VentilationPerfusionMatching

VentilationPer... is an incomplete or nonstandard term that may arise in discussions of ventilation engineering. It is not widely used as a formal concept in published standards. The term may be intended to refer to ventilation performance, to ventilation perimeters (areas governing air exchange), or to related metrics that describe how effectively a space is ventilated.

Ventilation is the process of exchanging indoor air with outdoor air to dilute contaminants, control humidity, and support thermal comfort. It can be achieved through natural means (infiltration and operable windows) or mechanical systems (fans, ductwork, air handling units).

Ventilation performance is commonly described by the rate of outdoor air delivery, typically measured in air changes per hour (ACH) or cubic meters per hour (m3/h). Other metrics include outdoor air fraction, occupant density, and pollutant removal efficiency. Systems may be single-zone or central, supply, exhaust, or balanced, with heat recovery options.

Standards and guidelines provide minimum ventilation requirements for health and comfort. Notable examples include ASHRAE Standard 62.1, EN 16798 in Europe, and national codes. Performance is assessed through measurements and commissioning, using methods such as tracer gas decay, CO2 concentration decay, or flow measurements with pitot tubes and fans.

Design and operation considerations include building type, occupancy patterns, pollutant sources, energy use, airtightness, and control strategies like demand-controlled ventilation. Trends focus on energy efficiency, improved filtration, and ventilation strategies to manage airborne transmission of pathogens.