Natural Ventilation Calculator — Florida Center Model

Monthly Wind Statistics (EPW)

Month	Avg Speed (mph)	Prev. Direction	Arrow	Select

Calculation Results

Floor Area

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ft²

Required Airflow

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CFM

Site Wind Speed

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ft/min

Wind Corr. Factor (ABL)

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combined

Window Design by Facade

Wall	Role	Req. Eff. Area (ft²)	Window Type	Open Factor	Gross Area (ft²)	Eff. Area Provided (ft²)
Total Gross Window Area

Window ÷ Floor ratio: —
Total inlet eff. area: —
Total outlet eff. area: —

Annual ACH Performance · Designed Window Areas

        ACH = 0 when outdoor dry-bulb temperature falls outside the ASHRAE 55 adaptive comfort band
        (80% acceptability, Tlower = 0.31·Tpmt+14.3°C, Tupper = 0.31·Tpmt+21.3°C).
        Tpmt = monthly mean outdoor dry-bulb temperature (approx. 30-day running mean).
        Grey dots on x-axis = windows closed (outside comfort band).
      

Hourly ACH — All 8760 Hours

        
          Comfort hours (coloured by month)
        
          Outside ASHRAE 55 band (ACH = 0)
        
          Design ACH target

Monthly Average ACH (green % = comfort hours)

Wind Roses · Months with Average ACH > 0

        Showing only months where the average delivered ACH > 0 (outdoor conditions within ASHRAE 55 comfort band with sufficient wind).
        Petal length = frequency (% of hours). Colour = mean wind speed (mph) for that sector.
      