Hey Ed, can a duct be too big?

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In this edition of "Hey Ed," Ed discusses duct sizes.

Hey Ed, can a duct be too big? That is not something that can happen in my world. You cannot have a supply trunk or return trunk that is too big. You cannot have a branch run that is too big. You can have either of those that are too small because they exceed the velocity limit that you’ll find in manual D. But what can be too big is our supply outlet covering or what you might refer to as a register. If we do poor register selection, if the free area of that register is excessive, we will not get the proper throw and spread that will come out of a well designed air distribution system. And that’s the way I see it.

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

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Posted In: Hey Ed, Technical Tips