RMS-LB 2018 with 12/20 Revisions

Identify—The Normal Average Operating Condition for the Building CG AARST Companion Guidance RMS-LB 2018 Informational 8 Note: The following methodology is intended to be simplistic yet reasonable for use. Other methodologies can include identifying exact control settings for each system or more precise calculations for outdoor temperatures (i.e. extrapolations in terms of degree day calculations). Such methods might provide precision evaluations yet can be overly exhaustive in terms of the needs and purpose. Steps to identify the normal average operating condition for the building for initial or follow-up radon tests; diagnostic tests; and post-mitigation tests. 1) Know The Average Occupied Indoor Temperature: 74˚ F (23˚ C). Due to required comfort for occupants, the average indoor temperature is usually maintained with stability between 68˚ to 82˚ F (20˚ to 28˚ C). Use an average of about 74˚ F (23˚ C) during estimations unless known to be specifically different. HVAC systems are set to respond to needs for maintaining this comfort range during significantly occupied periods. 2) Identify The Average Local Outdoor Temperatures During Significantly Occupied Months. HVAC systems respond to changes in outdoor temperatures by activating heating, cooling and ventilation air handlers including certain designs that introduce outdoor air ventilation into a building. 3) Identify Periods When Heating and Cooling Systems Activate. Heating Systems: In response to needs for indoor comfort: Heating systems will often activate when outdoor temperatures drop to below about 65° F (18˚ C). Cooling Systems: In response to needs for indoor comfort: Cooling systems will normally be active when outdoor temperatures exceed about 75° F (28˚ C). Examples of Heating and Cooling Activity 24 Hour Averages Daytime Only Averages