November Chapter Meeting – Support ASHRAE Research

Main Session

Hoy Bohanon, Member, Hoy Bohanon Engineering PLLC, Clemmons, NC

What will ASHRAE Standard 62.1-2019 Look Like with the Proposed Changes to the IAQA, NVP and VRP?

ASHRAE 62.1 is fundamentally changed from the version of 62 that was the basis for many building codes. As the new version works its way into the codes, there are also many associated requirements in addition to the ventilation rates. ASHRAE Standard 62.1 is under continuous maintenance. That means that every 18 months, there are changes published to the standard. This presentation provides an overview of the standard with emphasis on the most recent changes.

What will ASHRAE Standard 62.1-2019 Look Like with the Proposed Changes to the IAQA, NVP and VRP?

Track: Fundamentals and Applications

• Know that there are major changes proposed in Standard 62.1

• Understand the new Natural Ventilation Rate Procedure

• Understand the new Indoor Air Quality Procedure

• Understand the changes in the Ventilation Rate Procedure

SSPC 62.1 is making major modifications to the standard that need to be communicated to the membership. These include a new Natural Ventilation Rate Procedure, a new Indoor Air Quality Procedure and changes to the Ventilation Rate Procedure that will have major impact on the way the standard will be applied.

1. Overall Direction for Modifications to Standard 62.1

SSPC 62.1’s mission is to maintain a design standard providing ventilation procedures for acceptable indoor air safety and quality for the built environment. After a year of discussions, the committee made an important decision. That decision is to make the quality of indoor air more comparable between the different pathways. This presentation addresses the modifications to ASHRAE standard 62.1.

2. The New NVP

The natural ventilation procedure has changed over the years in 62.1. It was relocated from section 5 to section 6 and became a ventilation procedure. It was recently modified to require mechanical ventilation with certain exceptions. This addendum provides specific requirements for the exception by providing a clear compliance path. It also recognizes that there are inherent health issues with outdoor air in many locations in the world and updates the prescriptive requirements based on recent studies and airflow evaluations.

3. The New IAQP

This presentation discusses the design requirements of the New IAQP. Those requirements include; identification of contaminants of concern, determining indoor and outdoor sources, identifying a concentration limit and exposure period, specifying percentage of building occupants to be satisfied with perceived IAQ and performing a mass balance analysis for selected compounds.

4. Changes to the VRP

Ventilation Rate Procedure is the prescriptive design procedure presented in Section 6.2, in which outdoor air intake rates are determined based on space type/application, occupancy level, and floor area shall be permitted to be used for any zone or system. Informative Note: The Ventilation Rate Procedure minimum rates are based on contaminant sources and source strengths that are typical for the listed occupancy categories. The requirements for atypical sources are spelled out in new addenda. There is a simplified VRP that incorporates a default Ev. This helps designers who do not wish to perform the more complex calculations in Appendix A. The use of this simplified procedure is described

Tech Session

Marwa Zaatari, University of Texas at Austin, Austin, TX

In the technical session, Marwa will present the following:

Moving from perspective to performance-based approaches:

Instead of continuously replacing indoor air with outside air to expel indoor-generated contaminants and manage indoor air quality (IAQ), indoor air can be cleaned using regenerative sorbents. By cleansing the indoor air, sorbent-based air cleaning minimizes the amount of outside air required to maintain IAQ, thereby reducing the load on HVAC systems and achieving energy savings.

Learning objectives include:

• When and how to apply ASHRAE 62.1 IAQP

• Building code compliance using IAQP

• Impact on HVAC capacity requirements

• Energy efficiency calculations

• Indoor air quality controls

• LEED Compliance