Hey Ed, What Is the Difference Between Duct Design and Manual D?

In this edition of "Hey Ed," Ed talks about the difference between duct design and Manual D.

Hey Ed, what is the difference between Duct Design and Manual D? - The difference between Duct Design and Manual D is quite simple. Manual D has a normative section where we follow the rules that are in the book. Duct Design comes in many forms and what I see far too often is people will pick and choose what they want at a Manual D but not follow it in its entirety and then it turns into what I call Duct Design. If I follow Manual D, I get predictable results. If I follow a Duct Design that I don’t know where it comes from, I simply don’t know what those results are gonna be. I want predictable results and that’s the way I see it.