[Dog Gone]

Dealing with low basement height clearances is a common problem for many remodelers. Aside from the occasional beams, HVAC supplies and returns are often the biggest obstical. Traditionally, we've minimized the ductwork's intrusion by using shallower and wider ducts and creating ceiling soffits.

What would be the problem with constructing the Supply line so that is has a short down-vent immediately leaving the furnace and running supply along the FLOOR hiding ducts under window seats, etc.

Seems like it would create some ininital resistance making blower work harder and consuming more power - but if sealed well wouldn't this function normally?

 

[flashheatingand]

The problem is that the air will gyrate too close to the furnace. As a result, it is highly possible that the furnace will over heat during the winter, and possibly the coil will freeze during the summer. I like the air to shoot straight for at least 2 feet before going into a 90. However, field conditions don't always allow this. The closer the off-set from the furnace, the greater the risk of air-flow problems

Go Hawks!!

 

[beenthere]

You would have to make the duct bigger to allow for the extra turns, and the longer length.
You also would add a large cost to the install, in those applications that the joist are panned for returns. Since now they would have to be hard piped.

The real easy solutions are.
A: Builders/architects design the homes to have the duct work run in the conditioned area of the home..
B: Make the basement 9' high.