Title 24: natural ventilation and chilled beams

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Since Eric has not "corrected" Mathew, I will:
The eQuest POWERED induction unit SYSTEM (i.e. TYPE = PIU) just refers to fan-powered reHEAT boxes in VAV systems. The eQuest INDUCTION UNIT SYSTEM models an archaic system that can be made somewhat analogous to modern ACTIVE chilled beam systems by overriding some of the system defaults. However, no matter what the user specifies in the zone, this simulates constant volume airflow to all connected zones whenever the central AHU is active.

The natural ventilation system keywords only apply to PSZ and related SYSTEM types, so can only be utilized in the most basic small commercial building models. And I'm fairly certain wind direction is not considered even by the more sophisticated S-G method, among other shortcomings.

Fred Porter
Architectural Energy

Eric, please correct me if I'm wrong but I though a chilled beam was an
induction unit; and eQuest has both powered and non-powered induction
units. Also, if you look at the HVAC units you input there is an Outdoor
Air tab that will let you specify either an Air Change Rate or
Sherman-Grimsrud Method (based on wind) for Natural Ventilation. Either
method requires the creation of schedules, but I've found both to be

Matthew Higgins, LEED AP + ASHRAE-HPBD

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