Interpretation #7103
Published October 24, 2012
Original Request
- Code Version
- 2010
- Code
- MECHANIC
- Code Description
- Mechanical
- Chapter
- 4
- Section
- 403.3
- Topic
- Approved Engineering Analysis
Question
Does the use of an "approved engineering analysis" allow the engineer to design a ventilation system with active contaminant control to use outdoor rates lower than the specified rates in Table 403.3 provided that calculations and/or can tests be provided to the AHJ to verify adequate IAQ conditions will be satisfied?
Answer Published 10/24/2012 at 10:34 AM
Yes. The more appropriate code section is, FMC 403.2,
Exception. Where the registered design professional
demonstrates that an engineered ventilation system design will
prevent the maximum concentration of contaminants from
exceeding that obtainable by the rate of outdoor air
ventilation determined in accordance with Section 403.3, the
minimum required rate of outdoor air shall be reduced in
accordance with such engineered system design.
Exception. Where the registered design professional
demonstrates that an engineered ventilation system design will
prevent the maximum concentration of contaminants from
exceeding that obtainable by the rate of outdoor air
ventilation determined in accordance with Section 403.3, the
minimum required rate of outdoor air shall be reduced in
accordance with such engineered system design.
Commentary
None.