Thursday, April 08, 2010

Dept. of Subtle - Air Terminals

Revit calls the device that HVAC systems use to pass air through a ceiling or wall and connect to duct work and plenums - air terminals. They are much more commonly referred to as diffusers. Turns out that an air terminal is the sharp end of the stick in lightning protection systems. One engineer I met recently was a bit annoyed by the inappropriate use of the term.

Language is hard!!

According to Wikipedia:
Individual lightning rods are sometimes called finials, air terminals or strike termination devices.

Also according to Wikipedia:
Air terminals are the supply air outlets and return or exhaust air inlets. For supply, diffusers are most common, but grilles, and for very small HVAC systems such as in residences, registers are also used widely. Return or exhaust grilles are used primarily for appearance reasons, but some also incorporate an air filter and are known as filter returns.

So there you have it, both are correct! Rest easy knowing that if you call your diffusers air terminals or your air terminals diffusers you are good to go! Unless you do lightning protection too? Confused?

3 comments:

Craig Thomas said...

Language ... one of my favorite topics. Because it often gets in the way of communication and ultimately understanding. Which is why, I think, the more I learn, the less I know ... but I digress.

So where, in the Revit world, should the lightning protection person put their "strike termination devices"?

I use this term because I am more familiar with "finials" being used to describe a decorative ornament on the ends of curtain rods or applied to chairs and furniture.

Haha. Language ... ya gotta love it.

Brian Payne said...

Steve, you had me confused there for a bit. I had to reread the third sentance a couple of times to realize that you were talking about lightNing rather than lighting. Having done a bit of work in gymnasiums...a lighting protection system sounded reasonable enogh, but what that had to do with air terminals was beyond me!

brianl said...

And it doesn't help that HVAC also has Terminal Units or Boxes.