As Commissioning providers, we typically spot–check diffuser airflow rates in rooms to verify the testing & balancing (TAB) report. In one case, we discovered that the design airflows were not being achieved even though the TAB report showed compliance. Upon comparison with the TAB contractor’s airflow measuring device, we discovered that their device was not calibrated. They then recalibrated, remeasured, rebalanced, and ensured proper airflow rates and indoor air quality.
On another project, the client asked us to test the supply and return air systems before the final building handover. Due to the construction of the supply air diffusers, it was not possible to measure the volume flow directly. We decided to use a fog machine to verify the airflow in the rooms. This approach identified five office spaces that received low or nearly no air volume flow. From our Commissioning Report, the on-site engineer was able to quickly adjust the required airflows.
It is valuable when a Commissioning provider can verify test results with their own measurement devices. However, in situations where this is not possible, we need to be creative and come up with other solutions.