Flex Duct Turns - HVAC - DIY Chatroom Home Improvement Forum


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 08-25-2010, 09:53 AM   #1
Member
 
Join Date: Aug 2010
Posts: 42
Rewards Points: 25
Default

flex duct turns


Should I have solid 90"S and 45's at the bends in my flex duct off the distribution box, and in the ceiling registers?

Advertisement

sjthompson is offline   Reply With Quote
Old 08-27-2010, 08:22 PM   #2
Member
 
Join Date: Aug 2009
Posts: 133
Rewards Points: 75
Default

flex duct turns


Although not absolutely necessary, I would recommend it. I have seen too many installations where the flex duct has nearly collapsed into itself on bends. A hard elbow is clearly better.

Advertisement

MI-Roger is offline   Reply With Quote
Old 08-27-2010, 09:40 PM   #3
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,546
Rewards Points: 4,730
Default

flex duct turns


Care must be taken not to kink the flex when making turns/bends.

If you really want to use hard pipe ells, nothing wrong with that.
beenthere is online now   Reply With Quote
Old 08-27-2010, 10:20 PM   #4
Wire Chewer
 
Red Squirrel's Avatar
 
Join Date: Jun 2009
Location: Ontario, Canada
Posts: 3,221
Rewards Points: 2,020
Default

flex duct turns


I would avoid flex where you can, in permanent setups. Think of how much more dust they will collect over time due to how they are made.
Red Squirrel is offline   Reply With Quote
Old 08-28-2010, 06:58 AM   #5
Member
 
Join Date: Mar 2010
Location: PENNSYLVANIA
Posts: 2,259
Rewards Points: 1,046
Default

flex duct turns


If you are making bends or connecting flex to register boots make sure you use a wide radius when making the turns and support them if needed.

No sharp bends.
COLDIRON is offline   Reply With Quote
Old 08-28-2010, 07:40 PM   #6
Member
 
Join Date: Aug 2010
Posts: 42
Rewards Points: 25
Default

flex duct turns


so how much diffrence does it make how tight the turn is into the register box? All mine are laying on the insulation on the attic floor and the just 90 down into the register box.
sjthompson is offline   Reply With Quote
Old 08-28-2010, 09:02 PM   #7
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,546
Rewards Points: 4,730
Default

flex duct turns


The tighter the 90, the more restricted the air flow is.

Hop in your car. Drive around the block. The first 2 turns, make them wide. Make the next 2 turns very tight. Feel the difference. It has the same effect on air. Throws more air to the one side, and slows it down.
beenthere is online now   Reply With Quote
Old 08-28-2010, 10:27 PM   #8
Registered User
 
Join Date: Mar 2009
Posts: 9,999
Rewards Points: 2,064
Default

flex duct turns


I would. You should be one size bigger on the straight runs: http://rockwallcontrols.com/Resident...ag=air-ducting

Pressure losses: http://www.mmmfg.com/pdfs/True_Cost_...x_10-27-06.pdf

http://www.thefreelibrary.com/Pressu.....-a0201591046

Gary

Advertisement

__________________
If any ads are present in my answer above, I do not condone/support/use the product or services listed, they are there against my permission.
Gary in WA is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
AC Flex Duct - Suspend above attic insulation or lay it on top? fritzycat1 HVAC 13 08-17-2011 11:19 PM
Metal duct or flex? smokey982 HVAC 6 08-06-2010 07:20 AM
flex duct termination issue LanterDan HVAC 2 02-12-2009 06:59 AM
Attaching Flex duct to register boot avshockey HVAC 15 12-03-2008 09:07 PM
Flex Duct Advice ssporty21228 HVAC 4 07-23-2008 09:28 PM




Top of Page | View New Posts