I need to find out the temperature change of air going through a chilled copper tube. The air will be traveling through 15 feet of tubing at a rate of 1 liter/second. The copper tube is chilled to 20 degrees F by a refrigeration unit and the air is 90 degrees F when it enters the tube. What will be the temperature of the air when it exits the tube?
How can I calculate this.
Solder (or clamp) tap valves at your desired temperature logging distances along the tubes length, removing samples of air to observe.
-0 ft (start reading): Air temp at 90 F
-7 1/2 ft (midpoint reading): ? F
-15 ft (end reading) : ? F
Important aspects that will likely vary the temperature in tube:
-Copper tube gauge thickness.
-Copper tube diameter ( I.D.** ?)
The air should move thru the tube fairly rapidly for a 1 cu. liter/second sized tubing
Calculate expected air density heat loss/ft. for known values, from charts on the internet (or from what others have recommended here).
Take temperature readings from sampling valves and see how close your predicted temperatures were.
Note: You may find a final drop in temperature as the air exits the tube, back into a larger space (quick expansion of gas causing expected temp drop).