Size a solar-powered attic or greenhouse ventilation fan system based on volume and required air changes.
Input Parameters
Results
--
Required Airflow
CFM
--
Fan Power
W
--
PV Panel Size
W
--
Est. Temp Drop
°F
Note: Solar ventilation fans run proportionally to sunlight - more ventilation when it is hottest. 6-10 ACH for attics, 20-40 ACH for greenhouses.
Reference
CFM = (Volume x Air Changes/Hr) / 60
Fan HP = (CFM x Static Pressure) / (6356 x Eff)
Fan Watts = HP x 746
PV Size = Fan Watts / 0.85 DC derating
Temp Drop ~ ACH x 2.5 °F (rule of thumb)