"Determine where in the building IAQ testing will be performed.
First, perform an initial analysis to identify potential locations to test in the building. Consider locations that are most representative of the building space, and where occupants will normally spend their time.
• Identify at least one location per ventilation system. Include locations that represent the worst-case zones where the highest concentrations of contaminants of concern are likely to occur.
• Identify at least one location per floor of the building.
• Identify at least one location per space type. In most cases, only regularly occupied spaces need to be included. Additionally, for each space type identified, if the air is not well mixed or contaminants are not expected to be uniform throughout the space include more than one location in the space for testing.
Next, determine whether a sampling protocol can be used to reduce the number of testing locations identified in the initial analysis. A sampling protocol is particularly useful if the project has many floors or a large number of ventilation systems.
• Identify and group spaces (or floors) that are very similar in their construction, finishes, configuration, size, and HVAC systems.
• Randomly select one out of every seven very similar spaces to include in the testing. In addition, for buildings with a large number of identical spaces (more than 21 spaces in a sample group), test a minimum of three spaces in the sample group."
Under Step 2. Perform Test, add the following to the first paragraph, after the second sentence:
"If a test fails and a sampling protocol was used, conduct re-testing to assess whether the failure is unique or the rest of the spaces are likely to have similar failings."