MALB_2014 with 1-21 Revisions

Normative Appendix A ANSI/AARST MALB-2014 with 1/21 Revisions A— Reporting Building Operating Conditions 3 A-2.2 Test period calculations The duration of outdoor temperatures that dictate the building operating condition shall be based on local weather data using methods a) or b) of this Section A 2.2 : a) It shall be acceptable to total the hours of each building operation condition, based on hourly data published by local weather services, and report the percentage of time during the test that each operating condition occurred, as defined in Section A 2.1 ; or b) It shall be acceptable to use average outdoor temperatures that occur during the test, or time period of interest, for estimating the percentage of building operations across time. When using this method, the percentage of each operating condition shall be based on the percentage of outdoor temperature values, as defined in Section A 2.1 , that fall between the high and low outdoor temperatures during the test or time period of interest. Note— Table A-0 provides a quick reference for expected building operating conditions relative to average outdoor temperatures during a test. A-2.3 Variable outdoor air ventilation Because the duration and volume of outside air is dynamically variable for energy recovery ventilation and economizer systems , additional testing that meets requirements in a) or b) of this Section A 2.3 are required before any valid assumptions can be made. In absence of these procedures, no assumptions shall be reported regarding the effects of varying the volume of outdoor air ventilation. a) Simulation of conditions requires both: 1. A calculation that plots incremental changes of outdoor temperatures across a 365 day period and the corresponding volumes of modulated outdoor air introduced into the building at any given time, and 2. Radon testing to confirm the degree of outdoor air required for maintaining concentrations to below the action level . b) For radon testing of dwellings, or other 24 hour occupancies, the test duration shall be nominally 365 days or 180 days. The 180 day option shall include half of the heating season, half of the cooling season and the duration in between. Note—These testing options account for widely varying degrees of outdoor air introduced into the building where the outdoor air volume is modulated in response to incremental changes in outdoor temperature.