DIY Home Improvement, Remodeling & Repair Forum > Appliances > HVAC > Duct flow problems




Reply
 
Thread Tools Search this Thread Display Modes
Old 11-29-2008, 11:43 AM  
ElvisCat59
Junior Member
 
Join Date: Nov 2008
Posts: 1
Default Duct flow problems

Our house is a 1000 sq foot ranch with a 500 ft Family Room Addition built on a slab.
to get supply heat and a/c into the room, I had to run an 8"supply duct in my crawl space upt to my attic, a distance of 25 feet.
Off of that I have 4- 6x10" vents on the perimeter walls that are fed by a 6" supply.
Problem #1- My first two vents that are fed by 2- 6" 90Degree elbows get very little flow. they are not the end of the run but in the middle.
Problem #2- I have trouble keeping the room warm even with the new windows and the attic insulated. Average Temperature inside is 62 degrees when outside air temp is 20 degrees.

I tried a duct booster and it doesn't solve the problem doesn't help at all.

Trane Furnace XE80, 90,000 BTU Downflow.


__________________
ElvisCat59 is offline  
 
Reply With Quote Quick reply to this message
Old 11-29-2008, 05:25 PM  
glennjanie
Senior Member
 
Join Date: Mar 2006
Posts: 2,990
Liked 2 Times on 2 Posts

Send a message via AIM to glennjanie
Default

Welcome ElvisCat:
I see you have a downflow furnace. Is the new room at a lower elevation? Are you using metal pipe? Flex duct wears the air out and drags it down. Each elbow adds 10' to the effective length of the duct. Are the 6" vents taken off with tees or just cut into the 8" pipe? The tee, take off will encourage more air to divert into the 6" pipe.
If the new room is at a lower elevation; it would be best to run the new duct under the floor of the house and come out in the wall of the new room, even if it has to go through concrete block.
It would also help to have 2 8" pipes to feed the 4 6" ones. An 8" is just not enough for more than 2 6" pipes.
Please let us know how you come out with it and we love pictures too.
Glenn



__________________
glennjanie is offline  
 
Reply With Quote Quick reply to this message
Old 12-24-2008, 05:37 AM  
ductworksystem
Junior Member
 
Join Date: Dec 2008
Posts: 1
Default

provides the capability to easily model onedimensional fluid flow. In this unit, you'll learnhow to: Represent duct flow networks with curves, Define beam sections and beam, elements to model fluid flow, Define duct flow boundary conditions.
thanks ..ductworks.net

__________________
ductworksystem is offline  
 
Reply With Quote Quick reply to this message
Old 12-25-2008, 10:27 AM  
Daryl in Nanoose
Senior Member
 
Daryl in Nanoose's Avatar
 
Join Date: Feb 2006
Location: Nanoose Bay, BC
Posts: 762
Liked 3 Times on 3 Posts
Likes Given: 5

Default

Glenn has hit the nail on the nose.
I would of went with at least a 10" main with 5" take offs and 4x10 vents.

__________________

[url]http://edhome.shawwebspace.ca/[/url]

Daryl in Nanoose is offline  
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


Similar Threads
Thread Thread Starter DIY Home Repair Forum Replies Last Post
duct insulation kc2651 General Home Improvement Discussion 7 01-10-2009 04:20 PM
Thermostat line running through duct intake ITParalegal HVAC 4 09-10-2007 12:28 PM
Ductwork txgrl74 HVAC 7 09-10-2007 12:06 PM
Remove Fungus from Main Beam of House And Insulate Duct spillinatech HVAC 2 02-27-2007 12:35 PM
Enough room for hanging duct work Mudball HVAC 2 08-16-2006 07:01 PM

Newest Threads

LATEST SPONSOR DEALS