The Flusher King: Testing Toilets

by Lloyd Alter, Toronto on 10.24.06
Design & Architecture (bathroom)

flusher.jpgWhen low-water flush toilets became the law, they were not very popular; people were even smuggling high-volume toilets across the border from Canada, because the things just didn't work, often requiring two or three flushes to get everything down. Engineer Bill Gauley of Veritec Consulting developed a test that has become the standard- The Maximum Performance (MaP) test. Starting with mashed potatoes and bananas to simulate you-know-what, Gauley's team searched for a "test specimen", and finally settled on soybean paste (miso) imported from Japan. This is expensive, since they keep flushing until the toilet doesn't work any more, so they started encasing the miso in a "thin latex membrane"- a condom. The testing is now almost universal, lessons have been learned, and six-litre toilets work better than the 13 litre ones they replace. The winner: the TOTO Drake, capable of handling 900 grams. (average male's maximum dump: 250 Grams). Now you have no excuse not to upgrade! ::The Star read ::test results here (big PDF)

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Comments (16)

Nice article Lloyd... what's more appealing than poo wrapped in a condom?

jump to top Anonymous says:

I've always wondered what the average male dump weighed but I've never been curious enough to crap on the bathroom scale.

jump to top doh says:

really? low water flush toilets are the law in the US? it seems to me it's hard to find any unless you dig around online for expensive, imported versions like the Toto you mention. Home Depot and the likes surely don't carry low-flush toilets.

jump to top CTP says:

While I am pleased that there are low flow toilets that actually work, please warn of impending poo pictures. Even if it is fake poo, it is not a pleasant sight with my morning cream-o-wheat.

jump to top Barbara Smith says:

I think all HD toilets are low flow. Low flow being around 1.6 gallons. And I think all new construction does need low flow.

jump to top Anonymous says:

The miso logs encased in latex are not appropriate fecal simulacra for testing low-water-volume toilets. While the pseudo-stools may effectively imitate floatational and dimension characteristics of the real thing, encasing them in latex prevents testing the toilets' ability to blast away inevitable streaks.

Why not just drop a chocolate cake in there?

Give me a high pressure airline toilet any day.

jump to top brennan says:

I like the American Standard Champion, I have one and it seems to use very little water per flush. It's secret is a large dump valve and trapway. On quick shot of water 2-3L and it clears a large amount. You can get 2 full and one part flushes per tank. The reason I found that out is we had a cat have a radioactive treatment and we had to flush the special litter. I was amazed at what one flush cleared. Even a large "dump" clears in one flush. When I redo the other bathroom I will install a champion in there too.

jump to top Tim says:

I recall reading an article that mentioned problems with low volume toilets further 'down the line' - i.e. there may be enough water to flush the loo itself, but not enough to carry the contents along old sewer systems. Anyone know if this happens much?

jump to top Beastie says:
I recall reading an article that mentioned problems with low volume toilets further 'down the line' - i.e. there may be enough water to flush the loo itself, but not enough to carry the contents along old sewer systems. Anyone know if this happens much?

I never have but then again I don't think my toilet is low flow. It works fine and I didn't feel like replacing it when I redid my bathroom. But it seems any other water would wash down the solids anyway, like from washing the hands. If the pipes to the sewer are small there is usually a solids pump, basically an in line blender so the tiny pipes do not get clogged.

jump to top Anonymous says:

Living in Germany makes me wonder if people test those toilets. I was always frightened by those 'shelf' toilets that just don't move the poo.


Then again, extensive travel through Tunisia taught me some lessons, too. Like why there was a long stick next to the 'toilet' (which was just a hole in the ground with no seat or anything). I guess I'm pretty satisfied with the US Toilets, then..

jump to top Mikey says:

OK, maybe I'm confused... maybe what I was looking for was the twin-flush system - super low-flush for #1 and heavier flush for #2. These are definitely widespread in Europe but not here.

jump to top CTP says:

You may need to check with a plumbing supply house rather than a home center like Home Depot or Lowes. You can get dual flush systems in North America and I think they are a great idea.

jump to top Tim Russell says:


Isn't the toilet paper a lot more likely to cause a clog than the poo?

jump to top Sfakko says:

My wife just got a new low-volume toilet and I'm convinced these are water wasters. Here is my reason:

A guest took a dump in it one evening and it took 4 flushes to get every bit down and there are still some "residue" floating at the bottom.

So if we had a toilet with a bigger tank, it may have taken only one or two flushes to get rid of this instead of over four.

So in retrospect, do these new low-volume toilets really save water? Yes if you want leftover crap sitting in the toilet.

jump to top Cody of the Environment says:

You should mention TwoFlush more often
It is a much cheeper way to conserve water and save money We all know about the $400.00 solution but what about the $50.00 solutions.
check www.twoflush.com and see for your self .
Thank you
Joe

jump to top Joe Molho says:

Regarding measuring toilet water consumption
It is not enough to just to measure the water going out of the tank . People (including experts)often forget to include the water that is replacing the water in the the siphon trap and the bowl via the small tube inserted into the overflow/fill tube.
The nature of my business directly involves toilet performance and efficiency so I have set-up a toilet testing station to measure exactly how much water is actualy being used per toilet per flush.
Toilets are mounted on a raised platform and the water is discharged directly into a measuring container.Our findings so far have been interesting.
I won't mention any brand names , but every 6 litre toilet I have tested so far uses between 8 and 9 litres per flush. It seems that the manufacturers performance numbers may be slightly optomistic.
Our side by side comparison tests in identical new fixtures also indicate that our vertical gate "dual flush" valve allows water to escape the tank considerably faster than the conventional hinge type flapper resulting in a faster more powerfull flush using less water.
The typical hinge style flapper by design seems to block the water flowing out of the tank and into the bowl conversely impeding the performance of the otherwise identical fixture.
This is the first side by side test comparison between the conventional hinged flapper design and the vertical gate design and the results for us have been consistant and conclusive.
Just thought you might be interested ,

Joe Brok

jump to top Joe Brok says:

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