Is a Bathroom Fan Necessary?

[MrNoodly]

Part of the dedicated bathroom vent fan issue that seems to be forgotten is that a van isn't very large. It's not a 40 ft RV or 5th-wheel. It's less than 400 cubic feet for an extended low-top van — empty. By the time you have it built out and loaded up (including yourself) the cubic footage is about a third to a half less. Meanwhile, vent fans can move about 900 cubic feet per minute. That means, with a large enough opening (or group of openings) to allow 900 cfm INTO the van (because you need a way to replace the air you blow out), you can completely replace all the air in the van in a few seconds. If you don't want to be drawing bathroom air through the rest of the van on its way out, then put the single vent fan in the bathroom and draw the rest of the van air out through the bathroom.

 

[tx2sturgis]

If you don't want to be drawing bathroom air through the rest of the van on its way out, then put the single vent fan in the bathroom and draw the rest of the van air out through the bathroom.

Several of the posts and the thread title refer to that method of ventilating the shower/toilet area.

Of course, a large Fantastic or MaxAir fan installed above the shower/toilet area is always a good plan, and will ventilate the entire vehicle effectively. But...in the OP the issue is space on the roof for solar panels. So we are back to using a smaller powered vent like the Ventline.

 

[MrNoodly]

Or you mount a big vent vertically on a wall or replacing a rear window. Here's one of Bob's videos:

 

[Dingfelder]

I find it hard to believe you could clear the humidity out of a van you take showers in without resorting to considerable efforts, including at a bare minimum an extra fan(or two) or vent. Low air circulation, high or even moderate humidity, and cool temperatures are what mold loves. I got a severe mold infestation in my own bathroom, in a 17-foot trailer, even though I have used neither my built-in shower nor toilet, and keep empty tanks.,

When it gets cold, I even get water filling in some areas in my window frames and dripping down -- again, with no running water ever, and I drink my coffee cold, not after boiling water for it. I rarely even cook at all, since I have access to other people's kitchens and it's just easier that way.

I now have at least half a dozen chemical dehumidifiers out in my living area and one in almost every cabinet, as well as one running 24/7 on the floor in front of the toilet, where I also have a small fan on a little stand blowing 24/7.

So my having to go to the kind of extreme measures I've never had to use in any house, apartment, or car makes me think that your taking a shower in your van -- a smaller space than my trailer -- is also not going to work without your going to pretty considerable measures.

 

[Dingfelder]

That is, as well as a plug-in dehumidifier in my bathroom. The kind with no crystals, but a water collector you dump out every so often. Oops. It's the other ones that are chemical dehumidifiers.

 

[tx2sturgis]

Sounds like you have a leaky roof and are probably in a humid area. That's a lotta wattah!

 

[Dingfelder]

No leaks, but I'm in the PNW. 76% humidity the other day. Usually I open windows to be sure to air the trailer out so humidity doesn't build up. But now, I keep them closed and crank the heat to lower humidity. You don't feel it because it's cold, but it's apparently quite humid with all the rains and/or cold.

 

[wayne49]

Yes.