Traditional air conditioners, also known as split systems or window units, typically do not bring in fresh air from outside. Their primary function is to recirculate and cool the indoor air in a closed-loop system. They cool the indoor air by removing heat and moisture from the room, then recirculate the cooled air back into the same space.
However, to maintain indoor air quality and ensure proper ventilation, buildings usually have separate ventilation systems. These ventilation systems are designed to bring in fresh outdoor air and exhaust stale indoor air. The ventilation system may operate independently or be integrated with the air conditioning system.
Mechanical Ventilation System: A mechanical ventilation system is specifically designed to provide controlled and continuous fresh air exchange from outside. It works independently from the air conditioner and usually consists of fans, ducts, and sometimes heat recovery systems.
Air Handling Units (AHUs) with Fresh Air Intake: In some commercial HVAC systems, especially in larger buildings, there are air handling units (AHUs) that can handle both cooling and ventilation. These AHUs can include fresh air intakes to bring outdoor air into the building while also cooling or heating it before distributing it throughout the indoor space.
Dedicated Outdoor Air Systems (DOAS): Dedicated Outdoor Air Systems (DOAS) are another type of ventilation system commonly used in commercial buildings. DOAS focus solely on bringing in fresh outdoor air and treating it separately from the cooling or heating process. They dehumidify and condition the outdoor air before distributing it to the indoor spaces, promoting better indoor air quality.
It's essential to note that while some HVAC systems can provide fresh air intake, traditional residential air conditioners usually do not have this capability. In residential settings, homeowners can open windows and doors to let in fresh air manually, but this may affect the cooling efficiency of the air conditioner, especially in hot weather. Some modern residential HVAC systems may have features that allow limited fresh air intake, but these are typically not as prevalent as in commercial buildings with dedicated ventilation systems.