> As a result the most efficient way to cool a server is to put a water filled heat exchanger in front of it and let the computer's fans draw air through that

> As a result the most efficient way to cool a server is to put a water filled heat exchanger in front of it and let the computer's fans draw air through that into the chassis. What standard are you using for "efficient"? Thermo-electric coolers are neat, but the last thing they are whatsoever is efficient from a power-usage stand point. If you're doing chilled water cooling, the only real option to consider is a mechanical heat pump (e.g. the ones in a refrigerator), but even that is silly. Hardware doesn't mind being somewhat warm, and using ambient air for cooling is far more efficient then either. There's a reason thermoelectric refrigerators aren't really a thing. Peltiers are horrible. Mechanical heat pumps easily achieve twice the efficiency or more.