Update app/hvac_loads.py

app/hvac_loads.py

@@ -618,7 +618,9 @@ class TFMCalculations:
         volume = area * building_height
         is_weekend = False  # Simplified; determine from date in practice
         climate_data = st.session_state.project_data.get("climate_data", {})
-        wind_speed = climate_data.get("hourly_data", [{}])[hour % 24].get("wind_speed", 4.0)
+        wind_speed = max(climate_data.get("hourly_data", [{}])[hour % 24].get("wind_speed", 4.0), 0.0)
+        wind_speed = min(wind_speed, 20.0)
+        wind_direction = climate_data.get("hourly_data", [{}])[hour % 24].get("wind_direction", 0.0)
         outdoor_rh = climate_data.get("hourly_data", [{}])[hour % 24].get("relative_humidity", 50.0)
         indoor_rh = building_info.get("summer_indoor_design_rh" if mode == "cooling" else "winter_indoor_design_rh", 50.0)
         altitude = climate_data.get("location", {}).get("elevation", 0.0)
@@ -636,24 +638,30 @@ class TFMCalculations:
                     ach = system.get("design_flow_rate", 0.3)
                     Q = ach * volume / 3600  # m³/s
                     wind_coeff = 0.23  # LBL model coefficient
-                    ela = Q / (wind_coeff * max(wind_speed, 0.1) ** 2) if wind_speed > 0 else 0.0001 * system_area
-                    infiltration_flow = wind_coeff * ela * (wind_speed ** 2) * fraction
+                    relative_angle = abs((wind_direction - system.get("surface_azimuth", 0.0)) % 360)
+                    wind_coeff_adjusted = wind_coeff * max(0.2, math.cos(math.radians(relative_angle)))
+                    ela = Q / (wind_coeff_adjusted * max(wind_speed, 0.1) ** 2) if wind_speed > 0 else 0.0001 * system_area
+                    infiltration_flow = wind_coeff_adjusted * ela * (wind_speed ** 2) * fraction
                 elif system_type == "Effective Leakage Area":
                     ela = system.get("effective_air_leakage_area", 100.0) / 10000  # cm² to m²
                     stack_coeff = system.get("stack_coefficient", 0.0001)
                     wind_coeff = system.get("wind_coefficient", 0.0001)
+                    relative_angle = abs((wind_direction - system.get("surface_azimuth", 0.0)) % 360)
+                    wind_coeff_adjusted = wind_coeff * max(0.2, math.cos(math.radians(relative_angle)))
                     delta_t_abs = abs(delta_t)
                     Q_stack = stack_coeff * ela * (delta_t_abs ** 0.5)
-                    Q_wind = wind_coeff * ela * (wind_speed ** 2)
+                    Q_wind = wind_coeff_adjusted * ela * (wind_speed ** 2)
                     infiltration_flow = ((Q_stack ** 2 + Q_wind ** 2) ** 0.5) * fraction
                 elif system_type == "Flow Coefficient":
                     c = system.get("flow_coefficient", 0.0001)
                     n = system.get("pressure_exponent", 0.6)
                     stack_coeff = system.get("stack_coefficient", 0.0001)
                     wind_coeff = system.get("wind_coefficient", 0.0001)
+                    relative_angle = abs((wind_direction - system.get("surface_azimuth", 0.0)) % 360)
+                    wind_coeff_adjusted = wind_coeff * max(0.2, math.cos(math.radians(relative_angle)))
                     delta_t_abs = abs(delta_t)
                     delta_p_stack = stack_coeff * delta_t_abs
-                    delta_p_wind = wind_coeff * (wind_speed ** 2)
+                    delta_p_wind = wind_coeff_adjusted * (wind_speed ** 2)
                     delta_p = (delta_p_stack ** 2 + delta_p_wind ** 2) ** 0.5
                     infiltration_flow = c * (delta_p ** n) * system_area * fraction