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Bathroom Fan Vent IS Dundas Jafine Draft Blocker 4 inch Necessary?

Bathroom Fan Vent IS Dundas Jafine Draft Blocker 4 inch Necessary?


  #1  
Old 02-07-22, 08:25 AM
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Bathroom Fan Vent IS Dundas Jafine Draft Blocker 4 inch Necessary?

Gonna install a bathroom fan in MB bath, the other bathroom, both sharing a wall has a fan that is vented to the attic.
MB bath has no attic, my plan is to install the fan on the wall since there's an attic behind that wall, and that attic is above 2nd bath. I want to use a hvac Y connector and vent both bathrooms into one roof vent.
Because of the height to the roof and need for each fan having it's own starting duct that plugs into the WYE connector, the Broan complete kit is not ideal.
MATERIALS
I want to use a
1- 4 inch regular HVAC insulated duct since I can cut it to size.
2- Is it necessary to instal a Dundas Jafine Draft Blocker 4 inch?
3- 4x4x4 wye
4- 60 sq. in. NFA Aluminum Slant Back Roof Louver Static Vent in Black

Do you see anything I should change/not use or swap for another item?
I would want to do this job so the house can pass inspection aka upto to code even though it's an upcoming rental, luxury budget not necessary but just within a reasonable one.
 

Last edited by bambata; 02-07-22 at 09:31 AM.
  #2  
Old 02-07-22, 11:02 AM
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It's been said that you should not vent two bathrooms into one stack. Back flow can occur. You best bet is to vent both fans separately through the roof. Once you do one the other will be easy. I just did that this past summer on my bath remodel.
 
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Old 02-07-22, 11:13 AM
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Ok that makes sense.

what about the materials I have linked for this project, any opinion them?
 
  #4  
Old 02-07-22, 11:24 AM
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I just use a straight rigid non-insulated 4" through the roof. Supposedly that can cause condensation to drip down the pipe and soak your insulation or ceiling. I have not found that to be the case. But insulated is good!
The draft blocker may negate the need for two pipes and you may be able to use the one vent type. I'll let the xperts here comment on that. But I would still want the vent blocker. On windy days my old vent will rattle something crazy. The roof vent seems fine.
 
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Old 02-07-22, 01:22 PM
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Normally you shouldn't connect two vent fans together.
If you do.... the line after the wye should be at least an inch larger than the supply lines.

I have no idea what those dampers are but vent fans aren't all that powerful.
If it has its own damper and you add a second one.... I don't know if they'll both open.
 
  #6  
Old 02-07-22, 01:57 PM
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I'd install a remote fan in a 6" duct after your wye. Either switch would activate it.

https://www.homedepot.com/p/Viagrow-...-V6F/204764793
 
  #7  
Old 02-09-22, 08:38 AM
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I will do 2 fans since I had those in storage, and the Broan fan kit. Turns out the attic isn't as tall. The only thing is I see few folks in reviews complain about condensation with the Broan kit. Well I could wrap it with Frost King Fiberglass pipe wrap but it's half an inch thick.
1- Do you guys think this is sufficient or double it ? And
2- will this meet code?
3- one fan only needs 2-3ft of duct. The kit has a 5ft duct. Should I cut to size? Is it a problem if the "ribs" are not completely stretched out may be worth condensation?
4- to combat potential condensation drip I see done folks say to let the duct have a little U drop to collect the same. What do you guys think of this?
 
  #8  
Old 02-14-22, 10:19 AM
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Installed the two fans separately. Master bath fan is installed on wall and it's louder compared with the other one installed on ceiling. Wondering if there's any ideas you can suggest to quiet the noise down a notch or two?
 
  #9  
Old 02-14-22, 11:14 AM
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What brand do have? I noticed the Nutones/Broan are much noisier than the Panasonics.
 
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Old 02-14-22, 01:32 PM
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The suggestion was made earlier to have a remote fan. Remote fans are almost silent when they are running. Because they take the place of the fan motor in the bathroom.
 
 

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