MALB_2014 with 1-21 Revisions

Conducting Measurements of Radon and Radon ANSI/AARST MALB-2014 with 1/21 Revisions Decay Products in Schools and Large Buildings 39 9.65 Time-Sensitive Situations where mitigation decisions are needed relatively quickly, such as within several days or weeks. Time sensitive measurement strategies entail a single phase of testing with enhanced quality control measures. 9.66 Unique Sector Portions of a common building that are classified by the general design and intended purpose of each active heating, cooling and ventilation system ( HVAC ). 9.67 Valid Sample Time The period representing occupied conditions after stabilizing building conditions with initiation of the closed-building protocol. Examples of valid sampling times include: The period beginning 12 hours after closed-building protocols are initiated or 24 hours after activation of a radon mitigation system . Valid sampling time is further defined by all other related requirements within this standard. 9.68 Variable Air HVAC designs where airflow from a single air handle is distributed among multiple Volume Systems (VAV) dwellings or rooms that temper room temperatures using thermostats to vary the volume of heated or cooled air delivered into rooms. See Exhibit 6, Group 4 Systems. 9.69 Variable Outdoor Systems that seasonally vary outdoor air ventilation for seasonal comfort or energy Air Ventilation savings. See Exhibit 6, Group 3 Systems. 9.70 Working Level (WL) A unit of radon decay product concentration. One WL equals any combination of short-lived radon decay products in 1 liter of air that will result in the ultimate emission of 1.3 x 10 5 MeV of potential-alpha energy. It is approximately the alpha- particle energy released from the decay products in equilibriumwith 100 pCi of Rn- 222.