Toilet facilities in Caravans

We have been cassette users for the last 17 years.
Pros - simple, cheap(er).
Cons - needs emptying every 3-4 days (2 people full time), needs to be disposed of into a dump point or burried.
HOWEVER, we recently discovered that if urine is diverted, emptying frequency can be extended significantly, maybe to 14 days (for 2 people full time). How you divert the urine is an ongoing question.

I am currently building a second vehicle. It will probably get a Natures Head composting toilet. Others are available, but "oils are not oils".
Pros - emptying can be up to about 4 weeks (2 people full time), can be disposed of into a rubbish bin or burried. Urine is seperated and can be disposed of seperately every 3-??? days depending on collection container.
Cons - more expensive, needs a composting 'starter'(about brick size), needs to be emptied into a compostable plastic bag, needs a small fan 24/7 (very low power), struggle at very low temperatures unless heated.

Black tank - I would never consider one. The only difference to a cassette is more complexity (and failure potential) and extended emptying times, but that emptying is more restricted - you can not empty into a dump point or burrying hole 50 metres from the vehicle without a bucket and multiple unpleasant trips.

Empting 2 cassettes in the Simpson.

Cheers,
Peter
OKA196 motorhome

We're on our second camper with a macerator and black tank. The black tank CAN be emptied at regular dump points (or anywhere for that matter). It has 2 methods of emptying - pump out via a hose, or via gravity feed using the same hose (or decanting into a small tote for disposal if you're in one place for an extended period). I've not had to do that because we generally move on after a few days.
The pump's throughput is about 45 LPM, so it only takes 3-4 minutes to empty a full tank at a dump point.
I've had no problems with the system over several years of ownership, and get well over a week's use out of the black tank.

Sorry, my poor explanation.
If the dump point is further away than the length of your hose, you still need a cassette or other portable container to transfer the waste. That takes up space and partially defeats the benefit of the black tank.
The big advantage of a black tank is that the tank can be any size that will fit (and is within the weight limits when full) and can be remote from the toilet.
A vacuum toilet has similar advantages to the macerator.
Emptying 100L of liquid sewerage into a long drop or septic system may not be a good idea whereas you may be OK with 20L.

Another advantage of the composting toilet is the water savings.
Cheers,
Peter
OKA196 motorhome

Hi Glen,

I currently have an AOR Q+ with a macerator toilet (125L black tank) and the water recycle system (uses shower water to flush).

My prior AOR Q had the Dometic Vaccum toilet (~18L tank) .

With earlier camper trailers, I used a cassette type porta potti with a ~20L tank.

As I have a new AOR van on order, I too have gone through the exercise of evaluating all toilet types again. As I have yet to use a composting toilet, have done some research on them and discounted the idea.

Vacuum
Very good and very frugal on water, but small tank capacity. With 4 people you struggle to get through to the second day without emptying, 2 people you may make the 3rd day if conservative. No longer available new (spare parts getting harder to come by) so not a viable option with a new van.

Cassette
Cheap, especially the portable ones. Cannot empty into long drops no matter what the additive used is and shouldn't be buried into the ground if using the old blue formaldehyde fluid (which happens to be the best from a user perspective). Work well enough but far from a pleasant job to empty... don't do before a meal :)

Composting
Need to seperate the #1 from the #2 while in use, otherwise the "dry" waste gets too wet. Need to sit down for any use and cannot be used for oral excretions... not good if one is sick. Also requires a small fan to run 24/7 and the liquid container (#1's) need to be emptied daily. Solid waste needs to be emptied periodically (4-8 weeks) and cannot be emptied into waste disposal dump points (too dry)... burying or into the normal trash (yuk) seem to be common ways I have read about.

Macerator
Is arguably the best type around. Has no chemical additives and can be easily pumped into the common dump points and long drops. I carry camlock hoses and can easily reach over 15M if required, but have never needed more than the 5m hose in 4 years. A very easy and "clean" task compared to other options.

The size of the black tank dictates how often it needs emptying and my ~125L tank means I can go for 10 days (2 people) or stretch to over 14 days if #1's are minimised (night use only). When combined with the shower water recycle system like mine, there is no additional water use.

After having virtually all the different types and reading up on the composting, I am fitting the macerator again, though this time the "silent flush" version. This uses a seperate pump for the water in and waste out, unlike the combined pump on the standard macerator.

A hand pump option is available with the TMC macerator and friends who have it on their boat would have prefered it in their Q+. But the "silent flush" TMC overcomes the minor issues in the standard TMC macerator (keeps pumping water in even if outlet is blocked... think about it!).

Cheers

Peter, thank you very much for the clear explanation.
Sally,
publictoiletnearme.com

My impression of macerator toilets are that they're a very good system, esp combined with the grey water flush. I've had positive first-hand reports. But am I correct in saying that AOR are the only company that provides this option? If so then choosing that option limits you to one company, albeit a very good one.

I opted for a composting toilet in part for its simplicity. It's very hard for something to go wrong. Also for the length of time between emptying the composted waste, and the ease of doing so in a remote area. I think the Captain makes the emptying process seem worse than it is. If the solid waste has composted then it's not an unpleasant or difficult process. Nor is empyting the liquid waste, and the design of the unit makes the separation fairly automatic.

I think both systems are very good and a big improvement over a cassette. You pays your money and takes your choices.

We have been on the road for the past year with an Airhead Composting loo, I had to do a bit of re-engineering on it to get it working a bit better and would definitely go for another one rather than the current crop of dunnies.

But there is a new one on the market called the Separett Tiny and I would most definitely be going for one of those.

Separett Tiny

It has all of the advantages of a composting loo with none of the downsides. Mucking around with poo hoses and stinky cassettes is no way to spend a holiday.

Keith