Ambient temperature

From Overclocking Wiki

Ambient temperature is the temperature of the fluid surrounding a particular object.

Because heat is transferred by conductance, the ambient temperature of the air or liquid around an object who's temperature is being measured is important in understanding the changes in temperature of the object.

The ambient temperature of a PC case is usually the temperature of the air in the room where the PC is being used. If the PC was moved outside, the ambient temperature would be the temperature of the air locally surrounding the machine.

Something that is sub-ambient is colder than the air around it. Air- or water-based cooling devices can't produce sub-ambient temperatures becasue they can't overcome the thermal energy in the head they use for cooling. Extreme cooling devices, such as phase change cooling systems, are required to reach sub-ambient temperatures.

Warning

Anything sub-ambient will cause condensation of any available humidity. A glass of ice water in a warmer room is a convenient example: the water on the outside of the glass condensed from the air onto the colder surface of the glass. Also, dew is formed in this identical manner when the air temperature rises quickly leaving the grass colder than the air briefly.

Benefit

If you can lower the ambient temperatures (room temps) you will lower your case temps and the temps of all components inside the case. If your overclock requires cooler temps than you can get by swapping HSF's and case cooling lowering the ambient (room) temperature will help.