[Greenbuilding] Toilets that Work: throttling flush volume on good performers

[Reuben Deumling]

I've just installed a Cadet 3 model toilet from American Standard, per
Lawrence's price sleuthing, and can report some early successes.

(1) the fill valve in the tank came preset to the lowest permissible flush
volume setting. I didn't change it. Default flush volume as installed:
1.25gallons.

(2) My local water authority gives away a device I'd never heard of called a
"fill cycle diverter." It is a tiny plastic manifold that goes on the end of
the flexible fill tube that diverts some of the refilling water directly
into the bowl through a vertical tube in the toilet tank. The one I got has
four ports. By directing three of them (3/4 of the water) destined for the
bowl into the tank, I saved an additional .25 gallons =1gpf.

(3) Next I rustled up a toilet dam, one of those flexible sheets of steel
coated in rubbery plastic that we used to jam into the toilet tank to keep
some of the water in the tank from whooshing through the trap valve when
flushing. The initial position I picked keeps a further 1/3 of a gallon out
of the flush.

So preliminarily I have achieved a 0.65 gpf toilet for $130 and some free or
quasi free toilet water-saving devices. I can't yet say whether I'll be
adjusting these parameters up or down, both are feasible with the two add-on
technologies I'm using, and in another few days I'll know more.

Adding these 2 conservation devices took all of 4 minutes. What took longer
was installing a water flow meter inline next to the toilet, so I can track
progress without running out to the city's water metre at my curb every time
I flush. :-)

Reuben Deumling


On 12/22/06, Reuben Deumling <9watts at gmail.com> wrote:
>
> Thanks for the in-store work on price & performance, Lawrence. Very
> helpful indeed.
>
> My question, which I've occasionally put to the folk who do this
> delightful testing over the past few years, is what the possibilities are
> of, for instance, taking the inexpensive Cadet 3 model you discovered and
> throttling the flush volume.
>
> Assuming the mechanics in the tank permitted this one should be able to
> buy and install one of these and then ratchet down the volume from the 1.6gpf level until it failed to perform adequately in normal use. In my view we
> should have considerable room to throttle in a 1,000 g model. I had hoped
> Bill Gauley et al. would try this, but so far no luck. Any thoughts? Any
> idea if the Cadet model tank innards would permit such experimentation? Or
> if not what the next cheapest high performance model is?
>
> Thanks.
>
> Reuben Deumling
>