Standard 62.1: A VAV Dynamic Reset Approach
ASHRAE Standard 62.1 “Ventilation for Acceptable Indoor Air Quality,” provides minimum design requirements for proper ventilation in commercial, institutional and hi-rise residential buildings. It allows optional “dynamic reset” controls to help match current system ventilation capacity to current load, but leaves design details for such controls to the designer. ASHRAE Standard 90.1 and ASHRAE Standard 189.1, on the other hand, both require demand controlled ventilation (DCV) for some zones, but they too, leave out design details. While relatively simple for single-zone systems, DCV can be much more complex for multiple-zone systems.
1. ASHRAE Standard 62.1-2010 DCV in Multiple-Zone Systems: Ventilation Reset Control
Agenda
Presenter: Dennis Stanke, Trane Staff Applications Engineer, FASHRAE
Abstract:
ASHRAE Standard 62.1 “Ventilation for Acceptable Indoor Air Quality,” provides minimum outdoor airflow
requirements at design conditions. However, ASHRAE Standard 90.1 requires some systems to be operated so
that current ventilation capacity modulates to match current ventilation load (i.e., demand). Standard 62.1
allows optional “dynamic reset” controls to help match current capacity to load, but design details for such
controls are left to the designer. One design approached, described in this presentation, combines ventilation
reset control at the system level with various zone-level “demand controlled ventilation” strategies.
Learning objectives
After viewing this program Participants will be able to:
1. Apply ventilation system design calculations for three ventilation systems: single-zone,
100% outdoor air, and multiple-zone systems (MZS)
2. Summarize how demand controlled ventilation (DCV) can be incorporated in all three ventilation systems
3. Apply dynamic reset to VAV systems using ventilation reset control, which responds to changes in
system ventilation efficiency
4. Apply dynamic reset to VAV systems by combining zone-level DCV with system-level ventilation reset
control, to respond to both changes in zone population and changes in system ventilation efficiency
Agenda
6.2.2 Zone calculations (zone OA)
6.2.3 Single-zone systems (OA intake)
6.2.4 100% OA systems (OA intake)
6.2.5 Multiple-zone recirc systems (OA intake)
6.2.7 Dynamic reset
Wrap-up/discussion