ASHRAE 62.1
Construction & System Start-Up

Section 7 addresses the construction and start-up phases of a project and has been included because a significant number of documented IAQ cases are a result of activities that took place during these project phases.

Mechanical barriers are specified to protect occupied areas from construction-generated contaminants. In addition, the HVAC system must be able to maintain occupied spaces at positive pressures with respect to the construction areas. In many cases, the HVAC system does not have adequate capacity and/or controls to provide a barrier to the migration of contaminants using positive pressurization flow. Designers must consider the condition of the existing ventilation system and its ability to maintain a pressurized environment for spaces expected to continue occupancy, prior to initiating physical construction activities at the site.

§7.2.2, Air Balancing, requires that systems be balanced,“...at least to the extent necessary to verify conformance with the total outdoor air flow and space supply air flow requirements of this standard.” Unfortunately, the airflow rates of the system will vary after this activity has occurred, in most systems, for reasons discussed in the analysis of Section 5, Systems and Equipment. When applied in accordance with the manufacturer’s recommendations, some airflow measuring devices only require the verification of operation by Test and Balance professionals. This TAB “snap-shot” of airflow rates is analogous to providing a one-time setup for temperature control, which obviously would not be very effective. Providing permanently mounted airflow measuring stations would also support compliance with and reduce the time required to supply the ventilation documentary requirements set forth in §7.2.6 (c).

Use EBTRON 's EB-Link option to instantaneously download traverse data independently of your building automation system for quick and reliable air balancing!