diff --git a/cara/apps/calculator/model_generator.py b/cara/apps/calculator/model_generator.py
index c4593b49..ec770589 100644
--- a/cara/apps/calculator/model_generator.py
+++ b/cara/apps/calculator/model_generator.py
@@ -244,7 +244,7 @@ class FormData:
             humidity = 0.3
         else:
             humidity = 0.5
-        room = models.Room(volume=volume, humidity=humidity)
+        room = models.Room(volume=volume, inside_temp=models.PiecewiseConstant((0, 24), (293,)), humidity=humidity)
 
         infected_population = self.infected_population()
         
@@ -329,13 +329,11 @@ class FormData:
                 window_interval = always_on
 
             outside_temp = self.outside_temp()
-            inside_temp = models.PiecewiseConstant((0, 24), (293,))
 
             ventilation: models.Ventilation
             if self.window_type == 'window_sliding':
                 ventilation = models.SlidingWindow(
                     active=window_interval,
-                    inside_temp=inside_temp,
                     outside_temp=outside_temp,
                     window_height=self.window_height,
                     opening_length=self.opening_distance,
@@ -344,7 +342,6 @@ class FormData:
             elif self.window_type == 'window_hinged':
                 ventilation = models.HingedWindow(
                     active=window_interval,
-                    inside_temp=inside_temp,
                     outside_temp=outside_temp,
                     window_height=self.window_height,
                     window_width=self.window_width,
diff --git a/cara/apps/expert.py b/cara/apps/expert.py
index 84beed27..84690d3c 100644
--- a/cara/apps/expert.py
+++ b/cara/apps/expert.py
@@ -243,19 +243,29 @@ class ModelWidgets(View):
 
     def _build_room(self, node):
         room_volume = widgets.IntSlider(value=node.volume, min=10, max=150)
+        inside_temp = widgets.IntSlider(value=node.inside_temp.values[0]-273.15, min=15., max=25.)
 
-        def on_value_change(change):
+        def on_volume_change(change):
             node.volume = change['new']
 
+        def on_insidetemp_change(change):
+            node.inside_temp.values = (change['new']+273.15,)
+
         # TODO: Link the state back to the widget, not just the other way around.
-        room_volume.observe(on_value_change, names=['value'])
+        room_volume.observe(on_volume_change, names=['value'])
+        inside_temp.observe(on_insidetemp_change, names=['value'])
+        
         def on_state_change():
             room_volume.value = node.volume
+            inside_temp.value = node.inside_temp
+            
         node.dcs_observe(on_state_change)
 
         widget = collapsible(
             [widget_group(
-                [[widgets.Label('Room volume (m³)'), room_volume]]
+                [[widgets.Label('Room volume (m³)'), room_volume], 
+                 [widgets.Label('Inside temperature (℃)'), inside_temp],
+                ]
             )],
             title='Specification of workplace',
         )
@@ -281,7 +291,6 @@ class ModelWidgets(View):
     def _build_window(self, node) -> WidgetGroup:
         period = widgets.IntSlider(value=node.active.period, min=0, max=240)
         interval = widgets.IntSlider(value=node.active.duration, min=0, max=240)
-        inside_temp = widgets.IntSlider(value=node.inside_temp.values[0]-273.15, min=15., max=25.)
 
         def on_period_change(change):
             node.active.period = change['new']
@@ -289,13 +298,9 @@ class ModelWidgets(View):
         def on_interval_change(change):
             node.active.duration = change['new']
 
-        def insidetemp_change(change):
-            node.inside_temp.values = (change['new']+273.15,)
-
         # TODO: Link the state back to the widget, not just the other way around.
         period.observe(on_period_change, names=['value'])
         interval.observe(on_interval_change, names=['value'])
-        inside_temp.observe(insidetemp_change, names=['value'])
 
         outsidetemp_widgets = {
             'Fixed': self._build_outsidetemp(node.outside_temp),
@@ -327,10 +332,6 @@ class ModelWidgets(View):
                     widgets.Label('Duration of opening (minutes)', layout=auto_width),
                     interval,
                 ),
-                (
-                    widgets.Label('Inside temperature (℃)', layout=auto_width),
-                    inside_temp,
-                ),
                 (
                     widgets.Label('Outside temperature scheme', layout=auto_width),
                     outsidetemp_w,
@@ -485,10 +486,9 @@ class ModelWidgets(View):
 
 baseline_model = models.ExposureModel(
     concentration_model=models.ConcentrationModel(
-        room=models.Room(volume=75),
+        room=models.Room(volume=75, inside_temp=models.PiecewiseConstant((0., 24.), (293.15,))),
         ventilation=models.SlidingWindow(
             active=models.PeriodicInterval(period=120, duration=15),
-            inside_temp=models.PiecewiseConstant((0., 24.), (293.15,)),
             outside_temp=models.PiecewiseConstant((0., 24.), (283.15,)),
             window_height=1.6, opening_length=0.6,
         ),
diff --git a/cara/models.py b/cara/models.py
index 40e8a422..d696067a 100644
--- a/cara/models.py
+++ b/cara/models.py
@@ -57,15 +57,6 @@ _VectorisedFloat = typing.Union[float, np.ndarray]
 _VectorisedInt = typing.Union[int, np.ndarray]
 
 
-@dataclass(frozen=True)
-class Room:
-    #: The total volume of the room
-    volume: _VectorisedFloat
-
-    #: The humidity in the room (from 0 to 1 - e.g. 0.5 is 50% humidity)
-    humidity: _VectorisedFloat = 0.5
-
-
 Time_t = typing.TypeVar('Time_t', float, int)
 BoundaryPair_t = typing.Tuple[Time_t, Time_t]
 BoundarySequence_t = typing.Union[typing.Tuple[BoundaryPair_t, ...], typing.Tuple]
@@ -195,6 +186,18 @@ class PiecewiseConstant:
         )
 
 
+@dataclass(frozen=True)
+class Room:
+    #: The total volume of the room
+    volume: _VectorisedFloat
+
+    #: The temperature inside the room (Kelvin).
+    inside_temp: PiecewiseConstant = PiecewiseConstant((0, 24), (293,))
+
+    #: The humidity in the room (from 0 to 1 - e.g. 0.5 is 50% humidity)
+    humidity: _VectorisedFloat = 0.5
+
+
 @dataclass(frozen=True)
 class _VentilationBase:
     """
@@ -207,7 +210,7 @@ class _VentilationBase:
     mechanical air exchange through a filter.
 
     """
-    def transition_times(self) -> typing.Set[float]:
+    def transition_times(self, room: Room) -> typing.Set[float]:
         raise NotImplementedError("Subclass must implement")
 
     def air_exchange(self, room: Room, time: float) -> _VectorisedFloat:
@@ -228,7 +231,7 @@ class Ventilation(_VentilationBase):
     #: The interval in which the ventilation is active.
     active: Interval
 
-    def transition_times(self) -> typing.Set[float]:
+    def transition_times(self, room: Room) -> typing.Set[float]:
         return self.active.transition_times()
 
 
@@ -243,10 +246,10 @@ class MultipleVentilation(_VentilationBase):
     """
     ventilations: typing.Tuple[_VentilationBase, ...]
 
-    def transition_times(self) -> typing.Set[float]:
+    def transition_times(self, room: Room) -> typing.Set[float]:
         transitions = set()
         for ventilation in self.ventilations:
-            transitions.update(ventilation.transition_times())
+            transitions.update(ventilation.transition_times(room))
         return transitions
 
     def air_exchange(self, room: Room, time: float) -> _VectorisedFloat:
@@ -265,9 +268,6 @@ class WindowOpening(Ventilation):
     #: The interval in which the window is open.
     active: Interval
 
-    #: The temperature inside the room (Kelvin).
-    inside_temp: PiecewiseConstant
-
     #: The temperature outside of the window (Kelvin).
     outside_temp: PiecewiseConstant
 
@@ -292,9 +292,10 @@ class WindowOpening(Ventilation):
         """
         raise NotImplementedError("Unknown discharge coefficient")
 
-    def transition_times(self) -> typing.Set[float]:
-        transitions = super().transition_times()
-        transitions.update(self.inside_temp.transition_times)
+    def transition_times(self, room: Room) -> typing.Set[float]:
+        transitions = super().transition_times(room)
+        print(room.inside_temp.transition_times)
+        transitions.update(room.inside_temp.transition_times)
         transitions.update(self.outside_temp.transition_times)
         return transitions
 
@@ -304,7 +305,7 @@ class WindowOpening(Ventilation):
             return 0.
 
         # Reminder, no dependence on time in the resulting calculation.
-        inside_temp: _VectorisedFloat = self.inside_temp.value(time)
+        inside_temp: _VectorisedFloat = room.inside_temp.value(time)
         outside_temp: _VectorisedFloat = self.outside_temp.value(time)
 
         # The inside_temperature is forced to be always at least min_deltaT degree
@@ -439,20 +440,20 @@ class Virus:
     #: Pre-populated examples of Viruses.
     types: typing.ClassVar[typing.Dict[str, "Virus"]]
 
-    def halflife(self, humidity: _VectorisedFloat, inside_temp: _VectorisedFloat) -> _VectorisedFloat:
+    def halflife(self, humidity: _VectorisedFloat, inside_temp: PiecewiseConstant, time: float) -> _VectorisedFloat:
         # Biological decay (inactivation of the virus in air) - virus 
         # dependent and function of humidity
         raise NotImplementedError
 
-    def decay_constant(self, humidity: _VectorisedFloat, inside_temp: _VectorisedFloat) -> _VectorisedFloat:
+    def decay_constant(self, humidity: _VectorisedFloat, inside_temp: PiecewiseConstant, time: float) -> _VectorisedFloat:
         # Viral inactivation per hour (h^-1) (function of humidity)
-        return np.log(2) / self.halflife(humidity, inside_temp)
+        return np.log(2) / self.halflife(humidity, inside_temp, time)
 
 
 @dataclass(frozen=True)
 class SARSCoV2(Virus):
 
-    def halflife(self, humidity: _VectorisedFloat, inside_temp: _VectorisedFloat) -> _VectorisedFloat:
+    def halflife(self, humidity: _VectorisedFloat, inside_temp: PiecewiseConstant, time: float) -> _VectorisedFloat:
         """
         Half-life changes with humidity level. Here is implemented a simple
         piecewise constant model (for more details see A. Henriques et al,
@@ -460,7 +461,8 @@ class SARSCoV2(Virus):
         """
         # Updated to use the formula from Dabish et al. https://doi.org/10.1080/02786826.2020.1829536
         # with a minimum at hl = 1.1
-        return max(1.1, (0.693/(0.16030 + 0.04018((inside_temp-20.615)/10.585)+0.2176((humidity-45.235)/28.665)+0.1)))
+        inside_temp = inside_temp.value(time)
+        return max(1.1, (0.693/(0.16030 + 0.04018*(((inside_temp-274.15)-20.615)/10.585)+0.02176*((humidity-45.235)/28.665)+0.1)))
         
 
 Virus.types = {
@@ -919,7 +921,7 @@ class ConcentrationModel:
         k = (vg * 3600) / h
         #todo: Inside_temp needs to be exposed/added to the room;
         return (
-            k + self.virus.decay_constant(self.room.humidity, self.room.inside_temp)
+            k + self.virus.decay_constant(self.room.humidity, self.room.inside_temp, time)
             + self.ventilation.air_exchange(self.room, time)
         )
 
@@ -950,7 +952,7 @@ class ConcentrationModel:
         """
         state_change_times = {0.}
         state_change_times.update(self.infected.presence.transition_times())
-        state_change_times.update(self.ventilation.transition_times())
+        state_change_times.update(self.ventilation.transition_times(self.room))
         return sorted(state_change_times)
 
     @method_cache
diff --git a/cara/tests/apps/calculator/test_model_generator.py b/cara/tests/apps/calculator/test_model_generator.py
index 5cc9e409..6f118a8e 100644
--- a/cara/tests/apps/calculator/test_model_generator.py
+++ b/cara/tests/apps/calculator/test_model_generator.py
@@ -60,7 +60,6 @@ def test_ventilation_slidingwindow(baseline_form: model_generator.FormData):
 
     window = models.SlidingWindow(
         active=models.PeriodicInterval(period=120, duration=10, start=minutes_since_midnight(9 * 60)),
-        inside_temp=models.PiecewiseConstant((0, 24), (293,)),
         outside_temp=baseline_window.outside_temp,
         window_height=1.6, opening_length=0.6,
     )
@@ -92,7 +91,6 @@ def test_ventilation_hingedwindow(baseline_form: model_generator.FormData):
 
     window = models.HingedWindow(
         active=models.PeriodicInterval(period=120, duration=10, start=minutes_since_midnight(9 * 60)),
-        inside_temp=models.PiecewiseConstant((0, 24), (293,)),
         outside_temp=baseline_window.outside_temp,
         window_height=1.6, window_width=1., opening_length=0.6,
     )
@@ -106,7 +104,7 @@ def test_ventilation_hingedwindow(baseline_form: model_generator.FormData):
 
 
 def test_ventilation_mechanical(baseline_form: model_generator.FormData):
-    room = models.Room(75)
+    room = models.Room(volume=75, inside_temp=models.PiecewiseConstant((0, 24), (293,)))
     mech = models.HVACMechanical(
         active=models.PeriodicInterval(period=120, duration=120),
         q_air_mech=500.,
@@ -121,7 +119,7 @@ def test_ventilation_mechanical(baseline_form: model_generator.FormData):
 
 
 def test_ventilation_airchanges(baseline_form: model_generator.FormData):
-    room = models.Room(75)
+    room = models.Room(75, inside_temp=models.PiecewiseConstant((0, 24), (293,)))
     airchange = models.AirChange(
         active=models.PeriodicInterval(period=120, duration=120),
         air_exch=3.,
@@ -153,7 +151,6 @@ def test_ventilation_window_hepa(baseline_form: model_generator.FormData):
     # Now build the equivalent ventilation instance directly, and compare.
     window = models.SlidingWindow(
         active=models.PeriodicInterval(period=120, duration=10, start=minutes_since_midnight(9 * 60)),
-        inside_temp=models.PiecewiseConstant((0, 24), (293,)),
         outside_temp=baseline_window.outside_temp,
         window_height=1.6, opening_length=0.6,
     )
diff --git a/cara/tests/conftest.py b/cara/tests/conftest.py
index 3cce3eb3..ef4bff1d 100644
--- a/cara/tests/conftest.py
+++ b/cara/tests/conftest.py
@@ -8,7 +8,7 @@ import pytest
 @pytest.fixture
 def baseline_concentration_model():
     model = models.ConcentrationModel(
-        room=models.Room(volume=75),
+        room=models.Room(volume=75, inside_temp=models.PiecewiseConstant((0., 24.), (293,))),
         ventilation=models.AirChange(
             active=models.SpecificInterval(((0., 24.), )),
             air_exch=30.,
@@ -55,7 +55,6 @@ def exposure_model_w_outside_temp_changes(baseline_exposure_model: models.Exposu
         baseline_exposure_model, {
             'concentration_model.ventilation': models.SlidingWindow(
                 active=models.PeriodicInterval(2.2 * 60, 1.8 * 60),
-                inside_temp=models.PiecewiseConstant((0., 24.), (293,)),
                 outside_temp=cara.data.GenevaTemperatures['Jan'],
                 window_height=1.6,
                 opening_length=0.6,
diff --git a/cara/tests/models/test_concentration_model.py b/cara/tests/models/test_concentration_model.py
index 432b4d80..3b1d9292 100644
--- a/cara/tests/models/test_concentration_model.py
+++ b/cara/tests/models/test_concentration_model.py
@@ -26,7 +26,7 @@ def test_concentration_model_vectorisation(override_params):
 
     always = models.PeriodicInterval(240, 240)  # TODO: This should be a thing on an interval.
     c_model = models.ConcentrationModel(
-        models.Room(defaults['volume'], defaults['humidity']),
+        models.Room(defaults['volume'], models.PiecewiseConstant((0., 24.), (293,)), defaults['humidity']),
         models.AirChange(always, defaults['air_change']),
         models.InfectedPopulation(
             number=1,
diff --git a/cara/tests/test_known_quantities.py b/cara/tests/test_known_quantities.py
index 78c4541f..ed775312 100644
--- a/cara/tests/test_known_quantities.py
+++ b/cara/tests/test_known_quantities.py
@@ -19,7 +19,6 @@ def test_no_mask_superspeading_emission_rate(baseline_concentration_model):
 def baseline_periodic_window():
     return models.SlidingWindow(
         active=models.PeriodicInterval(period=120, duration=15),
-        inside_temp=models.PiecewiseConstant((0., 24.), (293,)),
         outside_temp=models.PiecewiseConstant((0., 24.), (283,)),
         window_height=1.6, opening_length=0.6,
     )
@@ -27,7 +26,7 @@ def baseline_periodic_window():
 
 @pytest.fixture
 def baseline_room():
-    return models.Room(volume=75)
+    return models.Room(volume=75, inside_temp=models.PiecewiseConstant((0., 24.), (293,)))
 
 
 @pytest.fixture
@@ -131,11 +130,10 @@ def test_periodic_hepa(baseline_periodic_hepa, baseline_room):
     ],
 )
 def test_multiple_ventilation_HEPA_window(baseline_periodic_hepa, time, expected_value):
-    room = models.Room(volume=68.)
+    room = models.Room(volume=68., inside_temp=models.PiecewiseConstant((0., 24.),(293.15,)))
     tempOutside = models.PiecewiseConstant((0., 1., 2.5),(273.15, 283.15))
-    tempInside = models.PiecewiseConstant((0., 24.),(293.15,))
     window = models.SlidingWindow(active=models.SpecificInterval([(1 / 60, 24.)]),
-                inside_temp=tempInside,outside_temp=tempOutside,
+                outside_temp=tempOutside,
                 window_height=1.,opening_length=0.6)
     vent = models.MultipleVentilation([window, baseline_periodic_hepa])
     npt.assert_allclose(vent.air_exchange(room,time), expected_value, rtol=1e-5)
@@ -143,12 +141,12 @@ def test_multiple_ventilation_HEPA_window(baseline_periodic_hepa, time, expected
 
 def test_multiple_ventilation_HEPA_window_transitions(baseline_periodic_hepa):
     tempOutside = models.PiecewiseConstant((0., 1., 2.5),(273.15, 283.15))
-    tempInside = models.PiecewiseConstant((0., 24.),(293.15,))
+    room = models.Room(68, models.PiecewiseConstant((0., 24.),(293.15,)))
     window = models.SlidingWindow(active=models.SpecificInterval([(1 / 60, 24.)]),
-                inside_temp=tempInside,outside_temp=tempOutside,
+                outside_temp=tempOutside,
                 window_height=1.,opening_length=0.6)
     vent = models.MultipleVentilation([window, baseline_periodic_hepa])
-    assert set(vent.transition_times()) == set([0.0, 1/60, 0.25, 1.0, 2.0, 2.25,
+    assert set(vent.transition_times(room)) == set([0.0, 1/60, 0.25, 1.0, 2.0, 2.25,
             2.5, 4.0, 4.25, 6.0, 6.25, 8.0, 8.25, 10.0, 10.25, 12.0, 12.25,
             14.0, 14.25, 16.0, 16.25, 18.0, 18.25, 20.0, 20.25, 22.0, 22.25, 24.])
 
@@ -188,14 +186,13 @@ def test_multiple_ventilation_HEPA_HVAC_AirChange(volume, expected_value):
 )
 def test_windowopening(time, expected_value):
     tempOutside = models.PiecewiseConstant((0., 10., 24.),(273.15, 283.15))
-    tempInside = models.PiecewiseConstant((0., 24.), (293.15,))
     w = models.SlidingWindow(
         active=models.SpecificInterval([(0., 24.)]),
-        inside_temp=tempInside,outside_temp=tempOutside,
+        outside_temp=tempOutside,
         window_height=1., opening_length=0.6,
     )
     npt.assert_allclose(
-        w.air_exchange(models.Room(volume=68), time), expected_value, rtol=1e-5
+        w.air_exchange(models.Room(volume=68, inside_temp=models.PiecewiseConstant((0., 24.), (293.15, ))), time), expected_value, rtol=1e-5
     )
 
 
@@ -223,10 +220,9 @@ def build_hourly_dependent_model(
         outside_temp = temperatures[month]
 
     model = models.ConcentrationModel(
-        room=models.Room(volume=75),
+        room=models.Room(volume=75, inside_temp=models.PiecewiseConstant((0., 24.), (293, ))),
         ventilation=models.SlidingWindow(
             active=models.SpecificInterval(intervals_open),
-            inside_temp=models.PiecewiseConstant((0., 24.), (293, )),
             outside_temp=outside_temp,
             window_height=1.6, opening_length=0.6,
         ),
@@ -246,10 +242,9 @@ def build_hourly_dependent_model(
 
 def build_constant_temp_model(outside_temp, intervals_open=((7.5, 8.5),)):
     model = models.ConcentrationModel(
-        room=models.Room(volume=75),
+        room=models.Room(volume=75, inside_temp=models.PiecewiseConstant((0., 24.), (293,))),
         ventilation=models.SlidingWindow(
             active=models.SpecificInterval(intervals_open),
-            inside_temp=models.PiecewiseConstant((0., 24.), (293,)),
             outside_temp=models.PiecewiseConstant((0., 24.), (outside_temp,)),
             window_height=1.6, opening_length=0.6,
         ),
@@ -271,7 +266,6 @@ def build_hourly_dependent_model_multipleventilation(month, intervals_open=((7.5
     vent = models.MultipleVentilation((
         models.SlidingWindow(
             active=models.SpecificInterval(intervals_open),
-            inside_temp=models.PiecewiseConstant((0., 24.), (293,)),
             outside_temp=data.GenevaTemperatures[month],
             window_height=1.6, opening_length=0.6,
         ),
@@ -281,7 +275,7 @@ def build_hourly_dependent_model_multipleventilation(month, intervals_open=((7.5
         ),
     ))
     model = models.ConcentrationModel(
-        room=models.Room(volume=75),
+        room=models.Room(volume=75, inside_temp=models.PiecewiseConstant((0., 24.), (293,))),
         ventilation=vent,
         infected=models.EmittingPopulation(
             number=1,
diff --git a/cara/tests/test_monte_carlo.py b/cara/tests/test_monte_carlo.py
index a398e716..b948f4b9 100644
--- a/cara/tests/test_monte_carlo.py
+++ b/cara/tests/test_monte_carlo.py
@@ -40,10 +40,10 @@ def test_type_annotations():
 @pytest.fixture
 def baseline_mc_concentration_model() -> cara.monte_carlo.ConcentrationModel:
     mc_model = cara.monte_carlo.ConcentrationModel(
-        room=cara.monte_carlo.Room(volume=cara.monte_carlo.sampleable.Normal(75, 20)),
+        room=cara.monte_carlo.Room(volume=cara.monte_carlo.sampleable.Normal(75, 20), 
+                        inside_temp=cara.models.PiecewiseConstant((0., 24.), (293,))),
         ventilation=cara.monte_carlo.SlidingWindow(
             active=cara.models.PeriodicInterval(period=120, duration=120),
-            inside_temp=cara.models.PiecewiseConstant((0., 24.), (293,)),
             outside_temp=cara.models.PiecewiseConstant((0., 24.), (283,)),
             window_height=1.6, opening_length=0.6,
         ),
diff --git a/cara/tests/test_monte_carlo_full_models.py b/cara/tests/test_monte_carlo_full_models.py
index b97956b9..32fdd460 100644
--- a/cara/tests/test_monte_carlo_full_models.py
+++ b/cara/tests/test_monte_carlo_full_models.py
@@ -45,12 +45,11 @@ def shared_office_mc():
     Corresponds to the 1st line of Table 4 in https://doi.org/10.1101/2021.10.14.21264988
     """
     concentration_mc = mc.ConcentrationModel(
-        room=models.Room(volume=50, humidity=0.5),
+        room=models.Room(volume=50, inside_temp=models.PiecewiseConstant((0., 24.), (298,)), humidity=0.5),
         ventilation=models.MultipleVentilation(
             ventilations=(
                 models.SlidingWindow(
                     active=models.PeriodicInterval(period=120, duration=120),
-                    inside_temp=models.PiecewiseConstant((0., 24.), (298,)),
                     outside_temp=data.GenevaTemperatures['Jun'],
                     window_height=1.6,
                     opening_length=0.2,
@@ -88,12 +87,11 @@ def classroom_mc():
     Corresponds to the 2nd line of Table 4 in https://doi.org/10.1101/2021.10.14.21264988
     """
     concentration_mc = mc.ConcentrationModel(
-        room=models.Room(volume=160, humidity=0.3),
+        room=models.Room(volume=160, inside_temp=models.PiecewiseConstant((0., 24.), (293,)), humidity=0.3),
         ventilation=models.MultipleVentilation(
             ventilations=(
                 models.SlidingWindow(
                     active=models.PeriodicInterval(period=120, duration=120),
-                    inside_temp=models.PiecewiseConstant((0., 24.), (293,)),
                     outside_temp=TorontoTemperatures['Dec'],
                     window_height=1.6,
                     opening_length=0.2,
@@ -348,12 +346,11 @@ def test_report_models(mc_model, expected_pi, expected_new_cases,
 def test_small_shared_office_Geneva(mask_type, month, expected_pi,
                                     expected_dose, expected_ER):
     concentration_mc = mc.ConcentrationModel(
-        room=models.Room(volume=33, humidity=0.5),
+        room=models.Room(volume=33, inside_temp=models.PiecewiseConstant((0., 24.), (293,)), humidity=0.5),
         ventilation=models.MultipleVentilation(
             (
                 models.SlidingWindow(
                     active=models.SpecificInterval(((0., 24.),)),
-                    inside_temp=models.PiecewiseConstant((0., 24.), (293,)),
                     outside_temp=data.GenevaTemperatures[month],
                     window_height=1.5, opening_length=0.2,
                 ),
diff --git a/cara/tests/test_ventilation.py b/cara/tests/test_ventilation.py
index 134acf57..201da2c7 100644
--- a/cara/tests/test_ventilation.py
+++ b/cara/tests/test_ventilation.py
@@ -11,7 +11,6 @@ from cara import models
 def baseline_slidingwindow():
     return models.SlidingWindow(
             active=models.SpecificInterval(((0, 4), (5, 9))),
-            inside_temp=models.PiecewiseConstant((0, 24), (293,)),
             outside_temp=models.PiecewiseConstant((0, 24), (283,)),
             window_height=1.6, opening_length=0.6,
         )
@@ -21,14 +20,13 @@ def baseline_slidingwindow():
 def baseline_hingedwindow():
     return models.HingedWindow(
             active=models.SpecificInterval(((0, 4), (5, 9))),
-            inside_temp=models.PiecewiseConstant((0, 24), (293,)),
             outside_temp=models.PiecewiseConstant((0, 24), (283,)),
             window_height=1.6, opening_length=0.6, window_width=1.,
         )
 
 
 def test_number_of_windows(baseline_slidingwindow):
-    room = models.Room(75)
+    room = models.Room(volume=75, inside_temp=models.PiecewiseConstant((0, 24), (293,)))
     two_windows = dataclasses.replace(baseline_slidingwindow, number_of_windows=2)
 
     one_window_exchange = baseline_slidingwindow.air_exchange(room, 1)
@@ -63,9 +61,6 @@ def test_hinged_window(baseline_hingedwindow, window_width,
         {'outside_temp': models.PiecewiseConstant(
             (0, 2, 3), (np.array([20, 30, 28]), np.array([25, 30, 27]))
         )},
-        {'inside_temp': models.PiecewiseConstant(
-            (0, 20), (np.array([20, 30, 25]), )
-        )},
     ]
 )
 def test_hinged_window_vectorisation(override_params):
@@ -73,11 +68,10 @@ def test_hinged_window_vectorisation(override_params):
         'window_height': 0.15,
         'window_width': 0.15,
         'opening_length': 0.15,
-        'inside_temp': models.PiecewiseConstant((0, 2, 3), (20, 25)),
         'outside_temp': models.PiecewiseConstant((0, 2, 3), (10, 15)),
     }
     defaults.update(override_params)
-    room = models.Room(volume=75)
+    room = models.Room(volume=75, inside_temp=models.PiecewiseConstant((0, 2, 3), (20, 25)))
     t = 0.5
     window = models.HingedWindow(models.PeriodicInterval(60, 30), **defaults)
     if {'window_height', 'opening_length', 'window_width'}.intersection(override_params):