Protocol for Conducting Measurements of ANSI/AARST MAH 2019 Radon and Radon Decay Products in Homes 25 EXHIBIT 4 SAMPLE DOOR HANGER NOTICE RADON TEST IN PROGRESS Required closed-building conditions (12 hours prior to the test and during the test) Keep closed Windows & Exterior doors (except for momentary use) Set to normal Heating & Cooling systems keep between about 65˚ - 80˚ F) Set to lowest outdoor ventilation Systems that temporarily ventilate with outdoor air for seasonal comfort or energy savings Avoid excessive operation Clothes dryers, range hoods and bathroom fans Do not operate Whole-house and window fans Fireplaces that burn solid, liquid or gas fuels, unless they are the primary sources of heat for the building Do not disturb test devices.