RMS-LB 2018 with 12/20 Revisions

Identify—The Normal Average Operating Condition for the Building CG AARST Companion Guidance RMS-LB 2018 Informational 10 A. Identify The Normal Occupied Operating Condition: For the purposes of this document, the “Normal Occupied Operating Condition” is defined as: The operational condition for the building or unique sector of the building that represents the greatest amount of significantly occupancy time. B. Identify the operating conditions most likely to emphasize a clear characterization of a radon hazard. This would primarily include time periods when the difference between indoor and outdoor temperatures cause: a) Some degree of regularity for natural negative air pressure inside the building as compared to outside of the building (e.g. stack effect), and; b) Some degree of regularity in the activity of heating or cooling system blowers. This blower activity can cause negative pressure within the building, unique sector of the building or even an individual room. This would not include time periods when the volume of outdoor air introduced into the building exceeds the minimum amounts required to maintain occupant health. Examples Daytime Averages Daytime with Outdoor Air Systems