Factory Area Classification

I hope that this answers Question 1:

In Table 6-1 of ASHRAE-62.1-2007, General Note 6 states, “If the occupancy category for a proposed space or zone is not listed, the requirements for the listed occupancy category that is most similar in terms of occupant density, activities and building construction shall be used.” Additionally, Note 4 says only to us the default occupant densities from Table 6-1 “when actual occupant density is not known.”

Therefore, to determine the number of occupants, use the actual number of workers anticipated in each work area based on the actual number of workstations. If some or all of the occupants do not have fixed workstations, include the maximum number of other persons expected to be moving about in the work areas during peak periods.

Next, identify which of the Occupancy Categories from Table 6-1 have Default Occupant Density Values closest to your work areas. Then, identify which of these Categories most closely matches the activities that occur in your work areas. Remember that high levels of physical activity usually require higher ventilation rates, as do activities that involve contaminants such as dust and fumes.

Finally, you may need to backup your assumptions by researching relevant standards of industrial safety and workplace hygiene, as recommended by ASHRAE-62.1 Section 2.3 and in the Chapter 3 definition of “industrial space.”

Whatever approach you use, include your justifications in your documentation for IEQp1 & IEQc2. Since IEQp1 is a prerequisite, it might be wise to submit an inquiry and request an interpretation to validate your approach.

To answer Questions 2, 3, & 4, see the IAQ space matrix. (For the latest version, see http://www.usgbc.org/resources/eq-space-type-matrix.)