Would like to share the outcome of the installation, I used a double sided bubble radiant barrier and then 2 months ago installed a solar fan

Before:-
Plaster Ceiling :- 38.4c, Roof tiles:- 55C, air cond power :- 900-1000w.

With this I estimate attic temperature to be around 40-44c, going up to the room is like  a sauna..




After:- Radiant Barrier only
Plaster Ceiling :- 32-33c, Roof tiles:- 36-38C, air cond power :- 400-450W.
A radiant barrier really works, a must have. Made a huge difference in room temperature.
At the same time I started putting temperature sensor at my attic, external (outside my window) and my room to log the temperature.
I notice around 2c difference between external temperature and the attic temperature.


After:- Radiant Barrier + solar fan
Installed a solar fan so it would turn on roughly 8am to maybe 6- 6:30pm. Made a small difference, temperature now within 0.5c compared to external temperature.
Also integrated all in home assistant , to log the temperature and air cond power. Small savings in air cond power (maybe around 50w on average?)

Look at post 7 for example

Look at blue arrow
staple radiant barrier to the blue arrow wood.
The thickness of the wood act as air gap.