Colder Water, Cooler Air: The Impact on Cooling Efficiency in Air Units

AI Thread Summary
Colder water entering an air unit enhances cooling efficiency by increasing the temperature difference between the water and the air, known as the approach temperature. While bringing in water at 2C can lead to cooler air, the actual temperature drop may not reach the expected levels due to increased thermal resistance. The delta T, or temperature difference, can improve from 5C to 6C, resulting in a potential 8C return water temperature. Calculating the total effect in Watts requires specific formulas that account for the heat transfer rates and temperature differences. Overall, colder water does improve cooling performance, but the extent of the improvement is influenced by thermal dynamics.
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If a cooling element in an air unit was designed for water temperatures of 7C in and 12C out, how much "better" will it become if it receives water at 2C ? Let's say the return is then 7C, will the effect then be the same since the delta T is the same as it was with 7/12 ? It just seems so logical to me that bringing colder water in will result in cooler air...
 
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Correct, although you won't get quite 5C colder air, the greater water-air temperature difference will cause more heat to flow but it will also increase the effects of anny thermal resistance.
 
This is called improving your "approach temperature". A bigger approach temperature will improve heat transfer and therefore you will pull more energy out of the air. So the delta T will go from, say, 5 C to 6C and you'll get perhaps 8 C return water. Of course, the approach temperature of the chiller that is making that water gets worse when you do that...
 
Thx guys, just one more thing; if this will indeed make the air cooler, how can I calculate the total effect in Watts?
 

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