I am putting a waterless in my detached shop, maybe master bath.

waterless.com

When you are off the grid and the well is 1100', you want to save all the water possible.

We are doing grey H2O as well.

Jim

Over the course of a lifetime, an average person flushes the toilet nearly 140,000 times. If you install a WaterSense HET, you can save 4,000 gallons per year and your children can each save about a third of a million gallons during their lifetime

I used a dual flush toilet in Europe a few years ago and thought it was so cool. I finally purchased a dual flush toilet from

www.macustrade.com.

I bought the Keewaydin (high back). So cool, works like a charm.

Just moved into our new house. Used 3 Toto Aquia upstairs and one Mansfield Eco Quantum downstairs - I personally like the Toto more. It is quieter and uses less water on liquid mode - but both work reasonably well.

When we finish the basement may try a waterless urinal -

I have to say that I don't understand "save water", at least not in areas where there is plenty of it available. It all just goes around and around and never disappears.

Saving on water or waste treatment makes a little more sense, although it many places, waste water that ends up in a river is many (like 100x) times cleaner than the river itself - that's right, flush your toilet more and the river gets cleaner.

jonr

I think it takes energy and carbon to process the water and pump it uphill to your home. Using less of it should lower your carbon print.

People with wells don't always have an unlimited supply of water. It is possible to run the wells dry, hopefully temporarily, under the right conditions. I assume that unnecessarily using more water also increases wear and tear on the well pump, pressure tank, and water softener, but I'm not positive. Reducing water usage should help. During times of drought, the water is still in existence, it's just somewhere else. Without rain to resupply the underground water supply, well water can be limited. I thought as you did when I lived in Philadelphia and had municipal water and the Delaware river nearby. Now that I'm in the country, I have a different perspective.

This will vary significantly with location.  MANY places are down hill of the natural reservoirs/aquifers, with minimal pumping & treatment required.  Many others are hauling it up 500 vertical feet and/or have extensive treatment requirements to make it potable.

In heating dominated climates water use adds a small but measurable heating load.  With 40-45F winter-water stagnating to a 65-70F in the bathroom, every old-skool 5 gallon flush is on the order of 1000 BTUs down the drain.  This loss too will vary with location.  (Wouldn't sweat THAT aspect in warmwater FL or SoCal, even on the coldest day of the year.)

Of course it's even more significant for showering & bathing, since you're looking at higher volume flows with even more heat added to get it to 105-115F, with more than 90% of the heat sent down the drain (unless you let the bath temper to room ambient before draining.)

In terms of where to spend the money for best return on carbon reduction, dual flush is way down there though. The difference between 0.9 gallon & 1.6 gallon flushes is under 150 BTUs in direct heat losses, and likely much less than that in pumping & treatment.  Even with a 30% efficiency coal-fired powerplant supplying those BTUs & running the pumps it's pretty miniscule.  You'll save more by cutting your shower time by a minute, or reducing it's flow by 5-10%

I had a poor 1.6 gpf toilet plug and overflow. The resulting $500 in damage wiped out the $ (and probably energy) savings for 50 years! So IMO, the most energy efficient plan is to simply buy the one that works best and hang on to it.

There are (or at least were) some pretty lousy low-volume toilets out there, and to go there for the energy savings alone would have ZERO return in any US market. Where water is precious it can be worthwhile, and where code demands it, well... (ya kinda hafta, eh?) Cheap toilets can be expensive- not worth the aggravation.

All the big players in the biz seem to be imitators of the original Toto siphon design (they were onto something!?!), and the average has improved greatly from a decade ago. I'm favorably impressed with the performance of the noo-improved version of the American Standard Cadet compared to earlier versions, (which isn't some delux model by any means), and my kid's a clog-creation EXPERT! :-) Most have gone to 3" tank flapper valves too.

Performance is tested & data maintained by the state of California- the condensed version, listed in order of performance (low to high) can be found here:

http://www.cuwcc.org/WorkArea/showcontent.aspx?id=12046

An important number to track is the column in the middle- grams of solids in a single flush. Anything over 500 is pretty good, over 750 is GREAT (that's almost 2lbs worth!) Less than 350, plan on flushing twice a lot...

I agree - my replacement is a Toto, chosen from that data.

From an energy standpoint, one might save as much as dual flush with dual bathroom fans - one for humidity (which can be saved in the winter, sent outside in the summer) and another smaller one tied into the toilet (never understood why this isn't standard). Both tied into HRVs.

It the house is tight enough to need active ventilation, you'll (almost) never want to "save" the humidity, even in winter.  (My house isn't all that tight, and the RH only drops below 30% indoors is when the high for the day is in single digits F.)

And if both fans are hooked up to HRVs, the difference between 1 vs. 2 is going to be even less than the energy loss difference between hi/lo volume flush.

Bathroom HRV under humidistat control are pretty effective, but the energy loss difference between HRV & exhaust-only fans under humidistat control is still pretty small in most of the lower 48.  Operating the ventilation with a parallel occupancy-sensor and humidistat control should be more than enough.

References indicate that low humidity is a problem in PassiveHouse designs (which use quite a bit of active ventilation).

http://www.passivhaustagung.de/Passive_House_E/ventilation_and_humidity.htm

"Conventional ventilation planners are inclined to specify rather high ventilation amounts for dwellings. There were times when 0.5-ach (or even 0,8-ach) was specified, precisely to keep the indoor humidity levels low during the winter in order to reduce the risk of condensation and mold."

Low humidity is only a problem in a PassiveHouse if they're being overventilated, and the prescription for solving that is to reduce the ventilation rate.  Without ventilation, humidity rises in a very tight house. One of the major indoor air quality issues that HRVs are addressing is that high indoor relative humidity.  Anything over ~65%RH  is becomes a mold-growth hazard.  For those with dust-mite allergies, anything over 50% increases that allergen risk.  Running the ventilation under humidistat control in winter is usually the right thing to do.

In summer overventilation will raise (not lower) the indoor RH in much of the eastern US.  (Take my house, f'rinstance, where dehumidification is ~15% of my annual power bill.)

Dry wintertime air is only an issue for houses with plenty of "natural ventilation", aka lots air leaks, the opposite of "tight".  The solution is to tighten up the house, not add humidity to the air.

But this has gone far afield of dual flush toilets, eh? ;-)

http://www.terrylove.com/crtoilet.htm

Some reviews on toilets.

Gonna plan on a urinal or two in the next house esp in entertaining area of home.   I'd do a little reading on the waterless ones though, I read about problems with them.

Our new house under construction will have the Caroma Caravelle 270 with its innards swapped for the Sydney model, which is Caroma's most efficient. Caroma rep said he would handle that. We may put a Walvit wall hung Caroma in the tight guest bath. In the master bathroom I'll have a urinal with a twist valve so that I can give it only as much water as I judge it needs. (Strong flush after eating asparagus; not so much if well hydrated.)

In Austin, Texas our mechanical engineer recommended bringing the fresh air (for an ICF wall, SIP roof house) in via a dehumidifying ventilator. He assesses moisture control as more important than ERV.

This would be true in most cooling dominated climates in the US east of the Pecos, and the latent AC loads exceed the sensible loads by quite a bit.  You can kill the sensible load with more insulation (and the peak sensible loads with thermal mass), but you're still stuck with removing the humidity, no way around it.  Humidity is much less of an issue in the cooling dominated parts of AZ/NM/UT/NV/CA than it is from eastern Texas to Maine.

Austin suffers from it's proximity to the gulf, where summertime humidity gets ridiculous at times.





In my low-sensible-load home in MA the latent load is pretty much ALL of it. We average only 350CDD, but average summer dew points are in the 60s, often into the 70s for days on end.  Dehumidification accounts for over 10% of my annual electricity use.

I remodeled my bath, the second I heard about dual flush toilets. It's eco-friendly and saves water! I couldn't resist. =)
The one I bought was a TB309 DUAL FLUSH ONE PIECE ULF ECO-FRIENDLY TOILET By EAGO _ I had to copy and paste..too long.
I go it from www.bluebath.com

I will also go to Blue Bath for my Kitchen.

I was working out of an office in Atlanta that had these.  They are made of a plastic that has a non-stick (ewww) coating on it/impregnanted into it.  When you......go........it hits that slippery surface & kicks back a mist or "pist".  The first couple times I used one, I walked out covered in it.  It was disgusting.  The solution was to stand about a foot back, with feet set wide around it.  Try explaining that one when someone walks in.  They may have their place, but I found them to be really gross.

Todd,

We purchased a Caroma Sydney Smart dual flush for our new house.  while it flushes well, the 'splash pool' (water level) is so low that we end up with solids smeared all over the bowl.  When we questioned the retailer who sold it to us, they replied that this is a problem with dual flush models in general.  We are pretty turned off to the dual flush concept now and are thinking of replacement it with a 1.28gallon single flush model like the Toto Drake.

I'm curious what others have experienced with their dual flush toilets?

Shawn

Shawn -

We do get a touch more smear I guess. My wife is pretty clean you know and she hasn't complained though. But the sides of out Toto are steep and most stuff slides off. I really haven't used the brush that much. Often times I use the small volume flush for a small stool and get away with it.

The Eco Quantum we have from Mansfield is also a dual flush Shawn but it has a high splash pool/water level. You might like this model better. I don't like it as much because it uses more water on the 'small flush' than our Toto and I can not really get away with the small flush for stool on the Eco Quantum - but with the higher water level on this one we never really get 'smearing' any more that with a conventional toilet.

I hope this helps. Overall I've been really happy to have both of them - its nice to teach our kids about the practical little things you can do to make a difference!

Todd