ASHRAE Standard Revised to Cut Excess Ventilation

ASHRAE’s 62.1-2013 standard gives project teams more flexibility to determine appropriate exhaust rates, providing potential energy savings.

The 2013 version of ASHRAE’s indoor air quality standard has been published with 10 addenda to the 2010 standard. According to Roger Hedrick, Standard 62.1 committee chair, the updates will allow building designers and operators to reduce energy consumption by cutting “excess ventilation.”

Some changes could help projects avoid unneeded prescriptive measures; for example, a performance-based option for exhaust rates is added. Notably, this addendum requires monitoring concentrations of contaminants, unlike the existing performance-based method for setting supply ventilation rates. Ventilation rates for sports spaces (such as spottily occupied school gymnasiums) can also be determined partly on a per-occupant basis, allowing ventilation levels to be adjusted based on demand. Toilet exhaust air may now be recirculated after appropriate treatment.

There are also modified requirements for water used in humidification systems and zone air distribution effectiveness for underfloor air distribution. Air entering wetted cooling coils must be filtered to MERV 8—a more stringent requirement than the previous MERV 6 level—in order to reduce potential for particulate deposit on the coils.

Standard 62.1-2013 can be purchased from ASHRAE’s online bookstore.