According to one embodiment of the invention, a method is provided for
cooling heat-generating structure disposed in an environment having an
ambient pressure. The heat-generating structure includes electronics. The
method includes providing a coolant, reducing a pressure of the coolant
to a subambient pressure at which the coolant has a boiling temperature
less than a temperature of the heat-generating structure, and bringing
the heat-generating structure and the coolant at the subambient pressure
into contact with one another, so that the coolant boils and vaporizes to
thereby absorb heat from the heat-generating structure. In a more
particular embodiment the coolant is either pure water or pure methanol
with an electrical resistivity level of greater than one million Ohms-cm.
Further, in another particular embodiment the method includes filtering
the coolant to maintain its purity above a particular level.