Composting Toilet vent location

grinnelljd · 10-21-2017, 11:24 AM

We have our Sprinter van on order and have met with the fine people at Sportsmobile North who will be performing our conversion next year. During our meeting, I asked about the possibility of installing a composting toilet, such as an AirHead. They said we'd have to have that install performed by others since they won't install a composting toilet. The install, it itself, is simple so I can do it but I'd prefer to have them install the vent as I'd rather not hack through the body of my new van.

I have some questions about where people have been venting their composting toilet. The initial thought was to run the vent up through the roof of the bathroom, but I have concerns about it being too close to the vent fan location which will be just outside the bathroom door. This may not be a huge issue as I imagine most of the time this vent fan will be operating in an exhaust mode. I've seen others mention venting it through the floor of the van, but I'm concerned then about the possibility of off-putting smells close to the ground.

I'm interested in hearing from those who have installed composting toilets. Where is your vent installed and are you happy with its location?

TomH · 10-21-2017, 03:48 PM

I also will be putting a composting toilet in my high roof 144" Sprinter build from SMB West. They also do not install composting toilets because those are not RIVA approved. RIVA certification is something SMB will not risk losing. I have also heard from some forum members that RIVA compliance makes insurance easier to get and less expensive.

I have a design meeting with Brian at SMB-W this coming Wednesday. This will be on my list of discussion points. I will give a full report in my build thread, but will also post here re. this particular issue.

grinnelljd · 10-21-2017, 05:15 PM

Thanks. I had read on some forum that it was likely due to RIVA certification, but SMB-North didn't offer that as an explanation at the time when we met with them months ago; they just said it wasn't something they could do. They also said they couldn't add a cassette toilet with an outside access door as they weren't willing to cut into the black plastic body molding.

I do hope I can at least talk them into installing the vent for me as I think it will an easy thing for them to do during the build and then I can add the composting toilet, fan and vent tubing myself.

I'm curious as to where you'll eventually decide to install your vent. As I mentioned I was initially looking at a roof location. I was planning to use one of those marine solar fan vent covers that has its own integral battery so it continues to work at night. I've since read that those fans are not recommended for RV use. Not sure why; suction generated at highway speeds, perhaps?. Given that these are apparently not recommended I guess I'll go with an always hot connection from the fan to the house battery; their draw is quite minimal anyway.

When is your van scheduled for conversion? Ours is estimated to arrive in Mar/Apr 2018 and SMB-North said to allow 3 months for the conversion. Once we get a bit further along I guess I'll start a thread here to share my build details and photos.

dford415 · 10-21-2017, 10:44 PM

I have a high roof Sprinter. I did my conversion in Fresno and used an airhead toilet. It works great. I vented out the roof. It works perfectly - no problems and easy to do.

TomH · 10-21-2017, 11:40 PM

Quote:

Originally Posted by dford415

I have a high roof Sprinter. I did my conversion in Fresno and used an airhead toilet. It works great. I vented out the roof. It works perfectly - no problems and easy to do.

Who did the install after you received the van? Could you share any pics/diagrams, please?

To the OP, my build is supposed to start 1/17/18, 12-16 week build time.

TomH · 10-21-2017, 11:48 PM

BTW, our cabinet will have no shower in it, thus no clean, grey, or black connections. SMB-W will build a cabinet behind the driver and facing the passenger side sliding door. It will have double bi-fold doors which fold up against the edge of the toilet when not in use. The doors will reconfigure out into the center of the vehicle when in use. SMB-W has used this system before. I don't know about an extendable hood on top to stop odors from escaping while in use. I will ask about that on Wed. at the meeting. Might need to burn some incense or spray some Lysol. Not sure, but might look something like this:

TomH · 10-22-2017, 02:52 AM

My initial idea was a section that telescoped out and back in like below. That one could have its own ceiling. Brian thought the bifold doors were more practical.

dford415 · 10-22-2017, 09:16 AM

The advantage of Airhead is the power to the fan is located at the fan far away from any possibility of getting wet. In my case I located the fan in the roof a few feet from the house fan. It works perfectly. Because it’s only a fan Sportsmobile was able to put that in (but fan only). I did everything else. It’s easy. Airhead gave me great instructions. Sorry I don’t know how to attach photos but Airhead has lots on their site.

Econoliner · 10-22-2017, 10:00 AM

We have a Nature's Head in a Ford E150 that we've been using successfully for a couple years now. I vent it through the floor behind the left rear tire, which probably doesn't help you Sprinter guys, but what I will say, is that the vent is probably not as big a deal as you think. I only run the fan about half the time. If you're doing everything right--keeping liquids and solids separate and have the right compost material (coir) at the right moisture level, then there is almost no detectable odor. So, I wouldn't stress out on that vent placement. It's not like you're routing an eye-watering, toxic plume, it's really more about keeping the coir moisture level balanced than it is about handling odor. I even saw a youtube video about a tiny house where the owner didn't hook up a vent at all and everything was apparently fine.
Just my 2-cents, results may vary.

grinnelljd · 10-22-2017, 10:56 AM

Thanks. Yes, the fan location was one of the reasons I settled on the Airhead. I was leaning towards roof venting and as you pointed out, having the fan in the roof vent connector makes it much less likely to get wet in a wet bath. I also like the fact that you don't have to open the composting bin to remove the urine container.

I'm glad Sportsmonile was willing to install your vent fan for you. That gives me hope that they will be willing to do the same for my build and I'll add the Airhead myself.

Our current design has a 39 x 24 " bath enclosure with the entire bottom being a large shower tray. I figured I'd get a piece of suitably sized 3/4 inch thick plastic composite material to anchor the Airhead mounts to. Then I can drop this mounting board into one end of the shower pan and clip the Airhead into the mounts. This avoids having to penetrate the shower enclosure with screws to install the Airhead anchors and always us to easily remove it and go to a Porta-pot if for some reason we hated the Airhead (doubtful). I'll probably add some rubber feet to the bottom of the plastic mounting board to allow for drainage so that water doesn't get trapped under the board and cause mold issues.

I had some concerns about the vent location being so close to the MaxAir fan location (just outside the bathroom door), but that fan realistically will be running in exhaust mode most of the time anyway and it's not sounding like the vented air has much smell regardless. Good to hear that your similar solution hasn't caused any issues. I appreciate the feedback.