Equivalence in ventilation and indoor air quality

Abstract

This study ventilates buildings to provide acceptable indoor air quality. Ventilation standards (such as ASHRAE Standard 62) specify minimum ventilation rates without taking into account the impact of those rates on indoor air quality. Innovative ventilation management is often a desirable element of reducing energy consumption or improving indoor air quality or comfort. Variable ventilation is one innovative strategy. To use variable ventilation in a way that meets standards, it is necessary to have a method for determining equivalence in terms of either ventilation or indoor air quality. This study develops methods to calculate either equivalent ventilation or equivalent indoor air quality, demonstrating that equivalent ventilation can be used as the basis for dynamic ventilation control, reducing peak load, and infiltration of outdoor contaminants. It is also shown that equivalent indoor air quality could allow some contaminants to exceed current standards if other contaminants are more stringently controlled.

Acknowledgments

This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of the Building Technologies Program, U.S. Department of Energy (contract DE-AC02-05CH11231).

This article not subject to U.S. copyright law.

Max H. Sherman, PhD, Fellow ASHRAE, is Senior Scientist. Iain S Walker, PhD, Fellow ASHRAE, is Staff Scientist. Jennifer M. Logue, PhD, is Post-Doctoral Fellow.

Notes

Danish Building Regulation BR10 (2010), http://www.ebst.dk/bygningsreglementet.dk; HealthVent (2011), Health-Based Ventilation Guidelines for Europe 2011, http://www.healthvent.byg.dtu.dk/, http://www.healthvent.byg.dtu.dk/; CEN (2001), EN1752: Ventilation for Buildings—Design criteria for the indoor environment 2001.

The criterion is somewhat different for exposure to particulates, but, as shown in the Discussion section, that issue is moot.

Adaptation refers to the decreasing sensitivity to bioeffluent odors with time. Sensitivity to the odors of humans around decreases in a few minutes compared to a first impression that visitors might have. The adapted level is appropriate when considering a minimum standard, such as 62.2.