The project involves the remodeling of a fieldhouse building in Toledo, OH, to incorporate classrooms, lecture halls and academic office spaces. The Mechanical Systems will be completely replaced to accommodate an entirely different space use. The Project Team would like to use the IAQ Procedure, as described in Section 6.3 ASHRAE Standard 62.1-2004 (the "Standard"), in place of the Ventilation Rate Procedure of the same Standard. Rather than determining the volume of outside air needed based on space type/application, occupancy level, and floor area, the building and ventilation systems are designed to maintain the concentrations of specific contaminants at or below certain limits identified during building design and to achieve the design target level of perceived indoor air quality acceptability by building occupants and/or visitors, excluding dissatisfaction related to thermal comfort, noise and vibration, lighting, and psychological stressors. The design will strive to provide satisfaction in those areas as well, but those areas will not be measured by this procedure. The Project Team will use the documentation guidelines prescribed in Section 6.3.2 of the Standard with all assumptions documented according to Sections 4.3, 5.2.3, 5.17.4 and 6.3.2. The Project Team will use mass balance analysis as their design approach, using a computer-generated model to simulate contaminant levels, ventilation rates and effectiveness of mechanical filtration systems. The goal of the Project Team, by using this procedure to guide their HVAC design, is to optimize energy performance without compromising indoor air quality.
The CIR is inquiring if the IAQ Procedure, as described in Section 6.3 ASHRAE Standard 62.1-2004, can be used in place of the Ventilation Rate Procedure of the same Standard to document compliance with the requirements of this prerequisite. The Ventilation Rate Procedure methodology found in Section 6.2 of ASHRAE 62.1-2004 is the required approach in EQp1, since it is prescriptive and therefore more straightforward to apply. The Ventilation Rate Procedure is based on contaminant sources and source strengths that are typical for common space types listed in the Standard. The Indoor Air Quality (IAQ) Procedure methodology found in Section 6.3 of ASHRAE 62.1-2004 and proposed by this project team is performance-based and relies on identification of contaminants of concern, sources for those contaminants, concentration targets, and perceived acceptability targets. The project-specific nature of the IAQ procedure methodology makes it less commonly used and more difficult for USGBC to evaluate. Therefore USGBC cannot allow its use to show compliance with LEED NC v2.2 EQp1. Please note that the intent behind this prerequisite is to encourage designers to take the most stringent and conservative prescriptive approach to providing fresh air. The language of the prerequisite asks designers to compare the rates recommended under Ventilation Rate Procedure with that required by their local code and to pick the most stringent. As for the project team\'s legitimate concern with energy efficiency, the "additive" Ventilation Rate Procedure adopted in the ASHRAE Standard 62.1-2004 reflects concerns for energy consumption with elevated ventilation rates. The recommended rate under the Ventilation Rate Procedure in ASHRAE Standard 62.1-2004, in many important occupancy types and projects can result in lower ventilation rates than those required by the earlier version of the Standard - Standard 62.1-2001. Applicable Internationally.