Interpretation #7252

Original Request

Code Version: 2010
Code: MECHANIC
Code Description: Mechanical
Chapter: 4
Section: 401.4.1
Topic: Separation of air intake and exhaust

Question

Is it the intent of section 401.4.1 to permit the

mechanical air intake for a dwelling unit to be

within 10 feet of a residential bathroom, kitchen

or dryer exhaust? Specifically, can the intake be

located no less than 36 inches away from these

exhaust outlets?

Answer Published 11/13/2013 at 7:47 PM

NO. This code section does not contemplate "environmental

air". FMC 401.4 provides a similar option of an intake
opening not less than 3 feet below contaminant sources,
however the application must also comply with 4 other
requirements.

Commentary

401.4 item #2 references compliance with 501.2.1. 501.2.1 item #3 deals specifically with the termination of environmental air (which includes domestic dryers, bathroom exhaust and domestic kitchen exhaust). There is actually a conflict within the code stipulating the 10 foot separation in 501.2.1 item #3 and 401.4.1 indicating that bathroom or kitchen exhaust from a residential dwelling not be considered a hazardous or noxious contaminant and therefore potentially exempt from the 10 foot rule of 401.4.1. The more stringent rule should apply. Thus,the environmental air exhaust must terminate a minimum of 10 feet from any mechanical ventilation intake location.