The trunk line is a line of ductwork that serves as the central distribution source for your ductwork system. It is attached directly to the plenum and runs through the entire length of your house. … Note: The trunk line is typically attached six inches from the top of the plenum.

What is a trunk in HVAC?

So, it comes as no surprise that the trunk line of a heating system is the large duct leading out of the furnace that delivers the massive amounts of air it takes to heat or cool a house. … As trunk lines move further away from the furnace, they often taper in size for greater efficiency.

What is a duct on a car?

Ducts are there to capture air from, ideally, a clean, high energy source and conduct it to the place it needs to be used (usually for cooling of some sort, or for “feeding” an engine). Flow in a diffusing duct – shows a simplified boundary layer (blue slow moving, red faster, clear fast)