🌍 Air Stream Inputs

Design outdoor dry-bulb
Space / return dry-bulb
Ventilation + economizer OA
Recirculated return airflow
From psychrometric chart or weather data
Space humidity ratio target

📚 OA% Reference Guide

OA% System Type / Condition Notes Mode
10–15% Minimum ventilation only ASHRAE 62.1 minimum; cooling season Mixed
15–30% Typical commercial VAV Standard summer / winter design Mixed
30–70% Partial economizer OA cooler than RA; free cooling assist Econ
70–100% Full / near-full economizer OA at or below setpoint; compressor off Econ
100% 100% OA systems (labs, OR) No recirculation; DOAS / critical spaces 100% OA
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