Update data/ashrae_tables.py

data/ashrae_tables.py

@@ -1078,16 +1078,17 @@ class ASHRAETables:
             raise ValueError(f"Invalid zone {zone} for CLF equipment")
         
     @lru_cache(maxsize=1000)
-    def get_cltd(self, element_type: str, group: str, orientation: str, hour: int, latitude: float) -> float:
+    def get_cltd(self, element_type: str, group: str, orientation: str, hour: int, latitude: float, solar_absorptivity: float = 0.6) -> float:
         """
-        Retrieve CLTD value for a given element type, group, orientation, hour, and latitude with interpolation.
+        Retrieve CLTD value for a given element type, group, orientation, hour, latitude, and solar absorptivity with interpolation.
         Args:
             element_type: 'wall' or 'roof'.
             group: Group identifier (e.g., 'A', 'B', ..., 'H' for walls; 'A', 'B', ..., 'G' for roofs).
             orientation: Orientation (e.g., 'North', 'East', 'Horizontal' for roofs).
             hour: Hour of the day (0-23).
             latitude: Latitude in degrees (24 to 56).
-        Returns: Interpolated CLTD value.
+            solar_absorptivity: Solar absorptivity of the surface (0.0 to 1.0, default 0.6 for Medium).
+        Returns: Interpolated and corrected CLTD value.
         Raises:
             ValueError: If inputs are invalid or out of range.
         """
@@ -1098,9 +1099,16 @@ class ASHRAETables:
         if not 24 <= latitude <= 56:
             raise ValueError("Latitude must be between 24 and 56 degrees")
 
+        # Validate inputs
+        is_wall = element_type == 'wall'
+        latitude_str = f"{int(latitude)}N"
+        month = 'Jul'  # Default to July for CLTD calculations
+        is_valid, error_msg = self._validate_cltd_inputs(group, orientation, hour, latitude_str, month, solar_absorptivity, is_wall)
+        if not is_valid:
+            raise ValueError(error_msg)
+
         # Available latitudes
-        latitudes = [24, 32, 36, 44, 56]
-        # Find the two closest latitudes for interpolation
+        latitudes = [24, 32, 40, 48, 56]
         lat1, lat2 = max([lat for lat in latitudes if lat <= latitude], default=24), min([lat for lat in latitudes if lat >= latitude], default=56)
         
         # Load the appropriate table
@@ -1119,9 +1127,16 @@ class ASHRAETables:
 
         # Linear interpolation
         if lat1 == lat2:
-            return cltd1
-        weight = (latitude - lat1) / (lat2 - lat1)
-        return cltd1 + weight * (cltd2 - cltd1)
+            cltd = cltd1
+        else:
+            weight = (latitude - lat1) / (lat2 - lat1)
+            cltd = cltd1 + weight * (cltd2 - cltd1)
+
+        # Apply corrections
+        lm = self.month_correction.get(latitude_str, {}).get(month, 0.0)
+        f = self._load_fenestration_correction().get('Standard', 1.0)
+        corrected_cltd = self.apply_cltd_corrections(cltd, lm, solar_absorptivity, f)
+        return corrected_cltd
 
     @lru_cache(maxsize=1000)
     def get_scl(self, orientation: str, hour: int, latitude: float, month: str = 'Jul') -> float: