The assessment must be detailed enough for management to gain a comprehensive understanding of all of the factors that could influence the building’s indoor air quality. It must consist of a walkthrough inspection of the building and must report on a review of the following: a list of responsible staff and/or contractors, evidence of training, and job Descriptions, HVAC design data, manuals and operating instructions including control settings and operating schedules, HVAC maintenance and calibration records, testing and balancing reports, inventory of locations where occupancy, equipment, or building use has changed, identification of areas where positive or negative pressures should be maintained, a record of locations that need monitoring or correction, and an inventory of HVAC system components needing repair, adjustment, or replacement.

Suggested performance goals for IAQ include the following for frequently occupied indoor spaces:

• Carbon dioxide not exceeding 700 ppm above ambient (ASHRAE 62.1);
• Carbon monoxide not exceeding 9 ppm (ASHRAE 62.1);
• Total volatile organic compound concentrations do not exceed 1000 μg/m3 (440 ppb) (Health Canada);
• PM10 does not exceed 50 μg/m3 (ASHRAE 62.1);
• Temperature in the range of 21 – 27 C°, taking into account seasonal variances, relative humidity (ASHRAE 55);
• Relative humidity in the range of 30-60% (USEPA I-BEAM) or more than 20% (CSA);
• HVAC system interiors are in good general condition, clean, free of standing water and debris, and have no visible suspect mould growth.
• If other local regulations exist for the above performance criteria, the most stringent will apply.

Regarding the preventative maintenance schedule for HVAC that will impact IAQ, include language regarding how environmental quality performance will be verified. At a minimum, testing should be conducted over a typical workday, taking into account fluctuations in contaminant levels that may occur. Testing should be conducted, at a minimum, in the morning and afternoon.

During flu season and/or pandemic response consider the following ASHRAE HVAC operation recommendations:

• Maintain temperature and humidity design set points;
• Maintain equivalent clean air supply required for design occupancy whenever anyone is present in the space served by a system
• When necessary to flush spaces between occupied periods, operate systems for a time required to achieve three air changes of equivalent clean air supply
• Limit re-entry of contaminated air from energy recovery devices, outdoor air and other sources to acceptable levels