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Hey Ed, What’s the Deal With Big Hoses?

In this edition of "Hey Ed," Ed discusses what the deal is with big hoses.

Hey Ed, what's the deal with big hoses? You’re making me blush, but I can answer that question. When we're talking about using a larger diameter hose for evacuation, it’s another one of those things in our industry that comes back to math. If you look at pressure and flow, if you double the pressure on the same size pipe, you’ll double the flow. The same thing works out, and I think I might do that again 'cause I didn't like the way that I said that. When we looked at anything that has to do with flow-through pipe, the math for pressure versus vacuum is not the equivalent. If you double the sizes of the pipe and maintain pressure, you double the flow. If we're doing a vacuum, if you double the size of the pipe, you increase the flow by a factor of 4. Often technicians will evacuate a system with a charging manifold and listen to what that’s called - a charging manifold - not an evacuation manifold. Quarter-inch hoses are typically what’s used. It’s commonplace now to go up to as much as a half-inch hose, so we've quadrupled the size of the pipe. If we are looking at an increase of a factor of four, I'm gonna show up my math skills here, 4*4 is 16, we can reduce the amount of time it takes to evacuate the system 16 times so you can see where there's a big advantage to having a big hose when it comes to evacuating the system. And that's the way I see it.

In this edition of “Hey Ed”, Ed discusses what the deal is with big hoses

Ed Janowiak

Ed Janowiak is the Manager of HVAC Design Education at ACCA.

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Posted In: Hey Ed, Technical Tips

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