Update data/ashrae_tables.py

data/ashrae_tables.py

@@ -1167,16 +1167,28 @@ class ASHRAETables:
       weight = (latitude - lat1) / (lat2 - lat1)
       return scl1 + weight * (scl2 - scl1)
 
-    def apply_cltd_corrections(self, cltd: float, lm: float, k: float, f: float) -> float:
+    def apply_cltd_corrections(self, cltd: float, lm: float, solar_absorptivity: float, f: float) -> float:
         """
         Apply corrections to CLTD based on ASHRAE correction factors.
         Args:
             cltd: Base CLTD value.
             lm: Latitude-month correction factor.
-            k: Color correction factor.
+            solar_absorptivity: Solar absorptivity of the surface (0.0 to 1.0).
             f: Fenestration correction factor.
         Returns: Corrected CLTD value.
         """
+        correction_factors = self._load_color_correction()
+        absorptivities = sorted(correction_factors.keys())
+        if solar_absorptivity in correction_factors:
+            k = correction_factors[solar_absorptivity]
+        else:
+            low_a = max([a for a in absorptivities if a <= solar_absorptivity], default=absorptivities[0])
+            high_a = min([a for a in absorptivities if a >= solar_absorptivity], default=absorptivities[-1])
+            if low_a == high_a:
+                k = correction_factors[low_a]
+            else:
+                weight = (solar_absorptivity - low_a) / (high_a - low_a)
+                k = correction_factors[low_a] + weight * (correction_factors[high_a] - correction_factors[low_a])
         return cltd + lm + (k - 1) * cltd + (f - 1) * cltd
 
     def visualize_cltd(self, element_type: str, group: str, orientation: str, latitude: float):