ME27272727
Mechanical
- May 15, 2014
- 88
Can someone help me out with the difference between "outdoor air" and "ventilation air" as defined in the international mechanical code?
From chapter 2 definition of 2015 IMC:
Outdoor Air - Air taken from outdoors, and therefore not previously circulated through the system.
Ventilation Air - That portion of supply air that comes from outside (outdoors), plus any recirculated air that has been treated to maintain the desired quality of air in a designated space.
Why it matters... From the 2015 International Existing Building Code:
809.2 Altered Existing Systems - In mechanically ventilated spaces, existing mechanical ventilation systems that are altered, reconfigured, or extended shall provide not less than 5 cubic feet (cfm) per person of outdoor air and not less than 15 cfm of ventilation air per person; or not less than the amount of ventilation air determined by the Indoor Air Quality Procedure of ASHRAE 62.
From chapter 2 definition of 2015 IMC:
Outdoor Air - Air taken from outdoors, and therefore not previously circulated through the system.
Ventilation Air - That portion of supply air that comes from outside (outdoors), plus any recirculated air that has been treated to maintain the desired quality of air in a designated space.
Why it matters... From the 2015 International Existing Building Code:
809.2 Altered Existing Systems - In mechanically ventilated spaces, existing mechanical ventilation systems that are altered, reconfigured, or extended shall provide not less than 5 cubic feet (cfm) per person of outdoor air and not less than 15 cfm of ventilation air per person; or not less than the amount of ventilation air determined by the Indoor Air Quality Procedure of ASHRAE 62.
