New requirements regarding natural ventilation, exhaust systems and the IAQ procedure are included in ANSI/ASHRAE’s 2010 version of Standard 62.1.

New requirements regarding natural ventilation, exhaust systems and the IAQ procedure are included in ANSI/ASHRAE’s 2010 version of Standard 62.1, Ventilation for Acceptable Indoor Air Quality. The standard sets minimum ventilation rates and other requirements for commercial and institutional buildings.

“Since first being published in 1973, the standard has provided the basis for ventilation system design throughout the industry,” says Committee Chair Roger Hedrick. “The 2010 standard furthers ASHRAE’s work in ensuring acceptable indoor air quality, while also heeding the need for energy efficiency as we strive to find ways to help designers tailor ventilation system designs to each particular application.”

Among the changes to the 2010 standard are modifications to the natural ventilation rate procedure, which now requires that most buildings designed to meet the natural ventilation requirements also include a mechanical ventilation system designed to meet the ventilation rate or IAQ procedures. The mechanical system is to be used when windows are closed due to extreme outdoor temperatures, noise and security concerns.

“Most buildings using natural ventilation in the United States are high-rise residential buildings that often have no form of outdoor air intake other than operable windows,” Hedrick says. “This results in buildings with inadequate ventilation, because occupants often leave the windows closed in order to run the air conditioning, keep out noise, etc. The committee felt it needed to strengthen the existing prescriptive requirements to ensure adequate ventilation and their corresponding IAQ benefits are available to occupants.”