Closed apartments can still have some level of ventilation even when the air conditioning (AC) is turned off. Here are a few factors that contribute to ventilation in closed apartments:
Natural ventilation: If the apartment has windows, opening them allows fresh air from outside to circulate inside the apartment. Natural ventilation relies on wind movement and temperature differences to create airflow. Opening windows on opposite sides of the apartment can facilitate cross-ventilation, where fresh air enters from one side while stale air exits from the other.
Passive ventilation: Some apartments may have passive ventilation systems designed to allow airflow without relying on mechanical systems. These systems utilize architectural features like vents, ducts, or chimney stacks to create a natural stack effect. As warm air rises, it creates a pressure difference that draws fresh air in from lower levels or external sources.
Building ventilation systems: Many modern buildings are equipped with mechanical ventilation systems that are designed to operate independently of the AC. These systems use fans to draw in fresh air from outside and distribute it throughout the building, promoting air exchange. The ventilation system may have a separate control or operate on a timer even when the AC is turned off.
HVAC system design: In some cases, the apartment's heating, ventilation, and air conditioning (HVAC) system may be designed to provide a minimum level of ventilation even when the AC is not running. This could involve a dedicated ventilation fan that operates independently or a system that uses a portion of the AC's airflow to provide continuous ventilation.
It's worth noting that ventilation in closed apartments may not be as effective as in open spaces or those with active mechanical ventilation. The natural or passive ventilation methods mentioned above may be limited by external factors such as weather conditions or the surrounding environment. Additionally, ventilation is essential for maintaining indoor air quality, so it's generally advisable to periodically open windows or use mechanical ventilation systems to promote fresh air circulation, especially when the AC is off for extended periods.