HVAC Duct In Garage Condensation - HVAC - DIY Chatroom Home Improvement Forum
Advertisement


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

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

Like Tree5Likes
  • 1 Post By Nealtw
  • 1 Post By ryansdiydad
  • 1 Post By Yodaman
  • 1 Post By ryansdiydad
  • 1 Post By ss427
Reply
 
Thread Tools
Display Modes
Old 03-09-2019, 09:07 AM   #1
Newbie
 
Join Date: Jun 2017
Posts: 6
Rewards Points: 12
Default

HVAC Duct in Garage Condensation


Hello, This HVAC duct is surface mounted against the ceiling in my garage. If I need to have the outside doors open for any length of time during the summer months a lot of condensation forms on the duct. I am thinking of gluing rigid foam insulation material as pictured directly to the duct to encase the duct to seal it off from the garage air. I have read where the foam panels are not meant to be left exposed but the "firewall" is still the ceiling material which is undisturbed. Is there some better way correcting the problem? Thank you.
Attached Thumbnails
HVAC Duct in Garage Condensation-img_4135.jpg   HVAC Duct in Garage Condensation-img_4132.jpg  
ss427 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 03-09-2019, 09:12 AM   #2
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: Washington DC Metro Area (VA, MD, DC)
Posts: 19,808
Rewards Points: 3,288
Blog Entries: 32
Default

Re: HVAC Duct in Garage Condensation


Is there a height issue there? Otherwise, I would prefer to see it covered in foam and drywall.


Be sure to seal all the seams as it should have ZERO communication with what is in the garage.
Windows on Wash is online now   Reply With Quote
The Following User Says Thank You to Windows on Wash For This Useful Post:
ss427 (03-09-2019)
Sponsored Links
Advertisement
 
Old 03-09-2019, 09:29 AM   #3
Newbie
 
Join Date: Jun 2017
Posts: 6
Rewards Points: 12
Default

Re: HVAC Duct in Garage Condensation


Well it is pretty low in there, about 78 inches between the floor and the bottom of the duct. It is toward the corner where you normally don't walk though.
ss427 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 03-09-2019, 09:33 AM   #4
retired framer
 
Join Date: Jun 2017
Location: Fraser Valley BC Canada
Posts: 22,986
Rewards Points: 13,860
Default

Re: HVAC Duct in Garage Condensation


Google fire safe duct insulation.

Foam need to be covered with drywall and that should have been boxed insulated and drywalled but there are products you can use there. It should be fire rated to slow a garage fire from getting to the house.
Windows on Wash likes this.
__________________
Do not use flat bottom gables with scissor trusses.
Nealtw is offline   Reply With Quote
The Following User Says Thank You to Nealtw For This Useful Post:
ss427 (03-09-2019)
Old 03-09-2019, 09:42 AM   #5
Newbie
 
Join Date: Jun 2017
Posts: 6
Rewards Points: 12
Default

Re: HVAC Duct in Garage Condensation


OK, I am convinced. I'll box it in. What would you use as the insulation material? Is regular 1/2 drywall ok for the enclosure or does it need to be something else?
ss427 is offline   Reply With Quote
Old 03-09-2019, 10:58 AM   #6
Member
 
Join Date: Nov 2014
Location: Canada
Posts: 9,119
Rewards Points: 990
Default

Re: HVAC Duct in Garage Condensation


There's duct insulation that can be used if you don't want a major foam/drywall job.

may be hard to install though:

__________________
WARNING: I am not in the business of any trade or topic I give advise on. Follow the advice I post at your own risk. I only have previous diy experience plus good knowledge of theory.
user_12345a is online now   Reply With Quote
The Following User Says Thank You to user_12345a For This Useful Post:
ss427 (03-09-2019)
Old 03-09-2019, 11:36 AM   #7
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: Washington DC Metro Area (VA, MD, DC)
Posts: 19,808
Rewards Points: 3,288
Blog Entries: 32
Default

Re: HVAC Duct in Garage Condensation


You need to insulate it in conjunction with boxing it in.



If you detail out the seams and seal the ductwork, 1/2-1" will probably be sufficient.
Windows on Wash is online now   Reply With Quote
The Following User Says Thank You to Windows on Wash For This Useful Post:
ss427 (03-09-2019)
Old 03-09-2019, 11:48 AM   #8
retired framer
 
Join Date: Jun 2017
Location: Fraser Valley BC Canada
Posts: 22,986
Rewards Points: 13,860
Default

Re: HVAC Duct in Garage Condensation


Quote:
Originally Posted by ss427 View Post
OK, I am convinced. I'll box it in. What would you use as the insulation material? Is regular 1/2 drywall ok for the enclosure or does it need to be something else?
If you are boxing it you foam will be fine just seal that to the ceiling and the build the two sides just low enough the the bottom drywall clears the insulation. 1/2" drywall is fine. For less than 2 feet you don't need the 2x4s on the bottom but finding a joist running in the same direction can get tricky.

__________________
Do not use flat bottom gables with scissor trusses.
Nealtw is offline   Reply With Quote
The Following User Says Thank You to Nealtw For This Useful Post:
ss427 (03-09-2019)
Old 03-09-2019, 11:58 AM   #9
Member
 
Join Date: Aug 2015
Posts: 753
Rewards Points: 1,502
Default

Re: HVAC Duct in Garage Condensation


Thermax foam board can be left exposed. But boxing it in just looks better.

https://www.dupont.com/products/THER...nsulation.html
Nealtw likes this.
ryansdiydad is offline   Reply With Quote
The Following User Says Thank You to ryansdiydad For This Useful Post:
ss427 (03-09-2019)
Old 03-09-2019, 12:22 PM   #10
retired framer
 
Join Date: Jun 2017
Location: Fraser Valley BC Canada
Posts: 22,986
Rewards Points: 13,860
Default

Re: HVAC Duct in Garage Condensation


It looks like we can see some dirt on the wall below the right hand corner, that is bad news anyway. You can not allow an air leak from the garage in to the house.

Auto off gasses are a killer.
__________________
Do not use flat bottom gables with scissor trusses.
Nealtw is offline   Reply With Quote
The Following User Says Thank You to Nealtw For This Useful Post:
ss427 (03-09-2019)
Old 03-09-2019, 12:27 PM   #11
Property Mgt/Maint
 
Join Date: Mar 2015
Location: Upstate NY
Posts: 5,365
Rewards Points: 6,226
Default

Re: HVAC Duct in Garage Condensation


Quote:
Originally Posted by ryansdiydad View Post
Thermax foam board can be left exposed. But boxing it in just looks better.

https://www.dupont.com/products/THER...nsulation.html

A few years ago, I was looking for a fire rated foam board. No one stocked it locally. I finally got a quote from 84 lumber, it was 2 times the coast of regular and I had to buy in bundle quantities. It really wasn't practical for my application.

Side note: there was some question earlier about there already being a fire wall in place implying that maybe the foam didn't need to be covered.

The covering of the foam is to prevent the rapid toxic off gassing in case of a fire, and has nothing to do with the fire rated wall.
Nealtw likes this.
__________________
[political signature removed]

Last edited by Yodaman; 03-09-2019 at 12:30 PM.
Yodaman is offline   Reply With Quote
The Following User Says Thank You to Yodaman For This Useful Post:
ss427 (03-09-2019)
Old 03-09-2019, 02:07 PM   #12
Member
 
Join Date: Aug 2015
Posts: 753
Rewards Points: 1,502
Default

Re: HVAC Duct in Garage Condensation


Quote:
Originally Posted by Yodaman View Post
A few years ago, I was looking for a fire rated foam board. No one stocked it locally. I finally got a quote from 84 lumber, it was 2 times the coast of regular and I had to buy in bundle quantities. It really wasn't practical for my application..
Yeah. I was gong to mention that but got lazy. The big box guys won't even know what it is and when you track down someone that does they will tell you that you have to order a truckload. Do not bother with either.

You might be lucky if you have a good local lumber yard. My local lumber yard knew exactly what it was and said they can get any quantity with no minimum. Haven't ordered any yet to see if it's true.
Yodaman likes this.
ryansdiydad is offline   Reply With Quote
The Following User Says Thank You to ryansdiydad For This Useful Post:
ss427 (03-09-2019)
Old 03-09-2019, 05:52 PM   #13
Newbie
 
Join Date: Jun 2017
Posts: 6
Rewards Points: 12
Default

Re: HVAC Duct in Garage Condensation


You folks are awesome. Thank you for the helpful replys.
Nealtw likes this.
ss427 is offline   Reply With Quote
Sponsored Links
Advertisement
 
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
garage roof condensation excessive Martina10 Building & Construction 17 03-06-2015 09:58 AM
Replacing Duct Tape Used on HVAC Ducts yarrick19 HVAC 5 06-17-2012 11:29 PM
Garage Insulation yamster Insulation 0 07-01-2011 01:30 PM
Planning on New duct work..any feedback... kilosos2 HVAC 28 01-26-2011 09:21 AM
Properly Sealing HVAC Duct Work craymer45 HVAC 5 11-06-2008 08:47 PM




Top of Page | View New Posts