Water is often used for cooling high power equipment, and this week's quiz is designed to give you an idea of how much water it takes to cool a device like a large ham amplifier. The three possible answers I've listed below are different enough that you can probably guess the right one without having to do any calculations, if you have some experience with water cooling or a good intuition on the subject. If not, a quick web search will yield the simple equation for finding the answer.

Let's say you want to use water to remove 5000 watts of heat from something like a dummy load or 4CW5000 tube running at its maximum anode dissipation. The water input temperature is 20C and the output temperature is to be a warm, but not boiling hot, 50C (water temp rise = 30C). How much water flow do you need?

2.4 liters/minute (0.63 gallons/minute)

12 liters/minute (3.2 gallons/minute)

45 liters/minute (12 gallons/minute)

Answer:

2.4 liters/minute (0.63 gallons/minute)

Water cooling is very efficient!