From 51f4d8d2b6331c880576376b758afb4d61fa29dd Mon Sep 17 00:00:00 2001
From: omicron <omicron.me@protonmail.com>
Date: Mon, 8 Jun 2026 14:47:36 +0200
Subject: [PATCH] Add boundary condition coefficient to Surface HT calculation

---
 interfaces.py | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/interfaces.py b/interfaces.py
index f504561..e251378 100644
--- a/interfaces.py
+++ b/interfaces.py
@@ -19,9 +19,10 @@ class Interface(ABC):
 
 
 class Surface(Interface):
-    def __init__(self, name: str, area: float):
+    def __init__(self, name: str, area: float, b: float = 1.0):
         self.name = name
         self.area = area
+        self.b = b
 
     @property
     @abstractmethod
@@ -29,7 +30,7 @@ class Surface(Interface):
 
     @property
     def HT(self) -> float:
-        return self.U * self.area
+        return self.b * self.U * self.area
 
 
 class LinearThermalBridge(Interface):
@@ -61,8 +62,9 @@ class LayeredSurface(Surface):
         layers: list[Layer],
         r_surface_1: float,
         r_surface_2: float,
+        b: float = 1.0,
     ):
-        super().__init__(name, area)
+        super().__init__(name, area, b)
         self.layers = layers
         self.r_surface_1 = r_surface_1
         self.r_surface_2 = r_surface_2
@@ -75,8 +77,8 @@ class LayeredSurface(Surface):
 
 
 class FixedUSurface(Surface):
-    def __init__(self, name: str, area: float, u_value: float):
-        super().__init__(name, area)
+    def __init__(self, name: str, area: float, u_value: float, b: float = 1.0):
+        super().__init__(name, area, b)
         self.u_value = u_value
 
     @property