Update data/drapery.py

data/drapery.py

@@ -888,6 +888,41 @@ class WindowHeatGainCalculator:
             cltd_calculator: Instance of CLTDCalculator
         """
         self.cltd_calculator = cltd_calculator
+
+    def _validate_inputs(self, glazing_type: GlazingType, frame_type: FrameType, orientation: str, hour: int, latitude: Any, month: int) -> Tuple[bool, str, float]:
+        """Validate inputs for window/skylight heat gain calculations, following ASHRAE."""
+        valid_orientations = ['North', 'Northeast', 'East', 'Southeast', 'South', 'Southwest', 'West', 'Northwest', 'Horizontal']
+        valid_latitudes = ['24N', '32N', '40N', '48N', '56N']
+        valid_months = list(range(1, 13))
+        valid_glazing_types = [e.value for e in GlazingType]
+        valid_frame_types = [e.value for e in FrameType]
+
+        if glazing_type.value not in valid_glazing_types:
+            return False, f"Invalid glazing type: {glazing_type.value}. Valid types: {valid_glazing_types}", 0.0
+        if frame_type.value not in valid_frame_types:
+            return False, f"Invalid frame type: {frame_type.value}. Valid types: {valid_frame_types}", 0.0
+        if orientation not in valid_orientations:
+            return False, f"Invalid orientation: {orientation}. Valid orientations: {valid_orientations}", 0.0
+        if hour not in range(24):
+            return False, "Hour must be between 0 and 23.", 0.0
+        if month not in valid_months:
+            return False, f"Invalid month: {month}. Valid months: 1-12", 0.0
+
+        # Handle latitude input
+        try:
+            if isinstance(latitude, str):
+                lat_str = latitude.upper().strip().replace('°', '').replace(' ', '')
+                num_part = ''.join(c for c in lat_str if c.isdigit() or c == '.')
+                lat_val = float(num_part)
+                if 'S' in lat_str:
+                    lat_val = -lat_val
+            else:
+                lat_val = float(latitude)
+            abs_lat = abs(lat_val)
+        except (ValueError, TypeError):
+            return False, f"Invalid latitude: {latitude}. Use number (e.g., 40) or string (e.g., '40N')", 0.0
+
+        return True, "Valid inputs.", abs_lat        
     
     def calculate_window_heat_gain(self, area: float, glazing_type: GlazingType, 
                                   frame_type: FrameType, orientation: str, hour: int, 
@@ -906,6 +941,13 @@ class WindowHeatGainCalculator:
         Returns:
             Tuple of (conduction_heat_gain, solar_heat_gain) in Watts
         """
+        # Validate inputs
+        is_valid, error_msg, lat_val = self._validate_inputs(
+            glazing_type, frame_type, orientation, hour, self.cltd_calculator.latitude.value, self.cltd_calculator.month
+        )
+        if not is_valid:
+            raise ValueError(error_msg)
+
         # Get U-factor
         u_factor = WINDOW_U_FACTORS.get((glazing_type, frame_type), 7.22)
         
@@ -919,13 +961,17 @@ class WindowHeatGainCalculator:
         conduction_reduction = drapery.get_conduction_reduction() if drapery and drapery.enabled else 0.0
         conduction_heat_gain = area * u_factor * cltd * (1.0 - conduction_reduction)
         
-        # Get SCL from ASHRAE tables
-        scl = self.cltd_calculator.ashrae_tables.get_scl(
-            latitude=self.cltd_calculator.latitude.value,
-            orientation=orientation,
-            hour=hour,
-            month=self.cltd_calculator.month
-        )
+        # Interpolate SCL for latitude
+        latitudes = [24, 32, 40, 48, 56]
+        lat1 = max([lat for lat in latitudes if lat <= lat_val], default=24)
+        lat2 = min([lat for lat in latitudes if lat >= lat_val], default=56)
+        scl1 = self.cltd_calculator.ashrae_tables.get_scl(f"{lat1}N", orientation, hour, self.cltd_calculator.month)
+        scl2 = self.cltd_calculator.ashrae_tables.get_scl(f"{lat2}N", orientation, hour, self.cltd_calculator.month)
+        if lat1 == lat2:
+            scl = scl1
+        else:
+            weight = (lat_val - lat1) / (lat2 - lat1)
+            scl = scl1 + weight * (scl2 - scl1)
         
         # Apply drapery shading coefficient
         shading_coefficient = drapery.get_shading_coefficient(shgc) if drapery and drapery.enabled else 1.0
@@ -949,6 +995,13 @@ class WindowHeatGainCalculator:
         Returns:
             Tuple of (conduction_heat_gain, solar_heat_gain) in Watts
         """
+        # Validate inputs
+        is_valid, error_msg, lat_val = self._validate_inputs(
+            glazing_type, frame_type, 'Horizontal', hour, self.cltd_calculator.latitude.value, self.cltd_calculator.month
+        )
+        if not is_valid:
+            raise ValueError(error_msg)
+        
         # Get U-factor
         u_factor = SKYLIGHT_U_FACTORS.get((glazing_type, frame_type), 7.79)
         
@@ -962,13 +1015,17 @@ class WindowHeatGainCalculator:
         conduction_reduction = drapery.get_conduction_reduction() if drapery and drapery.enabled else 0.0
         conduction_heat_gain = area * u_factor * cltd * (1.0 - conduction_reduction)
         
-        # Get SCL for skylight (horizontal)
-        scl = self.cltd_calculator.ashrae_tables.get_scl(
-            latitude=self.cltd_calculator.latitude.value,
-            orientation='Horizontal',
-            hour=hour,
-            month=self.cltd_calculator.month
-        )
+        # Interpolate SCL for latitude
+        latitudes = [24, 32, 40, 48, 56]
+        lat1 = max([lat for lat in latitudes if lat <= lat_val], default=24)
+        lat2 = min([lat for lat in latitudes if lat >= lat_val], default=56)
+        scl1 = self.cltd_calculator.ashrae_tables.get_scl(f"{lat1}N", 'Horizontal', hour, self.cltd_calculator.month)
+        scl2 = self.cltd_calculator.ashrae_tables.get_scl(f"{lat2}N", 'Horizontal', hour, self.cltd_calculator.month)
+        if lat1 == lat2:
+            scl = scl1
+        else:
+            weight = (lat_val - lat1) / (lat2 - lat1)
+            scl = scl1 + weight * (scl2 - scl1)
         
         # Apply drapery shading coefficient
         shading_coefficient = drapery.get_shading_coefficient(shgc) if drapery and drapery.enabled else 1.0