Rating System

LEED BD+C: New Construction

Rating System Version

v2 - LEED 2.2

Inquiry

This CIR is a follow up to the ruling received from the USGBC on 10/8/08 regarding the earlier CIR that was submitted by the project team on 9/12/2008 on this subject. The building in question is a freezer warehouse, consisting of an unoccupied freezer, a normally occupied office/support area, and an intermittently occupied loading dock. The previous ruling established that the office area must comply with ASHRAE 62.1, and that the unoccupied freezer is exempt from compliance. The ruling did not explicitly address the status of the loading dock. The project team is requesting a ruling that confirms that the following approach will comply with the intent of the prerequisite for the loading dock. In summary, it is not standard practice to mechanically ventilate a refrigerated loading dock, the dock is large relative to the number of occupants, and the combination of operable doors, CO2 sensors, and intermittent occupancy mean that IAQ will be maintained within acceptable limits without providing mechanical ventilation. Standard Design Practice It is neither the owner\'s standard practice, nor that of the industry in general, to provide mechanical ventilation to refrigerated spaces such as the loading dock. Providing additional mechanical ventilation creates the following problems:  Potential problems with condensation and high humidity  Potential worker safety issues if condensation causes wet floors or fog  Potential product spoilage/safety issues related to high humidity and moisture, as well as any contaminants that might be introduced from outside air  Additional refrigeration load Based on these concerns, the project team\'s strong preference is not to mechanically ventilate the loading dock in order to meet this prerequisite. Proposed Compliance Approach In order to meet the intent of EQ Prerequisite 1, the following approach is proposed.  The dock is large (25,832 sf / 802,002 cf) relative to the number of occupants (10), or 2,583 sf / 80,200c.f. per person. Through normal dilution, it is likely that the levels of contaminants that might be created in the dock area will remain at an acceptably low level.  The dock has 18 loading dock doors. The total area of the dock doors exceeds 4% of the floor area of the space. Although there is a dock seal when a truck is parked at the dock, the doors are often left open between trucks. Additional, unoccupied doors could also be opened if needed. Per the LEED Handbook the manual operable doors seems to satisfy the natural ventilation procedure.  The customer will install CO2 sensors in the loading dock area with a visible alarm if levels exceed a predetermined threshold. The alarm would be an indication that workers could open dock doors if needed.  The dock will only be occupied intermittently by the workers. The workers will also go into the logistics office which will have mechanical ventilation in compliance with ASHRAE 62.1