What type of ventilation uses localized fans to quickly remove pollutants at their source?

The correct answer is exhaust ventilation, which is specifically designed to address indoor air quality by swiftly removing pollutants directly from their source. This type of ventilation employs localized fans to extract stale air, odors, and contaminants, thus directly improving the air quality in a space. By targeting the source of the pollutants, exhaust ventilation effectively reduces the concentration of harmful substances, which is particularly important in areas where emissions from processes, cooking, or other activities generate immediate hazards or discomfort.

Supply ventilation introduces fresh air into a space but does not remove existing pollutants, whereas balanced ventilation systems bring in equal amounts of fresh air and exhaust stale air, which can be effective but slower in addressing high-pollutant scenarios. Passive ventilation relies on natural flow and does not use mechanical means, making it less effective for quick removal of localized pollutants. These alternatives highlight why exhaust ventilation is the optimal choice for rapidly clearing contaminants from a specific area.