The project is a 15,000sf fire station in Texas.To protect the building\'s HVAC system, we will be flushing out the building using a temporary heating unit using 100% outside air. We will use the equivalent performance methodology of providing 14,000ft3/ft2 and ending the flush out on the 14th day after construction, while maintaing 60 degrees. This unit will not be tied to the building\'s ductwork.The construction schedule for the project requires that the building be occupied in stages.We are proposing the following plan1. Flush out the first half of the living quarters portion by dividing the building with doors and by providing a temporary air-tight enclosure in a corridor. All vents and return air grilles will be sealed to avoid any cross contamination.2. Flush out the second half of the living quarters portion by the process outlined above.3. We are not planning to flush out the apparatus bay and the supporting rooms. These rooms do not have doors and open directly onto the bay. The bay does have unit heaters mounted high above the floor that serve to protect the equipment from extreme cold and to prevent the piping from freezing. The supporting rooms do not have any heaters or HVAC equipment. Our understanding is that flush out would not be necessary because of the nature of these spaces and because they are not served by a HVAC system. It would not be possible to flush them out using the standard LEED methodology of using the installed HVAC systems. Further, the bay usually has at least one 14x14 door open when the fire suppression personal are in there.Our request for interpretation is if this plan is acceptable.
This CIR appears to be in two parts. 1) Can the project, using the equivalent performance methodology, be flushed out in phases? 2) Can the apparatus bay and supporting rooms be excluded from the requirement for flush out?In response to the first part, previously posted NC v2.0/2.1 CIR rulings, dated 10/17/2001, 9/5/2006 and 10/23/06, approve the process for a staggered flush-out approach, provided that existing spaces are protected from construction-related contamination as well as prevention of cross-contamination between systems. Protection measures should follow the SMACNA Guidelines for Occupied Buildings and be outlined in the Construction IAQ Management Plan to ensure compliance.Also, the use of temporary ventilation units to accomplish the flush-out using the 14,000 ft3 / ft2 alternate approach described in the NC v2.0/2.1, 10/4/2004 credit ruling is acceptable, assuming the temporary units are capable of meeting the temperature and humidity targets.In response to the second part, the apparatus bay and supporting rooms are considered part of the entire submitted project and therefore must be considered part of the square footage calculated for this credit.The intent of this credit is to eliminate indoor air quality problems that occur as a result of construction. The use of outside air for flushout of the building is intended to reduce contaminants that are the result of the construction process.In order to achieve EQ credit 3.2, all "Occupied spaces" as defined in ASHRAE 62.1-2004 must either:(1) demonstrate that natural flush-out through the use of the 14X14 operable door, and/or temporary HVAC units, provides an equivalent of supplying a total air volume of 14,000 ft3 of outdoor air per ft2 of floor area while maintaining an internal temperature of at least 60