Panasonic bath fans

[nizak]

I have a customer who is requesting that the bath fans be extremely quiet. I generally use Broan QT series which operates at 1.5 sones.

Customer has heard these operate and wants a considerably quieter unit.

I am looking into the Panasonic line which says they operate at .3 sones.

In looking at the mounting, it appears the flange of the housing attaches directly to the bottom of the I joist. That does not allow for the conventional (Broan at least) 5/8" portion that hangs down allowing a flush surface when drywall is installed.

Seems odd that the housing would set up into the ceiling 5/8".

Has anyone here used Panasonic? If so, any feed back would be appreciated.

Always leary about using a new product, especially something that can't be easily replaced if it does not perform well.

Thanks

 

[JoeyD74]

I use them in every job unless someone asks for a different one, then I educate them on the performance and quietness of them and typically they choose to use them.
They mount with extension bars so you can set the height where you want it.

 

[edlee]

I have a customer who is requesting that the bath fans be extremely quiet. I generally use Broan QT series which operates at 1.5 sones.

Customer has heard these operate and wants a considerably quieter unit.

I am looking into the Panasonic line which says they operate at .3 sones.

In looking at the mounting, it appears the flange of the housing attaches directly to the bottom of the I joist. That does not allow for the conventional (Broan at least) 5/8" portion that hangs down allowing a flush surface when drywall is installed.

Seems odd that the housing would set up into the ceiling 5/8".

Has anyone here used Panasonic? If so, any feed back would be appreciated.

Always leary about using a new product, especially something that can't be easily replaced if it does not perform well.

Thanks

You can screw the flange to the bottom of the joist. It works. I've installed a lot of them.

 

[kwired]

Big tip to make a quiet fan even quieter is to not undersize the ducting. Just because it has a 4 inch discharge doesn't mean you should run 4 inch duct.

I have had Broan/Nutone QT series that you almost can't hear at all and some that leave you wondering why they are not as quiet as other installations were with the same unit - it is usually the ducting.

Asked an HVAC guy one time what size duct I needed for 110CFM - he said 6 inch, yet most 110CFM fans have 4 inch outlet and most don't know any better and just connect 4 inch duct to them. Increase to 6 inch and keep elbows to a minimum will reduce restistance to air flow and will make that blower operate quieter. Also remember flex duct has more resistance to air flow then smooth rigid duct, so if using flex you need to increase size to compensate for resistance to flow.

The quietest fans are when you have an inline type duct fan that is not right at the inlet - then whatever fan noise that is present is not right in the room that you want to be quiet. They are not really all that much more expensive either then some of the quietest "bath fans", and can be duct-ed to more then one room as well which may cost less then having two QT or other premium fans.

 

[GerryB]

You can screw the flange to the bottom of the joist. It works. I've installed a lot of them.

Ditto. Use the stem for the other side. I've used them for remodel and had to cut the rock off the joist. I think they are designed to be that way as opposed to the Broan, nutone etc.

 

[nizak]

Thanks for the input.

 

[Fulthrotl]

Has anyone here used Panasonic? If so, any feed back would be appreciated.

Thanks

i've got two of them in my house. i won't use anything else.

the 340 CFM unit will pull the bathroom door open about 6"
if it isn't latched when you turn it on. dead quiet.

 

[ptonsparky]

i've got two of them in my house. i won't use anything else.

the 340 CFM unit will pull the bathroom door open about 6"
if it isn't latched when you turn it on. dead quiet.

That has been my experience with the one we have.

Quiet is relative...I have not heard crickets for several years now.

 

[George Stolz]

Just be advised that if you use the ones that aren't meant to shut off, and you wire them that way, then there's a pretty good chance it'll wind up on a warranty call.

 

[Dennis Alwon]

The size of the duct is not as important as the duct itself. You should use insulate duct especially if the duct is in the attic. The softer duct will dampen the sound. I have never had an issue with using 4" duct but others may be more cognizant than I.

The flange the op talks about does not mount to the bottom of the joist but is for the fan.... At least the ones we use. My guys retrofit these all the time with no issues.

 

[kwired]

The size of the duct is not as important as the duct itself. You should use insulate duct especially if the duct is in the attic. The softer duct will dampen the sound. I have never had an issue with using 4" duct but others may be more cognizant than I.

The flange the op talks about does not mount to the bottom of the joist but is for the fan.... At least the ones we use. My guys retrofit these all the time with no issues.

Sorry man but that is not my experience. If motor is on the far end then flex duct dampens sounds, if motor is on same end you are on it takes more power to push same amount of air through a flex duct because the corrugations in the duct will increase airflow resistance this will make the motor and fan sounds louder, it may make them louder if fan is no far end as well but you already have that sound source away from you so you don't notice it.

Air velocity makes a huge difference. You can move same CFM in a larger duct but at lower velocity and have lower sound levels from duct noises alone. The QT fans or other ultra quiet lines all use larger blower wheels and operate at a lower speed - yet still move similar amount of air as the economy priced ones, but you can help them become even quieter with some wise ducting practices.

 

[Dennis Alwon]

I spoke with engineers at Fan Tech and they say it makes absolutely no difference which end the fan is on. I said I thought it took more for a fan to push air then to draw air and they said that is simply not true.

 

[Buck Parrish]

I've been letting the customers get the fans. It seems most of them use Amazon a lot any way. I do recommend Panasonic. Even the one that mounts in the attic is nice on a large bath.

 

[kwired]

I spoke with engineers at Fan Tech and they say it makes absolutely no difference which end the fan is on. I said I thought it took more for a fan to push air then to draw air and they said that is simply not true.

I agree with that. The fan moves same amount of air no matter which end it is on, the duct will have a resistance to airflow that will vary depending on size, static pressure and characteristics of the duct such as smooth vs corrugated inner walls. The amount of sound that is emitted will be different at the fan end then at the opposing end regardless of if it is pushing or pulling the air, unless duct is really short length then any difference may not be too noticeable.

You can either experiment with this just for curiosity sake or just ignore anything that has been mentioned here, since you seem to think I am full of it here. You can even block the discharge of an existing installed fan (possibly simplest thing to experiment with) and I bet most cases you find the fan is louder with blocked (fully or partially) discharge. Maybe won't be to noticeable with "economy" fans but is with the "quiet fans".

Before I started running larger duct to such fans I had installed same model of fan in multiple locations in same house - and got different sound levels out of them, most noticeably quiet was the ones with very short duct run, less turns, etc. - less air flow resistance in those.

 

[FionaZuppa]

well, is there room? i use fantech inline fans when i can. since the motor/blades are not at the ceiling the noise is very minimal. and the best price that i could find (retail) was at supply house dot com. in retrofit cases i remove the old ceiling mount motor and keep the housing there since it has the damper, then mount the inline somewhere else. of course, only if mounting a inline of this size is feasible, but you can mount them horizontal to vertical.