ASHRAE RP-1581 was created to address an important issue currently faced by test facilities measuring static pressure for air-conditioning and heat pump equipment. Specifically, ASHRAE Standard 37 requires an outlet duct of a certain length, based on the unit outlet geometry, and this ducting added to the unit height may result in a test apparatus height that exceeds psychometric test room dimensions. An inlet duct is recommended as well, yet most facilities use a damper box at the inlet in order to complete cyclic testing as required for the SEER rating.