Dehumidifier

[corksil]

So! Seeking simple answers to domestic problems and the resulting domestic solutions.

Let's pretend that a person were to put a dehumidifier in a small bathroom to cut down on moisture in the air after a shower. There is limited ventilation, so the dehumidifier seems like the best option for sucking steam from the shower out of the air and getting the bathroom dried out.

As we know, hot air holds more humidity than cooler air. Also, moisture does not evaporate as readily if the air temperature is cold.

My question is ---- If one were to put a dehumidifier in a bathroom, and it were to effectively dry out the air after a steamy shower ---- at what point would the dehumidifier begin to extract water from a toilet bowl or sink p-trap?

Is there a magic temperature number at which the water in the toilet bowl would begin to vaporize and be consumed/removed by the dehumidifier? The room stays relatively cool, mid 70s probably. It's around 1500 cubic feet and the doors/window remain closed unless the facilities are in use [shower/sink].

If the dehumidifier were to suck water out of the toilet bowl, I would feel as if I were going backwards. Yet -- if it could remove the steam from the air, I would be going forward with my objective.

Any thoughts? Thanks!

[corksil]

FWIW, the dehumidifier is designed for a 1500ft^3 room, and purportedly removes 9oz of water in a 24hr period.

[DannoXYZ]

That's barely over 1-cup water per day. It removes it from the air only, so no need to worry about toilet running dry. I suspect your toilet has more than 9-oz of water in it. In fact, I suspect the showering puts way more than 9-oz into the air.

I think your best bet is to improve ventilation; remove air with moisture in it, and replace with dry air.

[Triple Jim]

If you set the humidistat on the unit to something reasonable like 30 or 40 percent RH, you won't have any unusual evaporation from things like the toilet. It can't "suck" water out of something, it just lowers the humidity in the air.

Personally, I'd find a way to get a vent fan installed, even if it required running a flexible duct some distance. It's much cheaper to run a little exhaust fan than to run a dehumidifier, it works much faster, and it takes up less room in the bathroom. You can even put a timer on the fan switch so it shuts itself off after half an hour or so.

[CaliGrrl]

It shouldn't have any problems with running the toilet dry. Humidifier will take the moisture out of the air, but it's only going to diffuse from the toilet at a slow rate.

[corksil]

Originally Posted by Triple Jim

If you set the humidistat on the unit to something reasonable like 30 or 40 percent RH, you won't have any unusual evaporation from things like the toilet. It can't "suck" water out of something, it just lowers the humidity in the air.

Personally, I'd find a way to get a vent fan installed, even if it required running a flexible duct some distance. It's much cheaper to run a little exhaust fan than to run a dehumidifier, it works much faster, and it takes up less room in the bathroom. You can even put a timer on the fan switch so it shuts itself off after half an hour or so.

Good points. My thinking is that the flow of moisture/condensation/humidity would exist as a cycle. The humidifier would dry the air, which would cause moisture to evaporate from anywhere it could (toilet for example), and the cycle would repeat [at a very slow pace.] There is no RH setting on the dehumidifier. For the 30 dollar cost, that's not an option.

Vent fan is a good option. I need to plan the logistics of that and weigh the cost/benefit.

[corksil]

Originally Posted by CaliGrrl

It shouldn't have any problems with running the toilet dry. Humidifier will take the moisture out of the air, but it's only going to diffuse from the toilet at a slow rate.

Yeah. A slow rate. But that's why I made this thread, because I was wondering how 'slow' that rate was.

[corksil]

Originally Posted by DannoXYZ

That's barely over 1-cup water per day. It removes it from the air only, so no need to worry about toilet running dry. I suspect your toilet has more than 9-oz of water in it. In fact, I suspect the showering puts way more than 9-oz into the air.

I think your best bet is to improve ventilation; remove air with moisture in it, and replace with dry air.

Yep. Which means the hot/humid air must be evacuated and replaced with cold/dry air.

And the dehumidifier does shut off when the water cup has filled.

[Triple Jim]

No cycling involved, it's an equilibrium thing.

Cheap dehumidifiers are the desiccant type, and they're slow. That is, they might bring down the humidity in a closed room if you leave one running long enough, but I don't think you'd be happy with the time it would take one to make a bathroom dry after a shower. Check the water removal per hour specification.

[CaliGrrl]

Toilets don't get sucked dry in arid environments like Arizona. So I don't think that needs to be a concern.

A venting fan would be a good thing if it's practical to do it.

[corksil]

The water removal spec was 9oz/day if I recall properly. That's not much.

At this point the cheapest and smartest long term solution is...... figure out how to remove hot/moist air and replace it with cold/dry air.

And a fan seems to be the most effective way. Have been thinking of an AC for that part of the house for a while now ---- I wonder if running the fan component of the AC would be enough.

Thanks guys!

[DannoXYZ]

Should be OK if your AC is sealed and you're ducting hot/moist air to outside. Blowing cold/dry air in from the outside won't work as well as where is the moisture going?

[Triple Jim]

Originally Posted by DannoXYZ

Blowing cold/dry air in from the outside won't work as well as where is the moisture going?

Don't worry, where he lives there is no cold dry air outside.

[BoBO]

No need to worry about the toilet water. It dries out the moisture in the air, I have 3 dehumidifiers in the storage. At worst, it will ruin indoor plants and dry up your skin since it dries up the vapors in the air if I remember correctly.

It's perfect for mold and allergy issues, but runs up the bill if you have to run it for a while.

[MrAtom]

Take cold showers. It's good for you.