Hey Ed, What Is the Most Important Thing to Follow in Manual D?

In this edition of "Hey Ed," Ed talks about the most important thing to follow in Manual D.

Hey Ed, what is the most important thing to follow in Manual D? The most important thing to follow in Manual D from my perspective, and if you want to argue about this, EDJ@acca.org is the easiest way to get ahold of me. The most important thing from my perspective, because it’s the thing that is neglected the most, is dampers. Manual D is built on the premise that we’re going to put air through ducting. As long as we don’t exceed the velocity limits, we don’t care how fast that air is moving. There’s no such thing as velocity that’s too low. What we care about is getting the proper volume through the branch runs, and I don’t care if it’s going through a big duct or a little duct on the little duct side. Maybe I care because I don’t want to exceed my velocity limits. It gets too big, and I have more surface area, and maybe it’s in an aggressive environment. But at the end of the day, I care about getting the proper volume through the branch runs so we get the predictable throw and spread out of the register, as long as we do a proper design. There are other things that are neglected at times, but dampers, in my opinion, are the most neglected part of duct design. And that’s the way I see it.