Central air conditioning systems can be designed to either recirculate indoor air or incorporate fresh air ventilation. The specific setup depends on the type of system and the preferences or requirements of the building.
- Recirculation: In a typical central air conditioning system, the primary function is to cool or heat the indoor air. These systems recirculate the air within the building by pulling it through a return duct system, passing it through the air handler, and then redistributing it through the supply ducts. The air is conditioned by passing it over coils where it is cooled or heated before being sent back into the living spaces.
During the recirculation process, the air is filtered to remove dust, pollutants, and allergens. The filtered air is then conditioned to the desired temperature and humidity levels before being reintroduced into the rooms.
- Fresh Air Ventilation: While recirculating indoor air is the primary function of central air conditioning systems, they can also be equipped with fresh air ventilation capabilities. Fresh air ventilation involves bringing outside air into the system to dilute the indoor air and improve air quality.
Fresh air can be introduced into the system through dedicated ventilation ducts or through a ventilation system integrated with the air handler. The amount of fresh air brought in depends on factors such as local building codes, occupancy requirements, and the desired air exchange rate.
By incorporating fresh air ventilation, central air conditioning systems can help remove stale air, control odors, and maintain better indoor air quality. It can be particularly beneficial in buildings where there are concerns about indoor pollutants or in situations where occupants require access to a constant supply of fresh air.
It's important to note that the specific configuration of a central air conditioning system, including its capability for fresh air ventilation, can vary based on the design, installation, and specific requirements of the building or HVAC system in question. Consulting with a professional HVAC technician or engineer would provide the most accurate information regarding a specific system.