Range hood duct to roof vent, which direction?

Reply

  #1  
Old 11-01-19, 04:19 PM
Mixdplate's Avatar
Member
Thread Starter
Join Date: Oct 2014
Location: USA
Posts: 58
Received 0 Votes on 0 Posts
Range hood duct to roof vent, which direction?

Installing a range hood with 7" rigid duct to vent out through the attic, as well as venting out a 4" bath duct that I found exhausting to attic. Does it matter which direction the duct fits into the vent on the roof? From the "few" videos I've seen, the duct is pushed through the roof, and snipped to form tabs. The tabs are bent to the outside of the roof and nailed in place, basically self supporting the duct. The roof vent is then dropped down in to the duct and sealed.

The local big box store did not have a 7" roof vent and I'm not impressed with the quality of what they offered anyway. Ended up ordering both vents from a reputable company online (Luxury Metals). While I'm very pleased with the quality of the vents, they do not fit in to the duct as they are equal in size. Is it ok to reverse the configuration and crimp the ends of the duct to fit up and in to the roof vent? Does it matter which way they fit into each other?

Thanks in advance!
 
Sponsored Links

Popular Reply

 
11-02-19, 03:15 PM
Pilot Dane
Pilot Dane is offline
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 21,377
Received 296 Votes on 270 Posts
The important thing with stove vent ducting is that it is galvanized steel, not aluminum or plastic. Seams should be taped with aluminum duct tape to make them air tight. This is to help contain a fire. Bathroom vent ducting can be almost anything you want.
 
  #2  
Old 11-02-19, 05:33 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 21,377
Received 296 Votes on 270 Posts
You can not connect the stove vent and bath vent. They each need to pass through the roof separately.

I have never seen 7" rigid duct. I have only seen even sizes like 4", 6", 8" and 10". I would make certain you need 7" as that's an odd one. Small range vent hoods might use 6" while higher powered or premium ones usually need 10".
 
  #3  
Old 11-02-19, 08:31 AM
Mixdplate's Avatar
Member
Thread Starter
Join Date: Oct 2014
Location: USA
Posts: 58
Received 0 Votes on 0 Posts
The stove and bath are completely separate. Sorry if I worded this wrong. The Broan 30" hood vent instructions state a 7" duct. Which we are running up through attic and out the roof.

The bath fan was installed previously and we found it vents in the attic. We are adding 4" rigid duct to extend it out the roof.

The roof vents I ordered do not fit into the ducts. Does it matter which way the ducts and vents fit into each other?
 
  #4  
Old 11-02-19, 08:57 AM
Forum Topic Moderator
Join Date: Sep 2005
Location: USA
Posts: 4,769
Received 33 Votes on 32 Posts
All things being equal, I would rather crimp the duct so it fits into the roof vent. This allows the air to move smoothly without hitting the edge of the crimped vent.

It's important for dryer vents, as you don't want lint getting caught, but for an exhaust vent, it really doesn't matter.
 
Mixdplate voted this post useful.
  #5  
Old 11-02-19, 03:15 PM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 21,377
Received 296 Votes on 270 Posts
The important thing with stove vent ducting is that it is galvanized steel, not aluminum or plastic. Seams should be taped with aluminum duct tape to make them air tight. This is to help contain a fire. Bathroom vent ducting can be almost anything you want.
 
Mixdplate, Zorfdt voted this post useful.
  #6  
Old 11-02-19, 05:09 PM
Mixdplate's Avatar
Member
Thread Starter
Join Date: Oct 2014
Location: USA
Posts: 58
Received 0 Votes on 0 Posts
Zorfdt - Thank you! Worked out well with crimped end of duct into roof.
 
  #7  
Old 11-02-19, 05:15 PM
Mixdplate's Avatar
Member
Thread Starter
Join Date: Oct 2014
Location: USA
Posts: 58
Received 0 Votes on 0 Posts
Pilot Dane - Thank you, the roof vents and the duct for the bathroom are definitely galvanized. The range duct is whatever the local big box store carried, which I believe is aluminum as it is not as sturdy as the bathroom duct. All ducts are sealed with foil tape and gaps will be sealed tomorrow with fireblock caulk.
 
  #8  
Old 11-02-19, 06:26 PM
Member
Join Date: Mar 2019
Location: USA
Posts: 71
Received 8 Votes on 8 Posts
Don't forget to insulate the ducts in the attic with R8 foil-faced duct insulation. Also a good idea to spray foam around where the duct enters the attic to prevent air movement.
 
  #9  
Old 11-06-19, 08:51 PM
Mixdplate's Avatar
Member
Thread Starter
Join Date: Oct 2014
Location: USA
Posts: 58
Received 0 Votes on 0 Posts
Dan1973 - That's our plan! Thank you.
 
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
 
Ask a Question
Question Title:
Description:
Your question will be posted in: