Do not attach too much importance to this.
What if you are in a place like Norway where the sun does not set for two months then which direction should you face?
'Daivam sarvato mukha', God is everywhere, so you can sit anywhere, in any direction for your prayers and meditation.
These scientific explanations are good primarily for tropical countries. If the sages had taken into account the arctic regions, they might have recommended that prayers and meditation to be done facing South.
Similarly, Vastu Shastra which is suitable for India may not be appropriate for Russia.
We need to make some corrections in these recommendations based on the region of the earth where it is being applied.
In India it is recommended that the main entrance to the house should not face south, because in those days the city was planned in such a way that cremation grounds were to the south of the city and breeze blowing from that direction would enter the house through the doors and windows facing south. So Vastu was formulated accordingly.
But if you go to Russia and the Scandinavian countries, there the sun is more intense in the south, and pleasant breeze blows from the south, so it is okay to have the main entrance facing south. If you keep the door which is facing south open, you will get plenty of sun all year round.
Therefore, applying Vastu Shastra blindly without making corrections is not right. Many people do not know this. They don't go into the depths of this knowledge. They are 'lakeer ke fakeer' - they follow without questioning what is written.