Page 299 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

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daily start time and operated at the minimum outside air flow rate for the occupied
mode throughout the duration of the air testing.
2) The building shall have all interior finishes installed, including but not limited to
millwork, doors, paint, carpet and acoustic tiles. Non-fixed furnishings such as
workstations and partitions are encouraged, but not required, to be in place for the
testing.
3) The number of sampling locations will vary depending upon the size of the building
and number of ventilation systems. For each portion of the building served by a
separate ventilation system, the number of sampling points shall not be less than
one per 25,000 sq. ft., or for each contiguous floor area, whichever is larger, and
include areas with the least ventilation and greatest presumed source strength.
4) Air samples shall be collected between 3 feet and 6 feet from the floor to represent
the breathing zone of occupants, and over a minimum 4-hour period.

Potential Technologies and Strategies
Prior to occupancy, perform a building flush-out or test the air contaminant levels in the
building. The flush-out is often used where occupancy is not required immediately upon
substantial completion of construction. IAQ testing can minimize schedule impacts but
may be more costly. Coordinate with Indoor Environmental Quality Credits 3.1 and 5 to
determine the appropriate specifications and schedules for filtration media.

Calculations and Considerations (LEED 2009)
The intention of this credit is to ensure that a building has good air quality after
construction. The end of construction is defined as the completion of the stage when all
finishes are applied to the base building components and as noted in LEED 2009, after
all punch-list items are complete. Furniture and furnishings are not a part of the base
building. Also, this credit does not apply to the core and shell portion of LEED until the
interior finishes are complete.
There are two main methods of compliance: either there is a substantial flush-out of
the building and HVAC systems in either of two prescribed manners, or the team proves
that several marker air pollutants are below a certain minimum level after some flush-
out. Since it may be costly or unrealistic to delay occupancy after construction is
complete for many projects, the second flush-out option allows for the building to be
occupied earlier. Also, if there are separate HVAC systems in distinct areas of the
building, areas which are completed can be occupied prior to completion of all the
areas, if the compliant areas are also isolated and protected by the SMACNA principles
as outlined in IEQc3.1. In LEED 2009, it is required that the filter media are replaced
prior to flush-out, the filters should be replaced following any flush-out and the filter
media should meet the minimum requirements of the design or MERV 13 if IEQc5 is
also being sought. There are standards set for the temperature and relative humidity
(RH) of the outside air used for flush-out to prevent excessive moisture in the building
and also to promote evaporation of the applicable volatile compounds. Volatility
increases rapidly with temperature for many organic compounds that are intended to
be flushed out of the building. Therefore, to facilitate a rapid flush-out, the temperature
of the air used in the flush-out should not be too low.
Prescribed Flush-Out Options The first flush-out option requires a substantial amount of
air and may take a few weeks. The second flush-out option requires that a portion (at least
25 percent) of the flush-out be completed prior to occupancy and then can continue at a
minimum rate during occupancy until complete.