Good afternoon,
I have a question about the occupancy I have to take into account for the minimum air flow calculations. For the first review we entered the occupancy defined by the ASHRAE but the response was the following: "3.It appears that the values of occupancy used to define minimum outside air flow requirements via the supporting calculations are the design
occupancies listed in Table 6-1 of ASHRAE 62.1-2007. As indicated on the form, all values of occupancy used to define minimum outside air flow
requirements must be based on the maximum occupancy expected during normal facility operation and not design occupancy, minimum occupancy, or unusual or emergency conditions. According to the Reduced Occupancy Guidance for LEED for Existing Buildings Operations and Maintenance, 2009, the default values for occupancy listed in ASHRAE standard 62.1-2007 should be used only for completely vacant spaces."
We understood that we could not use the occupancy listed in the ASHRAE because it is the minimum occupancy and we need the maximum one. So for the next review we took into account the occupancy defined by the CTE (Spanish building code) that defines the maximum occupancy allowed in each space for some spaces and for the rest the occupancy defined by the owner. And now the response is the following: " ASHRAE Standard 62.1-2007 must be the criteria used instead of the CTE technical code."
What do we have to do? I am very confused. Please help me and thank you very much.
Ante Vulin
Sustainability ManagerYR&G
80 thumbs up
May 8, 2013 - 2:21 pm
Patricia, the main issue is determining how many occupants your space actually has during normal operation. LEED only wants you to use default numbers (from 62.1) for spaces that are vacant (i.e. have no tenants or occupants at all).
For the spaces in your project you want to estimate the actual occupants of a space, and enter that whole number into your calculations. Only by using the real occupancy can you correctly determine the actual critical zone. The real occupants can be determined based on chair count or tenant-self-reporting, but cannot be based on code default assumptions. In my experience the LEED reviewers will trust the number of occupants that you provide.