Bathroom vent placement - basement

[AdamJ2112]

I am trying to determine placement for a bathroom vent as I'm finishing my basement.  The bathroom is 50 sq ft. (roughly 5 1/2' x 9 1/2') with a 2-level ceiling - dividing the long dimension), half of it 7'9", but over the corner shower it is 7'0" because I needed to build a soffit around my waste water pipes for the house. 

The options I'm considering: First, I bought a Panasonic recessed light fan I wanted to install directly over the center of the shower https://smile.amazon.com/Panasonic-FV-08VRE2-Ventilation-Fan-Recessed/dp/B01N7L3FDR/  But will that cause too much steam to float up to the higher ceiling height and get "stuck"?  In this scenario, I can use 4" aluminum snap lock pipe for 16 feet until I use an elbow to vent outside.

Second option, should I place my bath fan at the highest part of the ceiling to pull the humidity?  (If I do, I will need to use flexible piping to exhaust it to the outside to get around other obstructions.)

Third, a suggestion I got during a drywall estimate (not an HVAC guy), recommended I install a wall-mount vent fan and use rigid aluminum pipe.

Which would you suggest? Or is there a better option I'm not thinking of?

[Tom Raymond]

Put it directly over the shower. Make sure it's GFCI protected. Spend the money on a fan timer to make sure it runs long enough to be effective. 

[Jim Katen]

If the bathroom were on an upper level and had a long skylight well, that might be a problem, but a 9-inch difference in ceiling height isn't going to make a scrap of difference here. In a bathroom that size you could put it anywhere on the ceiling or high on the wall and it would work fine. If you put it over the shower, I believe that Panasonic requires it's circuit to be GFCI protected. 

 Be sure to buy and install Panasonic's Condensation Sensor Plus controller (humidistat) or install a good timer, like Tom suggested.  Running the fan for a good 20 minutes after a shower will make much more of a difference than a small difference in placement. 

 

 

[Marc]

16 hours ago, AdamJ2112 said:

I am trying to determine placement for a bathroom vent as I'm finishing my basement.  The bathroom is 50 sq ft. (roughly 5 1/2' x 9 1/2') with a 2-level ceiling - dividing the long dimension), half of it 7'9", but over the corner shower it is 7'0" because I needed to build a soffit around my waste water pipes for the house. 

The options I'm considering: First, I bought a Panasonic recessed light fan I wanted to install directly over the center of the shower https://smile.amazon.com/Panasonic-FV-08VRE2-Ventilation-Fan-Recessed/dp/B01N7L3FDR/  But will that cause too much steam to float up to the higher ceiling height and get "stuck"?  In this scenario, I can use 4" aluminum snap lock pipe for 16 feet until I use an elbow to vent outside.

Second option, should I place my bath fan at the highest part of the ceiling to pull the humidity?  (If I do, I will need to use flexible piping to exhaust it to the outside to get around other obstructions.)

Third, a suggestion I got during a drywall estimate (not an HVAC guy), recommended I install a wall-mount vent fan and use rigid aluminum pipe.

Which would you suggest? Or is there a better option I'm not thinking of?

I would install it at the higher elevation because moist air is lighter than dry air and will rise. You don't want humid air trapped anywhere. I would be sure to choose something at least 80 CF/minute. I live in a humid climate and have had to deal with humid bathrooms many times.

Edited May 20, 2020 by Marc

[John Kogel]

The most quiet exhaust fan is one that in inline with just the intake vent in the room. A really noisy fan won't get used at all. Don't try to mount a ceiling fan on its side in a wall. The fan bearings need to be designed for a sideways mount.

The actual position of the fan in the ceiling is not that critical. It should change all the air in the room in a reasonable length of time. I'd put the fan away from the door, where the makeup air comes in. I wouldn't mount it inside the shower enclosure, not necessary, increases possibility of a shock hazard, like after a tenant breaks or loses the vent cover.

I like the timer switch with the choice of 5 time periods.

In a basement suite, typical low ceiling, Mr. Handy had fixed the noisy bath fan that always came on with the light. He installed a metal-handled toggle switch right on the cover, inside the shower enclosure, yikes.

 

Edited May 21, 2020 by John Kogel

[AdamJ2112]

Thanks to all for the feedback! A couple added details if it makes a difference: I'm in Wisconsin, so not overly humid.  Is there any big concern using flexible piping if I can't place it directly over the shower?  I could move the phone/cable wires easily if I do mount the fan at the highest ceiling point, but I'd prefer the light right over the shower. The light/fan combo is rated safe for over the shower and would have a GFCI circuit.  I do intend to use a timer switch. Attached is a photo of the framing so far if it helps.

[Jim Katen]

6 hours ago, AdamJ2112 said:

Is there any big concern using flexible piping if I can't place it directly over the shower?

The less, the better. Just use the flex to get to the rigid. 

Don't forget fireblocking at that soffit. (It would have been easier to pre-rock that area.)