International Mechanical Code
IMC 2009

It is significant to recognize the magnitude of influence that the IMC carries. At last count, the IMC2009 is being used in a total of 47 states and territories which have or soon will require compliance to the IMC. About 95-98% of the U.S. population will be subject to the ICC's Mechanical Code.

SECTION 403 - MECHANICAL VENTILATION. When mechanical ventilation is used, specific minimum rates of ventilation must be supplied, based on occupancy, floor area and structure. These rates are listed and defined in Table 403.3, and are now consistent with the Ventilation Rate Procedure in ASHRAE Standard 62.1-2010.

The most significant difference between this and previous versions is the same as the difference between ASHRAE Standard 62.1-2001 and 2004. The ventilation rate calculation requires the combined requirements of ventilation per person (as before), PLUS ventilation required per floor area. When distilled, this chapter of the IMC requires that the minimum rates specified in the tables must be provided "continuously" during occupation and controlled "...to automatically maintain the required outdoor air supply rate...over the entire range of supply air operating rates."

The simple and most efficient way to ensure that specific rates of outdoor air are introduced to the air handling system is to simply measure the outdoor air flow directly. EBTRON airflow measuring devices installed in the outside air intake can ensure compliance with the IMC2009 during startup and operation.

For more information, contact EBTRON or your local EBTRON representative.