Managing indoor air quality (IAQ) systematically during construction is becoming more and more common as contractors gain more experience with LEED. It benefits the health of everyone who works on the site, not just the eventual occupants of the building. 

Not a one-time thing

Earning this credit can be fairly easy, but it does require careful coordination and buy-in from all the subcontractors and field personnel involved in the project. It’s important to remember that IAQ management is not a one-time compliance event that can be checked off a list—it must be an ongoing effort for the duration of the construction process.

The contractor should create the IAQ management plan before construction even begins, and check on compliance at various times throughout the process—including collecting photos on a minimum of three separate dates for credit documentation.

SMACNA guidelines call for measures like wrapping ductwork to prevent dust from entering it during construction. (The commissioning process is supposed to catch poorly coordinated practices like the meeting of the sprinklers and ductwork here.) Photo – YRG Sustainability

Know the standard

LEED requires you follow the SMACNA 2007 guidelines. (See Resources.) Chapter 3 of the guide describes Indoor Air Quality (IAQ) management. The standard was updated in 2008, but is virtually identical to the older version referenced in earlier versions of the LEED rating system. Note that although the SMACNA guidelines say they are for "occupied buildings under construction," these guidelines must be used by all LEED projects attempting this credit—occupied or not.

The SMACNA 2007 document describes common sources for construction indoor air pollution and offers best practices to address them. When developing the IAQ Management Plan, the contractor should incorporate all of the recommended guidelines that are applicable to the project. 

The following are the major areas covered by SMACNA.

• HVAC Protection: Make sure that dust and construction debris do not accumulate in HVAC ducts. Strategies include wrapping HVAC ducts in plastic and storing ductwork in dust free areas before installing.
• Source Control: Address the sources of construction pollution and looking for ways to reduce them. Strategies include using low-VOC materials, paints, coatings, adhesives, sealants (as covered in IEQc4.1–4.4); exhausting gas-fueled construction equipment directly to the outside; and storing VOC-containing materials away from absorptive materials.
• Pathway Interruption: Use negative pressure and or temporary hanging plastic to contain areas that may generate construction dust, for example, wood-cutting and drywall-cutting areas.
• Housekeeping: Keep a clean work site by sweeping, wet mopping and using low-VOC cleaners.
• Scheduling: Coordinate the movement of occupants to minimize their exposure to construction debris; schedule installation of absorptive materials to limit the materials’ exposure to VOCs and moisture.

HVAC components that are poorly protected from dust and construction debris, as in this photo, can cause equipment malfunctions and poor IAQ during occupancy.

More than just SMACNA

In addition to the SMACNA requirements your project will be required to protect absorptive material from moisture through proper scheduling and storage. This includes drywall, carpet, ceiling tiles, and any other absorptive materials. Take pictures of this for documentation.

If HVAC equipment will be used during construction, you will need to install MERV 8 filters before operating them and replace them before the building is occupied.

Filter standards for international projects

International projects can follow international filter standards if using HVAC equipment during construction:

• Europe: Class F5 (defined by CEN Standard EN 779-2002)
• East Asia: Medium Efficiency or High Efficiency (defined by Chinese Standard GB/T 14295-2008)
• For all international projects: Minimum dust stop efficiency of 30% and arrestance of 90% for particles between 3–10 picograms

All other applicable SMACNA guidelines should be incorporated into the IAQ Management Plan.