Need help with this exhaust problem

[lyban]

I have a finsihed bathroom/laundry room in my basement.
I have attached a sketch of room and a photo of room.
It is about 8 feet by 8 feet by 8 ft. ceiling.
The fan that is there now is old, noisy and vents with the dryer to the outside . The room has just been renovated before we bought house but I guess they kept the old fan.
I put an X on my sketch where the fan is now installed on ceiling.
When using the shower for a few months now, once a day it has already started to smell very musty and there is alot of humidity in room.
My question is: If I put a new Nutone quiet fan and have its owm duct going to outside wall, where would be the best location for me to put it.
Also, how big a job to make a new hole on outside of home in cement.
Thanks for any suggestions.

 

[Jadnashua]

Depending on how it is ducted, the fan joining with the dryer may just be exhausting back into the room through the dryer - IOW, it may not be venting much to the outside. Also, when you run the dryer, some of that may be coming back into the room via the vent fan. So, you may not be gaining much benefit of the current actual venting.

It's also a very good idea to run the fan on a timer. It can take an hour or so, depending on the weather and the room (and how hot a shower you take) to return the moisture to static values.

Is the foundation wall poured or block? You can rent a concrete core drill and make quick, neat work of a new hole. You can use a hammer drill, make a ring of holes then beat it out with a sledge, or use a star drill (special concrete chisel) and do the same thing, but by far, the easiest and neatest is a core drill. It won't have any problems if you happen to hit rebar (if it is a poured wall), either. I like the Panasonic line of vent fans. As you've found, the bigger thing is to find one that is quiet enough that you'll want to run it. Then, make sure you run it long enough. Figure 8-10 total air exchanges per hour and run it long enough to actually help.

Note, if the shower isn't built properly, it can retain a lot of moisture, and this could add to the problem.

 

[Sponsor]

 

[lyban]

Jim

Thank you for the reply.
Can you please explain what you mean by
Note, if the shower isn't built properly, it can retain a lot of moisture, and this could add to the problem.
It seems to drain well.
Is there something else I should look for.

 

[Jadnashua]

Many people think of the tile as the waterproof layer of a shower...in reality, especially on the floor (pan), the waterproof layer is burried underneath the tile. Some installers, especially in a basement on concrete, seem to think the rules of nature don't apply, and either do not install a waterproof liner, or choose to install it flat on the floor. Any moisture that does migrate into the floor of the shower needs the waterproof layer to be sloped so it will drain. The shower drain actually has weep holes beneath the top grill that allow that (or it should! and they must be kept clear during the construction process to work). If the shower doesn't have a liner, or if the liner was installed flat on the floor, over time, all of that concrete underneath the tile can become saturated. This in and of itself can be a source of some nasty smells and the constant moisture can promote mold growth, which is another source. The tell-tale signs are dark grout joints (wet) that never seem to dry out on the pan and possibly lower walls. ANother common mistake is to use nails to fasten the liner or the surfacing material to the top of the curb before tiling. There should only be nails on the outside of the curb...not in the top or insides. This is true in the liner up the wall...no fasteners below the top of the curb.

It usually takes at least several years for a shower to smell if built wrong and saturate the pan...the pH of the concrete acts like a buffer, keeping the environment hostile. It can provide a constant source of moisture to the room, however. Eventually it usually becomes more acidic, and stuff starts to grow. If it is built to drain right, that'll never happen.

 

[lyban]

Thanks for the answer. Since I have no idea how the shower was built, I guess the best thing is to put in a decent fan with its own venting rather than along with dryer for now. Would you agree with this?
If so, any idea from my photos where would be the best place for fan.
Thanks

 

[Jadnashua]

Humidity diffuses throughout the room, so it probably doesn't matter all that much. If you choose to add one with a lamp and/or a built-in heater, then you might want it in front of the shower. The hassle may be the windows and hopefully, the joists run out towards the foundation wall, or it will be a bear getting the new vent run.

 

[lyban]

Jim

We were lucky. We took out cabinets in room above the washer and dryer and made a hole in drywall and found the duckwork. It was going to outside wall but not really in the cement but in the window casing. So my husband made another hole in window casing and attached new ducking for the fan and capped off the part of dryer duck that was going to fan. we now have two seperate ducks so hope that this will alleviate alot of the problems. Also discovered that the dryer vent (only vent at that time) was completely clogged up with lint. We will try this for a week or two and hope it works, then we will buy a new quieter fan, I think the one in there is quite old.
Your help was much apppreciated.

 

[Jadnashua]

Lint in a dryer duct is a fire hazard...you need to blow or clean them out periodically. ANd, the dryer duct should not be the plastic flexible stuff...it costs you money because it slows the air down, and when it slows down, it drops out more lint. You really want solid metal ducting.

 

[GabeS]

I agree. Solid metal ducting. Don't use sheet metal screws to attach pieces together. Just use metal foil tape. The lint will build up on the screws if you use them over time. I would definitely vent seperately.

 

[GabeS]

I'm also very surprised with that big renovation you did, they neglected the venting and ducts. We are talking about very inexpensive materials and very little amount of labor to do the venting, especially when ceiling is open.