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

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

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-29-2011, 07:49 PM   #1
Newbie
 
Join Date: Oct 2010
Posts: 21
Rewards Points: 10
Default

Attaching additional trunk to side of plenum


I am in the process of adding an additional zone to my basement for heating. The best way to run the new trunk is by attaching it to the side of the plenum.

The attached picture "new trunk run" shows the space I have to work in. The max width I have is 12.75" and I am using 8x12 trunk size. I purchased a long way trunk elbow as shown in photo2. If I use a starter collar this puts the trunk elbow too far out. If I dont use the collar I am still too far out.

Is the proper way to make a tight turn to cut the plenum hole 7x11 and then cut 1" flaps and slide my trunk elbow in and screw it?

Thanks
Attached Thumbnails
Attaching additional trunk to side of plenum-new-trunk-run.jpg   Attaching additional trunk to side of plenum-photo2.jpg  

casnj is offline   Reply With Quote
Old 10-29-2011, 11:19 PM   #2
Member
 
Join Date: Oct 2011
Posts: 68
Rewards Points: 75
Default

Attaching additional trunk to side of plenum


Quote:
Originally Posted by casnj View Post
Is the proper way to make a tight turn to cut the plenum hole 7x11 and then cut 1" flaps and slide my trunk elbow in and screw it?

Thanks
I would cut a 8x12 hole and make a 1 inch (or whatever I needed to make it fit) flange fitting (bent outwards) on the trunk elbow. Then screw that to the plenum.

For difficult fittings, many times I just go to the gas furnace supply shop and give them a drawing, usually a few hours later I get a custom perfect fitting. They have all sorts of equipment.

bungalow_steve is offline   Reply With Quote
Old 10-30-2011, 08:34 AM   #3
fabrk8r
 
fabrk8r's Avatar
 
Join Date: Feb 2010
Location: Iowa
Posts: 849
Rewards Points: 500
Default

Attaching additional trunk to side of plenum


As bungalow steve suggested, make a drawing and take it to a sheet metal shop. They can make you a "short-throat" or "no-throat" ell with either an inside or outside tap for connecting to your existing trunk line. Have them put vanes in the ell for better air flow while they are at it.

You didn't mention in your original post how you determined that your air handler has sufficient blower capacity for adding a new run of duct.
__________________
"The physician can bury his mistakes, but the architect can only advise his clients to plant vines." -- Frank Lloyd Wright
fabrk8r is offline   Reply With Quote
Old 10-30-2011, 08:51 AM   #4
Newbie
 
Join Date: Oct 2010
Posts: 21
Rewards Points: 10
Default

Attaching additional trunk to side of plenum


Quote:
Originally Posted by fabrk8r View Post
As bungalow steve suggested, make a drawing and take it to a sheet metal shop. They can make you a "short-throat" or "no-throat" ell with either an inside or outside tap for connecting to your existing trunk line. Have them put vanes in the ell for better air flow while they are at it.

You didn't mention in your original post how you determined that your air handler has sufficient blower capacity for adding a new run of duct.
I had two different hvac companies come out and give me quotes. After deciding to go with one of them my job was really small and due to all the storms they have other jobs replacing peoples units($$). i decided to use the specs they have running 3 7" vents off the 8x12 and 1 7" off the plenum and a 7" return to do this job myself. I also can add in the zoning and pay about the same price they were going to charge me to just do the duct work.

Can I modify my existing fitting?

I have the technical aptitude and would love if someone would help me figure out how they figured this would work.

I know I have a american standard 9421 95% single stage furnace.
casnj is offline   Reply With Quote
Old 10-30-2011, 10:19 AM   #5
fabrk8r
 
fabrk8r's Avatar
 
Join Date: Feb 2010
Location: Iowa
Posts: 849
Rewards Points: 500
Default

Attaching additional trunk to side of plenum


Yes, you can just cut the throat down to the required 3/4" and remember to leave an extra 1" or so to turn out as a flange to attach to your plenum with crews and aluminum tape for sealing.
__________________
"The physician can bury his mistakes, but the architect can only advise his clients to plant vines." -- Frank Lloyd Wright
fabrk8r is offline   Reply With Quote
Reply


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Removing Extended Plenum Calm_Blue_Ocean HVAC 15 01-07-2008 05:22 PM
coming off the plenum to trunk lines qnzkrew HVAC 3 01-01-2008 09:27 PM
Side By side refrigerator Susie Q Appliances 6 08-31-2007 03:26 PM
Attaching Roof to side of home joe3534 Roofing/Siding 1 04-29-2007 09:54 PM
Plenum Design winkydink HVAC 1 11-22-2006 10:28 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.