Update utils/heating_load.py

utils/heating_load.py

@@ -16,6 +16,12 @@ from utils.heat_transfer import HeatTransferCalculations
 # Import data modules
 from data.building_components import Wall, Roof, Floor, Window, Door, Orientation, ComponentType
 
+# Safely import streamlit for debug mode
+try:
+    import streamlit as st
+except ImportError:
+    st = None
+
 class HeatingLoadCalculator:
     """Class for heating load calculations based on ASHRAE steady-state methods."""
     
@@ -120,7 +126,11 @@ class HeatingLoadCalculator:
         else:
             load = self.heat_transfer.conduction_heat_transfer(floor.u_value, floor.area, delta_t)
         
-        if hasattr(st, 'session_state') and hasattr(st.session_state, 'debug_mode') and st.session_state.debug_mode:
+        # Check debug mode safely
+        debug_mode = False
+        if st is not None and hasattr(st, 'session_state') and hasattr(st.session_state, 'debug_mode'):
+            debug_mode = st.session_state.debug_mode
+        if debug_mode:
             print(f"Debug: Floor {floor.name} load: {load:.2f} W, Delta T: {delta_t:.2f}°C")
         
         return max(0, load)
@@ -211,7 +221,11 @@ class HeatingLoadCalculator:
         sensible_load = self.heat_transfer.infiltration_heat_transfer(flow_rate, delta_t)
         latent_load = self.heat_transfer.infiltration_latent_heat_transfer(flow_rate, delta_w)
         
-        if hasattr(st, 'session_state') and hasattr(st.session_state, 'debug_mode') and st.session_state.debug_mode:
+        # Check debug mode safely
+        debug_mode = False
+        if st is not None and hasattr(st, 'session_state') and hasattr(st.session_state, 'debug_mode'):
+            debug_mode = st.session_state.debug_mode
+        if debug_mode:
             print(f"Debug: Infiltration flow rate: {flow_rate:.6f} m³/s, Sensible load: {sensible_load:.2f} W, Latent load: {latent_load:.2f} W")
         
         return max(0, sensible_load), max(0, latent_load)
@@ -476,8 +490,6 @@ class HeatingLoadCalculator:
 
 # Example usage
 if __name__ == "__main__":
-    import streamlit as st
-    
     calculator = HeatingLoadCalculator()
     
     # Example building components
@@ -508,7 +520,8 @@ if __name__ == "__main__":
         'operating_hours': '8:00-18:00'
     }
     
-    st.session_state.debug_mode = True
+    if st is not None:
+        st.session_state.debug_mode = True
     
     design_loads = calculator.calculate_design_heating_load(components, outdoor_conditions, indoor_conditions, internal_loads)
     summary = calculator.calculate_heating_load_summary(design_loads)