Insulating Bathroom vent

[Wiz02]

I moved a second floor bathroom light/vent to a new location. Attic is a standard vented type with blown in insulation, soffit and ridge vents.

The existing plastic vent duct, plastic encasing a wound wire, is now too short to connect to the new fan.

Does it make sense to buy some insulated duct? I need about 8ft. Or should I just buy the same duct that is already there.

I am planning on building some sort of air seal out of rigid insulation around the fan where the housing protrudes into the attic .

 

[starquestMM]

Were there any condensation issues with the old setup? if not, id stick with what was working.

 

[Wiz02]

Were there any condensation issues with the old setup? if not, id stick with what was working.

Great point, and no condensation issues, but I since it's a guest bathroom, the shower has seen very little usage.

However, we will be using it all the time when I renovate the master bath.

I think that I will use dryer vent and wrap it with some fiberglass insulation that I have laying around. 25 feet of the insulated duct is like $40.

 

[larry4406]

Insulate the duct.

 

[Wiz02]

Insulate the duct.

Since the majority of the duct run is not insulated, other than being buried in cellulose insulation, does it make sense to insulate just the new piece? Or for the insulation to be meaningful, do I need to replace the entire run?

 

[larry4406]

Great point, and no condensation issues, but I since it's a guest bathroom, the shower has seen very little usage.

However, we will be using it all the time when I renovate the master bath.

I think that I will use dryer vent and wrap it with some fiberglass insulation that I have laying around. 25 feet of the insulated duct is like $40.

Since the majority of the duct run is not insulated, other than being buried in cellulose insulation, does it make sense to insulate just the new piece? Or for the insulation to be meaningful, do I need to replace the entire run?

By your admission it was originally not insulated, and rarely used, which I take as the reason you never had condensation problems. Now after renovation, you will be using it all the time.

Yes, bite the bullet and fully insulate the entire duct. At the day job, we use insulated flex duct.

Or you wait and see and perhaps redo the job again plus condensation repairs.

 

[Wiz02]

By your admission it was originally not insulated, and rarely used, which I take as the reason you never had condensation problems. Now after renovation, you will be using it all the time.

Yes, bite the bullet and fully insulate the entire duct. At the day job, we use insulated flex duct.

Or you wait and see and perhaps redo the job again plus condensation repairs.

Thanks for the push, I knew that digging the existing duct out of the cellulose insulation and replacing it is the right thing to do. I just needed a little help to get out the state of denial.

 

[larry4406]

Thanks for the push, I knew that digging the existing duct out of the cellulose insulation and replacing it is the right thing to do. I just needed a little help to get out the state of denial.

Wonder if you can use the old duct to pull the new one thru?

 

[Wiz02]

Wonder if you can use the old duct to pull the new one thru?

Interesting thought. I will give it a shot when the insulated duct is delivered.

 

[Fav Onefour]

I've used a plastic leaf rake in the attic to move insulation. It helped to lop a little off the handle.
Now is decent weather to do attic work before the heat kicks in full bore.

 

[Wiz02]

I've used a plastic leaf rake in the attic to move insulation. It helped to lop a little off the handle.
Now is decent weather to do attic work before the heat kicks in full bore.

Great idea, thanks