Ashrae standard 62.2: What's new and why

ASHRAE Standard 62.2-2013, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings, incorporates 17 new addenda compared to the 2010 edition. About half of these are major changes to the requirements of the standard. Most of the changes were adopted to better ensure that the intent of the standard would be met in all residential buildings covered by this standard. These changes covered a range of issues, including the elimination of an assumed minimum amount of natural infiltration, how the effectiveness of intermittent ventilation is calculated, the basis on which alternate ventilation options shall be deemed equivalent to the prescriptive requirements, and a major new section on multifamily buildings. Other major changes included increasing flexibility of ventilation options through the removal of climate-specific restrictions and protecting residents from life-threatening carbon monoxide. This paper explores these changes with background on why they were adopted and implications for users.