If a room is humid with low natural ventilation, what is the most cost-effective solution?

In a scenario where a room is humid and has low natural ventilation, the most cost-effective solution is to use an exhaust fan. An exhaust fan works by removing humid air from the room and simultaneously allowing fresh air to enter from other areas, thereby improving air circulation and reducing humidity levels. This system is particularly effective in spaces with poor ventilation because it actively expels moisture-laden air, thereby lowering humidity without needing extensive modifications or additional mechanical systems.

An exhaust fan is more energy-efficient than alternatives that may not target moisture directly. For example, a humidifier would add moisture to the air, which is counterproductive in already humid conditions. A ceiling fan may help in circulating air but does not effectively reduce humidity levels; it simply redistributes the air within the room. Similarly, a ventilator, which often includes additional features for heat recovery or air conditioning, can incur higher costs and complexity than necessary when a simple exhaust fan can achieve the desired outcome of reducing humidity efficiently and cost-effectively.