Thank you this was helpful. I did this, and also compared with a hand-calculation comparing only strata heat and air free cooling.
The scenarios are a) leave as is, b) completely open partial blockages to let more air through c) completely block partial blockages.
The two methods show improvement in scenarios (b) and (c) but differ in which is the preferred of the two. This may be because my hand calculation ignores moisture.
Providing results below for interest:
Sigma Heat (caculated as per instruction above); option (b) is preferred.
Case
Sigma heat, kJ/kg
a) Initial state
24.4
b) Partial blockages cleared entirely
23.3
c) Blockages hermetically sealed
24.3
Simplistic calculation of change in air and strata heat flow; option (c) is preferred.
Case
Change in Airflow m3/s
Delta cooling power of incoming air, kW[1]
Delta rate of heat flow from strata heat, kW
Delta rate of heat flow, net of air and strata, kW
a) Initial state
-
-
-
-
b) Partial blockages cleared entirely
+17
-340
+210
-130
c) Blockages hermetically sealed
-11
+225
-508
-283
[1] Assuming air at 20°C, threshold at 26°C DB),