Return air pathway sizing?

Reply

  #1  
Old 02-18-11, 05:14 PM
Member
Thread Starter
Join Date: Apr 2010
Location: United States
Posts: 11
Received 0 Votes on 0 Posts
Return air pathway sizing?

My home is about 1500 sq ft with 3 bedrooms. The doors are undercut only about a 1/2". I am going to install some return air pathways above the doors to improve the circulation. I am looking at the sound dampening ones made by Tamarack. I am just debating between the 12"x4" or 12"x6" rough opening sizes.

Each room is supplied with a single vent about 5.25"x9.5" opening. So the 12"x4" is about the same area but I was thinking since it has the baffle it might be better to go up to the 12"x6". Per Tamarack, the airflow @ 2.5 pascals is 48 for the 4" and 69 for the 6". Thanks for the help.
 
Sponsored Links
  #2  
Old 02-19-11, 08:22 AM
airman.1994's Avatar
Member
Join Date: Dec 2005
Location: VA
Posts: 5,767
Received 4 Votes on 4 Posts
Will have to do a heat load on the home to know what size u need
 
  #3  
Old 02-19-11, 01:48 PM
Member
Thread Starter
Join Date: Apr 2010
Location: United States
Posts: 11
Received 0 Votes on 0 Posts
Originally Posted by airman.1994 View Post
Will have to do a heat load on the home to know what size u need
Without sounding like an ass, I'm not really trying to get technical here. My home has been without the return vents since I bought it about 5 years ago so it isn't anything critical. Just want to increase the circulation. Think I will probably just go with the 12x6 and be done with it. Don't think it can hurt to go a little larger.
 
  #4  
Old 02-19-11, 05:18 PM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,482
Received 25 Votes on 19 Posts
A good rule of thumb is that return air ducts should be 1-1/4 to 1-1/2 times the area of the supply duct. This holds true from individual rooms to main supply and return ducts. It never hurts to go bigger on return ducts except maybe in the wallet.

Since you had nothing before any return air opening will help.
 
  #5  
Old 02-19-11, 07:57 PM
Member
Join Date: Jan 2011
Location: usa
Posts: 90
Received 0 Votes on 0 Posts
Originally Posted by ms0517 View Post
My home is about 1500 sq ft with 3 bedrooms. The doors are undercut only about a 1/2". I am going to install some return air pathways above the doors to improve the circulation. I am looking at the sound dampening ones made by Tamarack. I am just debating between the 12"x4" or 12"x6" rough opening sizes.

Each room is supplied with a single vent about 5.25"x9.5" opening. So the 12"x4" is about the same area but I was thinking since it has the baffle it might be better to go up to the 12"x6". Per Tamarack, the airflow @ 2.5 pascals is 48 for the 4" and 69 for the 6". Thanks for the help.
You probably only have a 6" pipe feeding this room which would not let more than 110 CFM on the average into the room, so your 12x 4 " would work fine.
You do have some under the door so your room can pressurize a little and let the right amount of air out of room. Paul
 
Reply

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


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: