I would like to direct your attention to this link:
http://www.physics4kids.com/files/thermo_laws.html

Yes it's true. Heat does rise. Quite possibly the reason why basements are cold and dank.... which is also a problem. Basements are usually wet. All those pipes sweating and not alot of ventilation can play hell on any sort of electrical equipment, especially high end overclocked computers such as used for mining operations. Which also brings up why the rest of your post is garbage too, opening a window will do the same thing and the wild swings in humidity/temperature that happen frequently in more than half the world, are also not very good for sensitive high end electrical equipment.

There is a reason why one of the most expensive things about professional large scale data-centers is the money spent on Climate Control. Your mining machines are no different.