Rating System

LEED BD+C: New Construction, LEED BD+C: Schools, LEED ID+C: Commercial Interiors, LEED BD+C: Core and Shell, LEED O+M: Existing Buildings

Rating System Version

v2 - LEED 2.2, v2 - Schools 2007, v2 - LEED 2.0, v2 - LEED 2.0, v3 - LEED 2008

Inquiry

The UCS suite is located on the 8th floor of a 12 story building in downtown Washington, DC. The building was built in the 1960\'s. This suite covers the entire floor of the building. The types of spaces in the suite consist of offices, open offices, conference room, meeting rooms, lunch room, pantry, lan room, storage and copy rooms. There are four meeting rooms and a conference room (room 876) in this suite. The meeting rooms are located along the perimeter of the suite and are being served by a separate exterior zone 100% outside air system. The conference room is located in the interior and is served by air-handlers in the penthouse which provide 25% outside air to the interior zones. These air-handlers serve other floors in the building also. This conference room is a critical space and currently does not meet the ASHRAE 62.1-2004 standard. The total outside air being provided to the suite is 6313 CFM. The total occupancy for the suite will be 85 people. Thus, we are supplying 74 CFM per person for the entire suite. For each space, the amount of outside air that we are providing is over 30% above the ASHRAE 62.1-2004 standard, except the conference room. Per ASHRAE 62.1-2004, we are 36% below the amount of ventilation air that is required for the conference room. This conference room is existing, with an area of 480 SF and occupancy of 24 people. 600 CFM of supply air was provided to this space under the existing design. Since the room did not change under the new design, the quantity of air was kept the same. The space will not be used for more than two to three hours at a time. Per local codes we are allowed to use a transfer fan and provide the extra air from adjacent office space to meet the ventilation requirements. We have the following questions: 1) Given the high amount of outside air for the rest of the suite, does USGBC accept the supply air quantity for the conference room for the minimum IAQ performance pre-requisite and increased ventilation credit? 2) If we need to increase the supply air quantity, how much do we need to increase it by, given that main air-handler provides 25% OA? 3) Does USGBC allow the use of a transfer fan to provide additional supply air to the space? 4) Are there other options that the owner can consider to achieve the increased ventilation credit?