This CIR is to a request for clarification for the 9/8/04 CIR Ruling regarding equivalent performance methodology for flush out. First we want to confirm that if the specified volume of air is provided in less than a 2-week period that this is acceptable. Second, we want to confirm that it is acceptable to complete the volumetric flush out without operating the permanent units. In an effort to protect the permanent HVAC system and provide superior indoor air quality, we are proposing to conduct the flush out using a temporary 100% outside air HVAC unit (with MERV 13 filters), which will also maintain the space temperature and humidity within the specified ranges in the 9/8/2004 Ruling. The permanent units will not be operated and the duct openings will be sealed until after the flush out period has been completed using the temporary HVAC units. (Note: For our project a 3,000 cfm temporary unit will supply the required total air volume in five days.) Additionally, we understand from the 11/29/04 Ruling that the flush out period must be scheduled to allow installed materials to off gas for two weeks after the installation of emitting materials. Therefore, under the proposed strategy, the last of the emitting materials will be installed 9 days prior to the start of the flush out period. Before we proceeded under these assumptions, we wanted to receive feedback on the likely outcome of this overall strategy. Note: If two-week off-gassing period is required as stated in the 11/29/04 Ruling, this information needs to be captured in the revisions proposed for v2.2.
The use of temporary ventilation units to accomplish the flush-out using the 14,000 ft3 / ft2 alternate approach described in the 9/8/2004 credit ruling is acceptable, assuming the temporary units are capable of meeting the temperature and humidity targets. Per the 11/29/2004 Ruling, projects using this alternate path must schedule the flush-out such that it concludes at or later than two weeks after construction ends in order to expel the majority of product off-gassing. Applicable internationally.