Size of bath ceiling exhaust fan duct

[starflyte1]

Has anyone replaced the exhaust fan/light in their bathroom and knows if the duct is 4 or 6 inches?? I am looking at a new fan light heater but the duct size is 6”.


How hard is it to change the duct size?

[retiredguy123]

Need more information. My duct size is 4 inches. But, why would you want to change it to 6 inches? Are you adding a heat lamp? If the new unit is larger than the current unit, I think the 4 inch duct will work fine with a slightly larger exhaust fan.

[Kenswing]

You can get an adapter to go from 4" to 6" if that will work for you.

[starflyte1]

Thanks for both replies.

I am replacing the current fan/light with a fan/light and heater. The size I want to buy has a 6 inch duct.

I will research the adaptor.

Thanks again!

[villagetinker]

If you have a newer house, the duct may run just to the soffit. The soffit can typically be removed easily, so in theory you would have access to completely replace the entire duct with only needing to install a new exit port (cover) in the soffit.

[kathyspear]

We have a Lantana and I want to replace the exhaust fans in two bathrooms. Would our 20 year old home have 4" ducts? Or does the existing fan have to be removed to find out if I need 4 or 6" Thanks in advance (and sorry for hijacking the thread).

kathy

[Copaleski]

6" is quieter. Get a 6 to 4 inch reducer...should work fine

[crash]

We have a Lantana and I want to replace the exhaust fans in two bathrooms. Would our 20 year old home have 4" ducts? Or does the existing fan have to be removed to find out if I need 4 or 6" Thanks in advance (and sorry for hijacking the thread).

kathy

Your ducts would be 4 inches same as the dryer vent.

[Mohawksin]

Has anyone replaced the exhaust fan/light in their bathroom and knows if the duct is 4 or 6 inches?? I am looking at a new fan light heater but the duct size is 6”.



How hard is it to change the duct size?

May depend on your style of home. Mine is 4 inches. You can remove the grill and measure. You may not have a duct beyond the fan. For most of the villas the exhaust is to the attic, not to the roof and not ducted to the eaves.. There is no duct. In those cases you can use any size fan you can get in the current opening.

[MandoMan]

Has anyone replaced the exhaust fan/light in their bathroom and knows if the duct is 4 or 6 inches?? I am looking at a new fan light heater but the duct size is 6”.


How hard is it to change the duct size?

Just last week I replaced both of my 3.5 sone NuTone/Broan bathroom exhaust fans (the ones that came with the house) with 0.3 sone Panasonic ultra quiet fans. These exhaust 110 cubic feet per minute, and that is plenty. They are very quiet. I put one on a timer at the wall plate, and that is working well. In the guest bath I installed one that turns on automatically when someone enters the room and has a timer built in and also a humidity control. But so far it hasn’t turned off by itself yet, even when I set the humidity level to 80%. Both of these use 4” ducts, and that is what my house has. I assume that yours does, too. 4” aluminum flexible ducts. Panasonic also makes a slightly more powerful fan, 130 cfm, that has a 6” outlet, though you can attach a step down ring for a 4” ring. That’s more than you need.

Here’s the thing about the duct size. These Panasonic ultra quiet fans, when unattached, make almost no noise at all. When attached to a duct, they make less noise than a NuTune, but you can hear them. What you hear, though, is the noise of the air being forced through the duct. (Similarly, with some table fans, the motors are nearly silent, but the air being moved by the fan blades makes noise.) If you were just blowing air into the attic without a duct (which is not allowed), it would be much quieter. A 6” duct with a fan made for a 6” duct will be quieter than with a 4” duct because the air flow is not as fast. But both will be quieter than a noisy fan. Similarly, an exhaust fan with a light in the middle that sucks through vents along the edges will make more noise than the same vent fan without a light because the larger and more direct grill lets air suck through more easily. I put in exhaust fans without lights, though my original fans had light and dedicated circuits for those lights. (I used those wires to add another light elsewhere in the bathroom.)

As for replacing the 4” vent pipe with a 6” pipe, I wouldn’t bother, though the vent pipe is only 3-5’ long and pretty easy to replace. I definitely think replacing an exhaust fan with the quietest one possible is a good move. The Panasonic fans cost more, but I consider it money well spent. They are excellent. Get the 110 cfm fan and save yourself $50. It really is plenty.

As for doing it yourself, it can be done from below instead of from the attic, but even so, you need to stand on a ladder for a couple hours, have the right tools, cut drywall right over your head, use an electric screwdriver by feel, wire the circuits correctly, tape the vent to the fan body with the right kind of tape while working mostly blind. I did it, but it was hard work. If you haven’t done similar work before, I wouldn’t recommend it. I’ve installed a half dozen over the years.

By the way, I’ve just used a decibel meter on my iPad to see how much noise these things make. In my bathrooms, the base reading was 35 decibels, just from environmental noise like air conditioning running in the neighborhood. When I turned on the exhaust fans, that went up to 45 decibels. That may sound loud to you, but with the fans off, the quietest whisper I could make was 55 decibels. So when Panasonic calls these “whisper quiet,” they aren’t joking.

I’ve just reread your question and saw that you are looking for a fan-light-HEATER combination. I don’t think the Panasonic ultra quiet fans with high output are available with a heater built in. You could certainly have a heat lamp installed elsewhere in the ceiling where the powerful fan wouldn’t be exhausting so much of the heat. That would be more effective. I’d recommend having an electrician wire it to a new switch

[retiredguy123]

May depend on your style of home. Mine is 4 inches. You can remove the grill and measure. You may not have a duct beyond the fan. For most of the villas the exhaust is to the attic, not to the roof and not ducted to the eaves.. There is no duct. In those cases you can use any size fan you can get in the current opening.
If the fan exhausts air directly into the attic, it is either a very old house or it was not constructed according to the current building code. An exhaust fan cannot discharge air into the attic space. It must be ducted to the outside.

[GypsyRN]

May depend on your style of home. Mine is 4 inches. You can remove the grill and measure. You may not have a duct beyond the fan. For most of the villas the exhaust is to the attic, not to the roof and not ducted to the eaves.. There is no duct. In those cases you can use any size fan you can get in the current opening.

Not true...I just replaced a soffit cover for my neighbors bath cover which had cracked and had blown off. The size is 4" and it was quite a job taking of the base plate for this soffit outlet. Not impossible, but not as effortless as some would suggest. We live in a CYV and MOST, if not ALL bath and laundry exhausts are vented to the soffits.

[tlivingst]

Just last week I replaced both of my 3.5 sone NuTone/Broan bathroom exhaust fans (the ones that came with the house) with 0.3 sone Panasonic ultra quiet fans. These exhaust 110 cubic feet per minute, and that is plenty. They are very quiet. I put one on a timer at the wall plate, and that is working well. In the guest bath I installed one that turns on automatically when someone enters the room and has a timer built in and also a humidity control. But so far it hasn’t turned off by itself yet, even when I set the humidity level to 80%. Both of these use 4” ducts, and that is what my house has. I assume that yours does, too. 4” aluminum flexible ducts. Panasonic also makes a slightly more powerful fan, 130 cfm, that has a 6” outlet, though you can attach a step down ring for a 4” ring. That’s more than you need.

Here’s the thing about the duct size. These Panasonic ultra quiet fans, when unattached, make almost no noise at all. When attached to a duct, they make less noise than a NuTune, but you can hear them. What you hear, though, is the noise of the air being forced through the duct. (Similarly, with some table fans, the motors are nearly silent, but the air being moved by the fan blades makes noise.) If you were just blowing air into the attic without a duct (which is not allowed), it would be much quieter. A 6” duct with a fan made for a 6” duct will be quieter than with a 4” duct because the air flow is not as fast. But both will be quieter than a noisy fan. Similarly, an exhaust fan with a light in the middle that sucks through vents along the edges will make more noise than the same vent fan without a light because the larger and more direct grill lets air suck through more easily. I put in exhaust fans without lights, though my original fans had light and dedicated circuits for those lights. (I used those wires to add another light elsewhere in the bathroom.)

As for replacing the 4” vent pipe with a 6” pipe, I wouldn’t bother, though the vent pipe is only 3-5’ long and pretty easy to replace. I definitely think replacing an exhaust fan with the quietest one possible is a good move. The Panasonic fans cost more, but I consider it money well spent. They are excellent. Get the 110 cfm fan and save yourself $50. It really is plenty.

As for doing it yourself, it can be done from below instead of from the attic, but even so, you need to stand on a ladder for a couple hours, have the right tools, cut drywall right over your head, use an electric screwdriver by feel, wire the circuits correctly, tape the vent to the fan body with the right kind of tape while working mostly blind. I did it, but it was hard work. If you haven’t done similar work before, I wouldn’t recommend it. I’ve installed a half dozen over the years.

By the way, I’ve just used a decibel meter on my iPad to see how much noise these things make. In my bathrooms, the base reading was 35 decibels, just from environmental noise like air conditioning running in the neighborhood. When I turned on the exhaust fans, that went up to 45 decibels. That may sound loud to you, but with the fans off, the quietest whisper I could make was 55 decibels. So when Panasonic calls these “whisper quiet,” they aren’t joking.

I’ve just reread your question and saw that you are looking for a fan-light-HEATER combination. I don’t think the Panasonic ultra quiet fans with high output are available with a heater built in. You could certainly have a heat lamp installed elsewhere in the ceiling where the powerful fan wouldn’t be exhausting so much of the heat. That would be more effective. I’d recommend having an electrician wire it to a new switch
We are new to the Villages and brought a 4 year old home, we called Munns since they originally installs the HVAC. My husband inquired if they could install a better exhaust fan in our Master Bathroom, totally silence, then told my husband that they don't make changes to the original exhaust fans on Villages homes? My husband asked if they were owned by the Villages and they quickly replied no they were family owned. Is that common for a vendor not want to introduce after market products to The Villages homes?

[MandoMan]

If the fan exhausts air directly into the attic, it is either a very old house or it was not constructed according to the current building code. An exhaust fan cannot discharge air into the attic space. It must be ducted to the outside.

Mine vented into the eaves. That seems to be standard practice. It works fine. You are right that venting into the attic is not according to code.

[Mohawksin]

If the fan exhausts air directly into the attic, it is either a very old house or it was not constructed according to the current building code. An exhaust fan cannot discharge air into the attic space. It must be ducted to the outside.

Ducting out of the attic for my villa built in 2014 is NOT required according to the Villages Design Department.

[Mike Shebel]

It is 4”.

[retiredguy123]

Ducting out of the attic for my villa built in 2014 is NOT required according to the Villages Design Department.
If they told you that, they are not correct.

The 2004 Florida Building Code requires that, "where used, all bath and certain kitchen exhaust fans vent to the outside—not just into an attic or crawl space."

This is covered in Chapter 4 of the Florida Building Code. The code has been revised a few times since 2004, but this requirement has not changed.

[Topspinmo]

Not true...I just replaced a soffit cover for my neighbors bath cover which had cracked and had blown off. The size is 4" and it was quite a job taking of the base plate for this soffit outlet. Not impossible, but not as effortless as some would suggest. We live in a CYV and MOST, if not ALL bath and laundry exhausts are vented to the soffits.

When was it built? I guessing newer rather than older?

[Topspinmo]

If they told you that, they are not correct.

The 2004 Florida Building Code requires that, "where used, all bath and certain kitchen exhaust fans vent to the outside—not just into an attic or crawl space."

This is covered in Chapter 4 of the Florida Building Code. The code has been revised a few times since 2004, but this requirement has not changed.

Plenty of housing around here built before 2004.