Air Exchange Rate

{
  "id": "MLC-T-ENV-000845",
  "term": "Air Exchange Rate",
  "field": "Environment",
  "definition": "1. The rate at which outside air replaces indoor air in a given space.\n\n2. Rate of air leakage through windows, doorways, intakes and exhausts, and \"adventitious openings\" (i.e., cracks and seams) that combine to form the leakage configuration of the building envelope plus natural and mechanical ventilation.\n\n3. The rate at which outside air replaces indoor air in a space. Expressed in one of two ways: the number of changes of outside air per unit of time air changes per hour (ACH); or the rate at which a volume of outside air enters per unit of time - cubic feet per minute (cfm).\n\n4. Used in two ways: 1 ) the number of times that the outdoor air replaces the volume of air in a building per unit time, typically expressed as air changes per hour; 2) the number of times that the ventilation system replaces the air within a room or area within the building.",
  "subject": "Air",
  "references": [
    "Terms of Environment",
    "Exposure Factors Handbook: Glossary",
    "Indoor Air Quality Glossary",
    "I-BEAM Glossary of Terms"
  ],
  "url": "https://mlchart.com/terminology/environment/air-exchange-rate/"
}