diff --git a/docs/source_docs/user_guide/inputs/boundary_conditions.rst b/docs/source_docs/user_guide/inputs/boundary_conditions.rst
index bd0a719a4c7b3eac5fc133b05124c3a5dadcc4f0..0a899de2fd1d5b86652236278f69b82bb30588e7 100644
--- a/docs/source_docs/user_guide/inputs/boundary_conditions.rst
+++ b/docs/source_docs/user_guide/inputs/boundary_conditions.rst
@@ -285,7 +285,13 @@ temperature sees an abrupt spike from 300 up to 500 at t = 3s and then back
 down again after 4s. Note that the timestep is not adjusted to sync with
 transient BCs.
 
-.. image:: ./images/transient-bc.png
+.. figure:: ./images/transient-bc.png
+   :height: 4in
+   :align: center
+   :alt: Plot of boundary conditions versus time. Fluid velocity increases linearly from 0 to 15 cm/s over the first 3 seconds and then remains constant. Temperature stays at 300 K from 0 to 3 seconds, rises abruptly to 500 K between 3 and 4 seconds, and then returns to 300 K after 4 seconds.
+
+   Linear velocity ramp to 15 cm/s (0–3 s), constant thereafter; temperature step from 300 K to 500 K (3–4 s) then return to 300 K
+
 
 Thermal boundary conditions
 ---------------------------
@@ -328,12 +334,13 @@ inputs defined using the prefix ``bc.[region_name].eb``.
 |                      | A valid is required for ``constant`` EB temperature model.            |             |           |
 +----------------------+-----------------------------------------------------------------------+-------------+-----------+
 
-The conjugate heat transfer model approximates heat transfer through the embedded boundary using one-dimensional,
-steady-state conduction. The external environment is treated as a thermal reservoir with a constant temperature
-in both space and time. This approach is illustrated in :numref:`fig_conjugate_heat_transfer_bc`, where heat flows
-through a series of thermal resistances: from the fluid to the inner wall surface, through the wall, and finally
-to the environment. The direction of heat transfer---into or out of the system---is governed by the temperature
-gradient between the fluid and the surroundings.
+The conjugate heat transfer model approximates heat transfer through the embedded boundary using a one-dimensional thermal
+resistance representation. By default, the wall temperature is computed from an algebraic heat balance; optionally, a
+lumped-capacity transient wall model can be enabled.
+
+The external environment is treated as a thermal reservoir with constant temperature :math:`T_{\infty}`. Heat is
+transferred from the fluid to the inner wall surface, through the wall, and then from the outer wall surface to
+the environment, as illustrated in :numref:`fig_conjugate_heat_transfer_bc`.
 
 .. _fig_conjugate_heat_transfer_bc:
 
@@ -344,22 +351,38 @@ gradient between the fluid and the surroundings.
 
    Schematic of the conjugate heat transfer boundary condition.
 
-An effective resistance is calculated based on the convective heat transfer coefficient between the fluid
-and wall, :math:`h_{int}`, conduction through the wall with thickness :math:`L_w` and thermal conductivity
-:math:`\kappa_w`, and convective heat transfer from the exterior wall to the environment :math:`h_{ext}`.
+The effective outward thermal conductance per unit area is
 
 .. math::
 
-   R_{eff} = \left( \frac{1}{h_{int}} + \frac{L_w}{\kappa_w} + \frac{1}{h_{ext}} \right)^{-1}
+   G_{out} = \left( \frac{L_w}{\kappa_w} + \frac{1}{h_{ext}} \right)^{-1}
+
+where :math:`L_w` is the wall thickness, :math:`\kappa_w` is the wall thermal conductivity,
+and :math:`h_{ext}` is the external convective heat transfer coefficient. This expression
+represents the combined resistance of conduction through the wall and convection from the
+outer wall surface to the environment.
 
-The interior wall temperature is determined by balancing the heat flux contributions from internal
-convection, wall conduction, and external convection, resulting in a closed-form expression based
-on the effective thermal resistance of the system.
+For the zero-capacity wall model, the inner wall temperature is determined from an algebraic
+heat balance between internal convection, radiation, and heat transfer to the environment:
 
 .. math::
 
-   T_{w,int} = T_f - \frac{1}{h_{int}}\left[ \frac{T_f - T_{\infty}}{R_{eff}} \right]
+   T_{w,int} = \frac{ h_{int} T_f - q_{rad} + G_{out} T_{\infty}}{h_{int} + G_{out}}
+
+where :math:`h_{int}` is the internal convective heat transfer coefficient. Positive :math:`q_{rad}`
+denotes radiative heat loss from the wall. By default, the CHT-1D wall has no thermal storage,
+so the wall temperature responds instantaneously to changes in the local heat balance.
 
+If a wall heat capacity :math:`C_A` [J/(m\ :sup:`2`\ K)] is specified, the wall is modeled as a lumped thermal
+mass with a single spatially uniform temperature. In that case, the wall temperature evolves according to
+
+.. math::
+
+   C_A \frac{dT_{w,int}}{dt} = h_{int} \left( T_f - T_{w,int} \right) - q_{rad} - G_{out} \left( T_{w,int} - T_{\infty} \right)
+
+In this lumped-capacity approximation, the inner and outer wall temperatures are not resolved separately; instead,
+the wall is represented by a single transient temperature. When :math:`C_A = 0` or is not specified, the algebraic
+wall temperature model is used.
 
 The model settings are defined using the prefix ``bc.[region_name].eb.temperature.CHT-1D``:
 
@@ -389,6 +412,8 @@ The model settings are defined using the prefix ``bc.[region_name].eb.temperatur
 +----------------------------+------------------------------------------------------------------------+-------------+-----------+
 | wall.thickness             | Wall thickness.                                                        | Real        | None      |
 +----------------------------+------------------------------------------------------------------------+-------------+-----------+
+| wall.heat_capacity         | Lumped wall heat capacity per area [J/(m\ :sup:`2`\ K)]                | Real        |  0.       |
++----------------------------+------------------------------------------------------------------------+-------------+-----------+
 | phase_averaged_temperature | Use a phase averaged temperature for simulations containing particles. | Bool        | false     |
 |                            | The phase averaged temperature is computed as the volume fraction      |             |           |
 |                            | weighted sum of the fluid and averaged particle temperatures.          |             |           |
diff --git a/docs/source_docs/user_guide/inputs/output/plotting.rst b/docs/source_docs/user_guide/inputs/output/plotting.rst
index 4770b834435edc6d31d25c41d193778d99b50850..4c9aa3d5eae4e9680f22d38280400fb30ed9558b 100644
--- a/docs/source_docs/user_guide/inputs/output/plotting.rst
+++ b/docs/source_docs/user_guide/inputs/output/plotting.rst
@@ -73,6 +73,8 @@ The following inputs must be preceded by the prefix ``mfix`` and control which v
 +---------------------+-----------------------------------------------------------------------+-------------+-----------+
 | plt_X_g             | Plot fluid species mass fractions.                                    |    Int      | 0         |
 +---------------------+-----------------------------------------------------------------------+-------------+-----------+
+| plt_T_eb            | Plot EB wall temperature. Only applicable for CHT-1D BCs.             |    Int      | 0         |
++---------------------+-----------------------------------------------------------------------+-------------+-----------+
 
 The following inputs must be preceded by the prefix ``mfix.solids`` and allow to write additional plotfiles which
 contain only solids variables in specific regions at fixed timesteps or approximated simulation times.