Which standard should projects in the U.S. follow when selecting filters with minimum efficiency reporting value (MERV)?

The correct approach for selecting filters based on minimum efficiency reporting value (MERV) is to refer to ASHRAE Standard 52.2-2007. This standard provides the testing methods and evaluation criteria for air filters, specifically in terms of their efficiency in removing particulate matter from the air, which directly influences indoor air quality. The standard categorizes filters based on their performance, enabling project teams to choose effective filters that enhance the building's ventilation system and overall air quality.

The use of MERV ratings is crucial because higher MERV ratings indicate a greater ability of the filter to capture smaller particles, hence improving the indoor environment for occupants. Adhering to ASHRAE Standard 52.2-2007 ensures that the chosen filters comply with recognized performance metrics in the industry.

Other options listed do not serve the specific purpose of guiding the selection of filters based on MERV ratings. The EPA Standard 26.4-2010 is not focused on filter performance; ISO 14001 is an environmental management standard that addresses overall environmental practices, rather than specific filtration efficiency; and while LEED v4.1 guidelines provide a framework for sustainable building practices, they do not specifically detail the MERV selection process, making ASHRA