Bathroom Humidity - Solutions Needed

[Anonymous]

Anonymous wrote:

Anonymous wrote:Certainly a weird one.

Will the fan hold a paper plate? Toilet paper is super light and doesn't signify much suction itself.

If you open a window somewhere else nearby in your house and with the intervening doors at least ajar, what happens with the ceiling fan running?

We live in Southern California so our windows throughout the house are generally open from dawn to dusk. We don't have paper plates so not sure if it will hold. We purchased a more powerful exhaust last night,which will be installed next week, along with the more powerful dehumidifier.

Well I hope you don't run the HVAC with the windows open! If you're not running the HVAC the vent isn't going to make a difference.

[Anonymous]

Anonymous wrote:Where does the replacement air come from?

It leaks in. Windows, doors and even walls aren't air tight. If there are other vents in the house that aren't running they will leak in reverse. If you have a fireplace it will even come down the chimney.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Something else is going on.

Let's say it's a big bathroom and it's 200 square feet. With eight foot ceilings that's 1600 cubic feet. A minimal exhaust fan will exhaust 100 cubic feet per minute, so in 16 minutes it will completely exchange the air in that room. Changing the air should get rid of all the humidity.

My bet is the exhaust fan isn't actually working. It happens all the time that the exhaust gets blocked, the vent on the outside gets painted shut by painters or the hose gets pinched in the wall or something builds a nest in it. It also happens all the time that it was never hooked up properly to begin with. It can also happen that the fan blade breaks and even though the motor is turning it's not moving any air. If you light an incense stick under it it should easily suck all of the smoke out of the room.

The other possibility is there's another source of humidity other than the shower -- most likely a plumbing leak somewhere. But I'd check the fan first.

DH and I checked on whether or not it was actually working. The exhaust butts up against an exterior wall, so we went to the back of the house where the exhaust "exhausts" out, we could feel the air coming out. It felt quite surprising how much air was coming out, it felt like a fan.

The bathroom is about 125-150 sqft. The window is inside the actual shower stall, as is the new exhaust fan. Just like in this image:

110 CFM fan means almost 2 cubic ft of air per second. You should feel pretty strong blow out. And the air should feel very heavy w/ moisture. Is that how it felt?

Typically a bath fan will have a 4" duct, which has a cross section of 12.5 inches. At 110 CFM the air has to move at 21 feet per second or about 14mph. That will feel like a stiff breeze. To get a feel, find a quiet street and drive that speed while holding your hand out the window.

[Anonymous]

Get a thermometer with a humidity gauge like this one:
https://www.amazon.com/gp/product/B01H1R0K68

less than $10 on Amazon.

Take some readings in the bath before and after a shower and report back to us. It would also be helpful to know the outdoor temperature and humidity.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Something else is going on.

Let's say it's a big bathroom and it's 200 square feet. With eight foot ceilings that's 1600 cubic feet. A minimal exhaust fan will exhaust 100 cubic feet per minute, so in 16 minutes it will completely exchange the air in that room. Changing the air should get rid of all the humidity.

My bet is the exhaust fan isn't actually working. It happens all the time that the exhaust gets blocked, the vent on the outside gets painted shut by painters or the hose gets pinched in the wall or something builds a nest in it. It also happens all the time that it was never hooked up properly to begin with. It can also happen that the fan blade breaks and even though the motor is turning it's not moving any air. If you light an incense stick under it it should easily suck all of the smoke out of the room.

The other possibility is there's another source of humidity other than the shower -- most likely a plumbing leak somewhere. But I'd check the fan first.

DH and I checked on whether or not it was actually working. The exhaust butts up against an exterior wall, so we went to the back of the house where the exhaust "exhausts" out, we could feel the air coming out. It felt quite surprising how much air was coming out, it felt like a fan.

The bathroom is about 125-150 sqft. The window is inside the actual shower stall, as is the new exhaust fan. Just like in this image:

110 CFM fan means almost 2 cubic ft of air per second. You should feel pretty strong blow out. And the air should feel very heavy w/ moisture. Is that how it felt?

Typically a bath fan will have a 4" duct, which has a cross section of 12.5 inches. At 110 CFM the air has to move at 21 feet per second or about 14mph. That will feel like a stiff breeze. To get a feel, find a quiet street and drive that speed while holding your hand out the window.

You can buy a cheap anemometer on Amazon for about 15 bucks. That will give a ballpark estimate of how much air the fan is moving.

[Anonymous]

I looked at the picture of your bathroom and it looks really similar to ours except ours doesn't even have a window and we are in D.C. where it is really humid. The only time we had a problem with humidity in the bathroom we had a small slow leak from the upstairs bathroom. It wasn't bad enough to show up on the ceiling but inside the ceiling it was really wet and when someone would take a shower it would take forever to dry.

We were luckily remodeling and caught the leak before it made lots of damage. We had to tear out the whole ceiling and the entire upstairs bathroom floors to fix the upstairs pipes and have had no issues since.

[Anonymous]

What is the humidity like before the showers? That might tell you if you have a water or moisture problem unrelated to the fan. Your contractor sounds bad and is it possible they are venting humid air from somewhere else into the walls?

[Anonymous]

Consider the benefits of a whole-house dehumidifier, e.g., https://www.aprilaire.com/whole-house-products/dehumidifiers If you experience high humidity in other rooms at other times, a whole-house unit can save on your AC costs and can be much more effective than a room unit which has to drain or have a bucket emptied periodically.

[Anonymous]

Anonymous wrote:Consider the benefits of a whole-house dehumidifier, e.g., https://www.aprilaire.com/whole-house-products/dehumidifiers If you experience high humidity in other rooms at other times, a whole-house unit can save on your AC costs and can be much more effective than a room unit which has to drain or have a bucket emptied periodically.

OP said she leaves the windows open almost all the time. Running a whole-house dehumidifier in those conditions would be pumping money out the window.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Fan's not properly connected to exhaust pipe. Your exhaust air should be really damp and moisture heavy.

I'll have to wait for one of my kids to take a shower (it's only 10am here), then I'll go outside to check on what that exhaust air feels like.

It should be REALLY heavy air and cover your hands with heavy moisture. Remember if blowing 2 CFSecond, that's pretty strong blow.

Okay we tried it. The air that comes it is very warm, and very most and heavy.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Certainly a weird one.

Will the fan hold a paper plate? Toilet paper is super light and doesn't signify much suction itself.

If you open a window somewhere else nearby in your house and with the intervening doors at least ajar, what happens with the ceiling fan running?

We live in Southern California so our windows throughout the house are generally open from dawn to dusk. We don't have paper plates so not sure if it will hold. We purchased a more powerful exhaust last night,which will be installed next week, along with the more powerful dehumidifier.

Well I hope you don't run the HVAC with the windows open! If you're not running the HVAC the vent isn't going to make a difference.

We live by the ocean, so the HVAC runs only a few of months during the year. One month during the summer, usually August. Then in the winter starting around late october. Also by "running it" I mean - during winter months only in the morning to get the chill out of the air. And during the summer usually starting early afternoon.

[Anonymous]

Anonymous wrote:Consider the benefits of a whole-house dehumidifier, e.g., https://www.aprilaire.com/whole-house-products/dehumidifiers If you experience high humidity in other rooms at other times, a whole-house unit can save on your AC costs and can be much more effective than a room unit which has to drain or have a bucket emptied periodically.

We do not have a whole house dehumidifier. When we lived in Bethesda we did, but when we moved to Southern California there was no need for it.

[Anonymous]

Anonymous wrote:What is the humidity like before the showers? That might tell you if you have a water or moisture problem unrelated to the fan. Your contractor sounds bad and is it possible they are venting humid air from somewhere else into the walls?

When no one is showering and the humidity has had time to exit the bathroom...and we wipe the ceilings and walls down to remove whatever residual moisture we can, the bathroom stays dry.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Fan's not properly connected to exhaust pipe. Your exhaust air should be really damp and moisture heavy.

I'll have to wait for one of my kids to take a shower (it's only 10am here), then I'll go outside to check on what that exhaust air feels like.

It should be REALLY heavy air and cover your hands with heavy moisture. Remember if blowing 2 CFSecond, that's pretty strong blow.

Okay we tried it. The air that comes it is very warm, and very most and heavy.

So it sounds like the fan is working. Is it properly sized? I know you were going to get one.

If after that you still have water on the ceiling long after a shower, something else is the issue.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Fan's not properly connected to exhaust pipe. Your exhaust air should be really damp and moisture heavy.

I'll have to wait for one of my kids to take a shower (it's only 10am here), then I'll go outside to check on what that exhaust air feels like.

It should be REALLY heavy air and cover your hands with heavy moisture. Remember if blowing 2 CFSecond, that's pretty strong blow.

Okay we tried it. The air that comes it is very warm, and very most and heavy.

So it sounds like the fan is working. Is it properly sized? I know you were going to get one.

If after that you still have water on the ceiling long after a shower, something else is the issue.

We purchased a more powerful one which arrived yesterday. It's being installed next week. Fingers crossed this helps. I would settle for a 50% improvement at this point