1) Why we prefer that duct shapes should be square?
2) Whats the difference between circular shaped ducts and square shaped ducts , i mean where we will prefer circular shape and where we will prefer square shape ducts?
square shapes fit over ceilings and match up with square equipment better. they are easier to hook different sizes together. round would be more efficient in every way if it would fit.
Rectangular shaped ducts have a way of being easy to layout and install as opposed to round or oval. As noted, above ceiling is a consideration on any project, especially larger commercial jobs requiring lots of airflow. Every trade knows that there will be a duct somewhere that they have to miss with their pipe, wire whatever.
In commercial real estate, area of the occupied space is treated like gold, so ceiling heights, mechanical room sizes etc all come in to play in calculations of rent, utilities etc in terms of price per square foot.
Round duct is a pain in the butt if it gets squooshed a bit at the shop, on the truck, or hanging around the job site before it gets installed. Rectangular duct is stronger.
I ditto everthing except
Double wall spiral duct is pretty stout also.
Rectangular duct is stronger.
If I would of killed my wife when I first met her, I'd be out of jail by now!
I never installed double wall spiral, so I'm ignorant about it...
Round duct is also easier to take apart to clean or replace than rectangular would be, such as from an oil burner, especially for a typical home owner to do themself.
Nice Striper Duece! Is that picture recent?
Square duct has less resistance to airflow, is cheaper to make, and more economical to install.
"Christ is the Son of God Who died for the redemption of sinners and was resurrected after three days. This is the greatest truth in the universe. I die because of my belief in Christ."
Square is easier to custom fab in the shop.
Rectangular is low profile
The shape matches the air handlers
Both look more expensive than round
Round provides the least friction loss
You can fit more on the truck
It's generic, and you can buy it in bulk
It is available to any hack without a shop and therefore sometimes has a bad name.
I strongly disagree with everything said here...lol.
Originally Posted by ACFIXR
Spiral is by far easier to install than sqaure as well as having less resistance to airflow when using full radius elbows. It can also be installed at least 2x faster. And with the use of gasketed fittings, it will also seal tighter than most square duct. Our shop can whip out the spiral like you wouldn't believe. Square duct is used because of the endless possiblities of changing dimensions while maintaining a required area, especially with space limitations. Round is somewhat limited in that area.
Chicago is an indian word for stinky!!!!!!
You got that friggen right!
Originally Posted by Lash
It takes courage to grow up and turn out to be who you really are.
- E.E. Cummings
Our shop can do spiral faster than any cheeser shop
Originally Posted by Lash
Also take into account the aspect ratio which is ideally less than 3:1 or 24 x 8, w/h=A.R.