Go Back  DoItYourself.com Community Forums > Interior Improvement Center > Basements, Attics and Crawl Spaces
Reload this Page >

Adding duct work to existing Central Air in Attic

Adding duct work to existing Central Air in Attic


Old 08-09-08, 12:17 PM
Thread Starter
Join Date: Aug 2008
Posts: 1
Received 0 Votes on 0 Posts
Adding duct work to existing Central Air in Attic

I am thinking of finishing my attic. I have central air downstairs, the duct work runs under the old hardwood floors in the attic. what is the process of venting up through the floors to the upstairs. What materials are needed? Other that making sure my unit has the tonage to keep everything cool, is there anything else i need to know.
Sponsored Links
Old 08-09-08, 12:31 PM
Join Date: Mar 2006
Location: USA
Posts: 94
Received 0 Votes on 0 Posts
You may get replies that say only a trained hvac specialist can perform the necessary load calculations to adequately address your situation. Which is probably true.

But if you want to try it yourself, you'll need to create a supply feed into the room. Using flex duct is the easiest, otherwise you'd have to put together sections of sheet metal that you buy at HD. You'll also need to plan to run a return line too.

It will be hard to adequately circulate the air in your attic as they are notorious for getting hot - and your registers will be in the floor. A ceiling fan would help.

I'd suggest you get an on-site opinion from a pro.
Old 08-09-08, 06:54 PM
airman.1994's Avatar
Join Date: Dec 2005
Location: VA
Posts: 5,795
Received 8 Votes on 8 Posts
I agree with walkman! Your unit will not be sized for the extra load. Your duct will not be sized for the extra load. Id look into a ductless split.
Old 08-12-08, 07:45 PM
Shandy's Avatar
Join Date: Jul 2008
Location: Hendersonville, NC
Posts: 35
Received 0 Votes on 0 Posts
Zone It

You could do it yourself with the right amount of research. I installed an zone system in my house and I love it. Basically you add a supply to the trunk of your system with an electric damper. A second electric damper will be added to your main run for the rest of the house. A thermostat will be placed in the finished attic to control its needs. Some homes and businesses have thermostats for each room and are controlled by electric dampers.

I am not a pro by any means but worked a few summers while in college at a HVAC place, learned a little about the zone systems. It was way cheaper than adding a second system.

Good luck,
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
Ask a Question
Question Title:
Your question will be posted in: