Why does using a fan cause nasal congestion while using an air conditioner does not, and what should I do about it?

Fan use may cause nasal congestion, while air conditioning usually does not, which is typically related to the different working principles of the two. The specific analysis is as follows:

A fan draws in surrounding air and blows it directly onto the body, potentially carrying dust, pollen, and other particles. These airborne particles may irritate the nose and throat, leading to nasal congestion. Additionally, if the airflow from the fan is too strong, it may dry out the mouth and throat, causing discomfort. In contrast, an air conditioner draws indoor air through a filter that removes dust, pollen, and other particles, thereby purifying the air. Air conditioners also regulate indoor temperature and humidity, contributing to greater comfort. Therefore, using an air conditioner is less likely to contribute to nasal congestion.

However, if the air conditioner's filter is not cleaned or replaced regularly, it can accumulate dust and other particles, which may then be released into the air and irritate the nose and throat, potentially causing nasal congestion. Thus, regular cleaning and replacement of air conditioner filters is essential for maintaining good indoor air quality and reducing the risk of nasal congestion.