The ventilation equipment itself generally does not increase the indoor humidity. If the ventilation equipment has no humidification function, the humidity of outdoor air may be different during the introduction of outdoor air, which may have a certain impact on the indoor humidity. In the dry season, the outdoor air is dry, and ventilation may make the indoor humidity drop slightly; In humid seasons, the outdoor air is humid, and ventilation may increase the indoor humidity. However, the impact is usually small, mainly depending on indoor water sources, personnel activities, climate conditions and other factors. For example, in winter in the north, the outdoor air is dry and cold. After ventilation with ventilation equipment, the indoor humidity may drop slightly, and humidifiers need to be properly used to increase humidity; In the plum rain season in the south, the outdoor air is humid, and the air introduced by the ventilation equipment may increase the indoor humidity, so it is necessary to turn on the dehumidification equipment to reduce the humidity.