Exhaustonly

Exhaustonly is a term that describes a ventilation system designed to remove air from a space without introducing fresh outdoor air in a controlled manner. In such systems, fans are used to extract air, creating negative pressure within the building or room. This negative pressure can then draw air in through any available openings, such as cracks, gaps, or intentionally designed passive vents.

The primary purpose of exhaustonly ventilation is typically to control indoor air pollutants, moisture, or odors. For example, bathroom and kitchen exhaust fans are common examples of exhaustonly systems, designed to remove humidity and cooking fumes. In industrial settings, exhaustonly systems might be used to remove hazardous fumes or dust from a work area.

While effective for removing specific contaminants, exhaustonly systems can have drawbacks. They can lead to uncontrolled air infiltration, bringing in unconditioned outdoor air, which can impact energy efficiency and indoor comfort. In colder climates, this uncontrolled infiltration can also lead to condensation issues. Additionally, if not properly designed, exhaustonly systems can create excessive negative pressure, making it difficult to open doors and windows. More balanced ventilation systems, which introduce fresh air while exhausting stale air, are often preferred for overall indoor air quality and energy performance.