
User manuals user for climate remote controls |