Promaster low floor bad, or not so much

[booster]

There has been quite a lot of discussion about the Promaster, both for and against. As usual, a lot of the comments against are based on "what I happen to own is better" syndrome, but that is pretty normal when consider what class b's cost and how personally folks take their decisions (we all do it). One of the big issues is the low floor's effect on tank placement.

I don't have a dog in this fight, but it sure appears to me that, done right, this could be a positive, not negative. Could it be done so that the van could be used in moderately cold weather without special actions? Can you keep most of the fragile hardware that hangs under all our vans out of harm's way? Those would be huge pluses.

Fresh water tanks can go anywhere, the water is always pumped to the point of use, so no problem with it inside, except space.

I think it is, or was, Sportsmobile that used a toilet that actually sat on top of the black tank, inside the B, which works OK as the toilet is the only source of black water. Toilet would sit a bit higher. Problem? Depends on how the rest of the van is done, I would think.

The grey water from the sink(s) would also not be an issue as it drains from high enough to be able to run to an in van tank. That leaves the shower drain, which sits too low to get to an in van tank and would require a small sump pump. This is easy because there are no solids, and very minimal height would be needed.

Just think how well these high tanks would drain!

I have seen TV ads recently for stand alone bathroom setups for home basements that require no underfloor plumbing. The toilet, sink, and shower all run to a small tank under behind the toilet and are macerized and pumped up to the nearest sewer line. Lots of existing technology out there.

Tanks, if inside, can be very efficient in space usage, as they can be molded to fit around all the odd obstructions like wheel wells, gas fillers, spare tire humps, body curves, whatever.

I hope the folks designing the Promaster and other new van class B's take a step back and look "outside the box', to use an overused term. Convention and familiarity tend to make us more accepting of the same old, same old, and that may not always be the best. Push the envelope and see what you can come up with.

If I were in the market to do a DIY class B, I think it would be an interesting adventure to try, as it has lots of potential.

[markopolo]

I keep seeing the DIY possibilities with the ProMaster. I was thinking like you about keeping all the plumbing inside including the tanks. Underneath the van would be stock except for a generator if needed. I'd place the tanks under cabinets, fridge, closets etc. Exterior storage would be in a rear cargo box.

[markopolo]

It doesn't look like there is much space under the Ram ProMaster on the short wheelbase model.

Photo from Safari Condo. Click http://www.safaricondo.com/index_eng.php to visit.

[Davydd]

Pros:

DIY. Easier to work inside than underneath.

Cold Weather. Everything (plumbing) inside.

Anything outside under the floor is subject to environmental and mechanical damage.

Cons.

Outside the box work arounds that may not be the most convenient solutions such as unlevel floors, step ups and non-standard odd heights.

Everything inside subtracts from potential storage space.

So far what's been proposed all have smaller capacity tanks. Choice or limitation?

[mlts22]

This exactly is why I keep getting attracted to a Sportsmobile upfit. It may cost some cash over a Travato, but one could have a macerating toilet put in and have the black tank in the van itself if one so chose.

I like looking at European vans as examples. Europe RV makers have not gone to the "cheaper is better" that US makers went to in '08, and have been ever since, and even though most of their rigs do not sport the shiny veneers that the Airstreams do, they have solid, usable floorplans. Most of the floorplans are very family friendly. However, European RV parks in general are a lot more primitive than here. They might have a storm drain for emptying grey water, then a pit for the cassette toilets.

The downside of European vans is the fact that Europeans live a different life than we do. By law, they get at least four weeks of vacation a year, so they often will head to a campground and stay there for weeks on end. This is why they use the awning annex tents. A couple hours setup and take down once a year isn't bad. With the annex tent up, the "B" is mainly a kitchen, bathroom, and storage. Most of the time spent is spent in the screen room or outside hiking/biking/tent camping.

Here in the US where vacations are shorter, the annex tents are too time consuming to put up and take down for a weekend.

Of course, there is the generator issue. I wonder how Winnebago placed the Onan because when I took a look underneath, there just wasn't any space for one. I am guessing they probably cut through the floor, welded a sheet metal vapor barrier in place so no generator exhaust could wind up in the passenger compartment, then installed the genset that way. It works, but it does cut down on interior space by a good amount.

I am hoping for some cleverness in upfitting the PMs, but unfortunately, even I, with my rose colored glasses, see some issues. In Europe, the low clearance can be dealt with by ordering a Ducato with rear wheel drive or AWD. Not so in the US.

[WJones]

Booster,

I agree with your "what I happen to own is better" syndrome. If people would only realize that my model is the best, all these discussions would end - but what can you do, it's human nature!

OK ... seriously ... the issue you brought up about the space required for these tanks isn't a trivial one. With the way we sometimes use our RT I can't imagine having tanks that are smaller than the ones we've got (boondocking at festivals, etc) , or having less storage (longer stays in campgrounds). Looking at the underside of our unit, it seems to me these tanks would occupy a good proportion of our storage space if they were all inside.

Having said that, I do agree it would be nice to have all the plumbing in the heated part of the vehicle and be truly 4 season.

William
2000C200P

[mlts22]

A "B" van is all about compromises. At the SMB shop, I saw a Sprinter being upfitted with an Onan Marquis 7k generator, completely inside the van itself. The generator had an enclosure built around it with a sheet metal vapor barrier to keep any gas from entering the inside of the van. Inside the enclosure was a significant amount of acoustic and thermal shielding as well.

I can see tanks being inside the vehicle, but it will cost in living space. A compromise might be insulation (Thermablok aerogel insulation is, AFAIK, the best around for R factor per thickness) around the tanks, combined with a heating pad. The FW tank could be heated by an on demand water heater and a recirculation system that moves water in a pipe around the plumbing then through a radiator near the grey and black tanks before the water winds back in the FW tank. There is a Sportsmobile build where the owner had this put in. It is mentioned on the Sprinter sub-forum. Of course, the recirculation system will take up space and use energy, so that is another trade-off, but it might be a decent compromise to keep tanks warm.

There are other ways to deal with tanks. A cassette toilet means one less tank underneath needing to be kept warm, but it also means a bigger hassle trying to empty in sub-freezing weather.

[bobojay]

You guys keep talking about the black tank being inside the vehicle. This is how most of the Sprinter and Chevrolet B's I've seen are set up.
Our ERA's is on the inside with the dump valves directly below. Only one 90 degree turn in the plumbing below the black tank...

[Davydd]

I never thought about it that way but looking at the elevated tank in this photo I took at the factory of my Legend before the toilet was mounted it looks as if the pedestal area about the floor could be the whole black tank. I kind of assumed looking inside the tank through the toilet that it appeared deeper than the floor so thought maybe the floor was cut and the tank was half and half through the floor but that would not make a lot of sense. I'll have to look underneath.

[booster]

Our 07 Roadtrek on a Chevy, aisle shower, also has the toilet raise something like 6", but the tank is underneath the floor completely. I think they may do it to make sure slosh while driving can't get to any point that might leak.

[markopolo]

My van has something very similar to David's photo. There's the inner tank that supports the toilet but I also have a large waste tank under the van. On my van the two tanks are connected via ABS pipe under the van. Waste in the inner tank drains to the exterior tank.

[Mike]

Originally Posted by booster

Our 07 Roadtrek on a Chevy, aisle shower, also has the toilet raise something like 6", but the tank is underneath the floor completely. I think they may do it to make sure slosh while driving can't get to any point that might leak.

Is yours set up for some sub freezing camping, with split tanks, smaller one inside and the larger black tank underneath? - removed most of this paragraph. It appears most 190s and 210s have the dual fresh tanks for cold weather use.
If you could situate the fresh and holding tanks inside the body, that might be a desirable feature for folks who prefer cold weather or all season camping. We usually prefer comfortable daytime temperatures and drier climates at altitude, but they sometimes come with low overnight temperatures as a trade off.

Another thought about tanks inside, is having the fresh tank on the same horizontal plane, or above, as the water heater. I've always wondered how they don't drain back into the fresh tanks which are usually below them under the floor, when not in use. I guess there might be a one way check valve at the heater input low point. "Do not run water heater with tank empty. Make sure water heater tank is full before use." is the type of warning that you tend to heed. It's probably one of the most expensive mistakes you can make. It always makes me wonder how the heater tank stays full with gravity trying to empty it back into the source tank.

[accrete]

A comment on cassette toilets...a prior rig my wife & i had utilized a Thetford C402C Cassette toilet. At first i was excited about this unit as i did find it was easy to empty and relatively painless Though for us and our style of boondocking, we found the ~3 day capacity for 2 adults to be a hindrance. If we had kept the rig we would have purchased a second cassette so we could have at least our normal ~5 or 6 days between visits into town to restock (and in the case of the cassette...finding a suitable place to dump such as a public restroom.)

Now...continuing on the potty idea, for those considering some out-of-the-box ideas i would include some research on the newest separating-composting toilets such as Natures Head, Separett, and others. We went this route in our van and are now able to go a week or longer between _dumps_ with two adults using it full time. During one email volley with SMB they are willing to install these toilets as an option/expense. No black tank, and urine is plumbed into grey tank per code.

On showers with sump pumps... yup, that is what is in use in our 15ft Parkliner fiberglass trailer we tow behind our van. The grey tank is located above floor and inside the rig so there is a simple sump pump activated by a manual marine-grade switch inside the shower after each use. The water is pumped ~8ft horizontal and ~12" vertical to the grey tank. Your feet are on a bamboo floor and out of water during the shower.

Thumbs up on water supply on the inside...Cari and i have found ourselves unexpectedly in unseasonable snow storms and with all our water tanks above floor have never had plumbing issues.

Cheers,
Thom