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January 5th, 2009 8:47am PST

High Efficiency Toilets

Posted By Scott Nania 14 Comments

Toilets use more water in the home than any other appliance or fixture totaling approximately 30 percent of residential indoor water consumption. As a result of this usage, toilets often leak contributing to major water loss as well.

Designed for water conservation, high- efficiency toilets (HETs) have been defined by the plumbing industry and the Environmental Protection Agency (EPA) as those that use an average of 20 percent less water per flush than the industry standard of 1.6 gallons (or, 1.28 gallons). Using a high-efficiency unit (in place of 1.6 gallon flush units) can save up to 8,760 gallons of water each year for a family of four with average daily flushes of six each. In municipalities like Washington D.C., this roughly translates to a water/sewer usage annual savings of $50.00. Savings will be greater in climates were water is in shorter supply.
 
There are four (4) types of water efficient toilet systems currently available.

Gravity Fed Single- Flush Toilets
Gravity fed single- flush toilets operate the same way as any standard toilet, however, they use less total capacity per flush. Typical flush capacities that are available for these models are 1.1 and 1.28 gallons.

Dual-Flush Toilets
Designed for light and heavy flushes, dual-flush toilets tend to average less than 1.2 gallons per flush. They meet HET criteria of 1.28 gallons per flush or less (HET criteria for dual- flush toilets identifies the effective flush volume as the average of one high flush and two low flushes). Dual- flush models are available from many well-known manufacturers with light flush capacities from 0.8 to 1.1 gallons and heavy flush capacities from 1.3 to 1.6 gallons per flush. These toilets typically operate with a handle that can move up or down, or a two-button system. One direction or button will activate the lower flow flush, while the other will activate the higher flow flush.

Pressure Assist Toilets
Pressure assist, or pressurized tank, toilets are another high- performance, low-  consumption alternative. These toilets use either water line pressure or a device in the tank to create additional force from air pressure to flush the toilet. The device in the tank could either be a storage device with compressed air that would require replacement or a tank that creates pressure when the tank is being filled. These toilets typically average 1.1 to 1.2 gallons per flush. Some pressure assist systems move a greater volume of water at a significantly lesser volume of sound.

Power Assist Toilets
Power assist toilets operate using a pump to force water down at a higher velocity than gravity toilets. Power assist toilets require a 120-V power source to operate the small fractional horsepower pump. Typical flush volumes are between 1.0 and 1.3 gallons per flush and dual-flush models are also available.

Companies that produce these types of products, such as Niagara conservation , and the Chicago faucet company, will be exhibiting at the annual WaterEC conference.

All of these systems are strong alternatives that offer attractive cost savings and contribute to our conservation efforts. For additional information please search our archives at www.waterefficiency.net.

What Do You Think?

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Edo

January 7th, 2009 2:28 PM PT

If one removes the float attached to the flushing valve, the flapper opening can be tightly controlled by the flush lever. We have done this in our house and can flush urine with about 1 second, which is about a quart. This works on almost all toilets and thus one does not need to imediatly change out an old toilet for a low flush. The low flush is in how long one holds down the lever. Cheers-------Edo

doug201

January 13th, 2009 5:03 PM PT

I would say that your figures are flawed I also bought into them. I own an advanced wastewater treatment company and have participated in water conservation programs sponsored by our local utility company. Experts provided the same figures for toilet use as you did. This seem to be very good news for the gray water recovery systems. However: I did a survey of water usage records for several homes, picked at random from people I know and found average usage for a three bedroom home to be about 3-400 gpd. The University of Colorado did a study and found the average person across the U.S. uses 60 gpd. Using your figure of 30%, and an average of 350 gpd usage per home, I am being told that 30% of 350 = 105 gpd is used for toilet flushing. This equates to 105/1.28 per flush = 82 flushes per day. I would suggest that someone needs to see a doctor. But you were suckered. You believed the pie chart. Almost all states use empirical data that was collected in the 1960's or '70's. This was prior to the advent of low flow fixtures, low usage washers, and low flow toilets. If you use flows (5 gallon toilet flushes) from that time (60's-70's) period, your data is correct. Unfortunately, no one seems to think it might be time to update the facts. It is easier to just go along with what has always been, and I am not referring to you. You just accepted what is accepted practice. Doug Sharp

g harley

January 13th, 2009 5:48 PM PT

You cannot get any greener or more water efficient than an absolutely NO water toilet. Check out swsloo.com, no water, no chemicals, & NOT a composter. Low maintenance and no odor.

Steve E-S

August 26th, 2009 8:52 AM PT

I often find that folks confuse indoor use and total residential use when comparing across cities. Or even worse, comparing gross per capita (total system use divided by served population) with residential per capita (total residential use divided by served population). Much of the data on residential water use patterns quoted by EPA, states and others comes from a very substantial study undertaken by the Water Research Foundation (formerly AwwaRF) about 10 years ago titled Residential End Uses of Water. It analyzed water use in about 1200 homes using a data logger to determine how much water each fixture used. Very data intensive and lots of information to mine on all sorts of topics. It did include a look at low flow fixtures. Toilet use represented about 27% of total INDOOR use. While it is almost 10 years old and probably due for an update, it is still the best source for detailed info on how water is used in the home. Summary information about the report can be accessed at the Research Foundation web site at http://www.waterresearchfoundation.org/research/TopicsAndProjects/execSum/241.asp. Members of the Foundation can download the report for free. Otherwise, you could purchase a copy at the AWWA Bookstore at awwa.org

pfmpfm

September 16th, 2009 8:53 AM PT

Figures don't lie, but liars figure. - Samuel Clemens (alias Mark Twain). If your experiment needs statistics, you ought to have done a better experiment ... I have for the last 30 plus years been active in the design, installation, operation and maintenance of a myriad of forms of residential on-site wastewater treatment and effluent disposal systems and I too conclude the savings our industry alludes will be achieved with installation of newer low-flow commodes and devices is extremely flawed. We need better data to enable us to provide full, open, honest, timely disclosure to everyone on where and how our water is utilized.

greg chick

September 16th, 2009 8:58 AM PT

industry professionals need to use "facts" honestly, not just spin data. Anti oponets of the efforts use such "propaganda" as just that! tating "stats" or "facts" extracted from a certain view is WRONG. Did you know that one could use the water meter reading and suggest it reflects household use!,IT DOES NOT. Water meters attempt to meter the water that goes thru them, INCLUDING the approx. 50% that is spent before the house on the yard! Right off the bat here is an oppertuinity to SPIN. Regional diffrences effect this outdoor % signifigantly.

AWE.ful

September 23rd, 2009 8:57 AM PT

First of all, the 30% figure that is in the original posting by Mr. Omelas is fairly accurate because it is a percentage of INDOOR water use in a single family home. In that SF home, approx 50% is outdoor and 50% is indoor. Toilets are shown as about 14% of the TOTAL. I believe that these numbers are based upon the 10 year old residential end use study by Aquacraft for AWWARF (as mentioned in a previous posting). Here we are, 10 years later, and the toilet usage percentage could be higher or lower! That's because along with efficiencies in toilets, other indoor uses are experiencing efficiencies as well. So, today, we really don't know where the numbers stand with respect to new housing. Hopefully, work now underway by Aquacraft will disclose that. Mr. Omelas failed to mention a FIFTH type of HET, that of the flushometer valve/bowl combination. These are far far more prevalent than the "power assist" he talks about!!

Sfisher

September 29th, 2009 1:07 PM PT

I am seeking guidance regarding a new product/technology for the away-from-home washroom. I am a director of Advanced Modern Technologies Corporation, a California corporation ("AMTC") (www.amtcorporation.com). AMTC is a leading global designer, manufacturer and distributor of innovative and reliable water saving products for the away from home washroom. AMTC has a technology today that can cost effectively save billions of gallons of water each year. AMTC's manual and automated flush retrofit systems provide a low cost solution to efficiently convert the existing installed base of urinal and toilet fixtures to the high-efficiency standards (without the necessity of changing the porcelain). AMTC's replacement flush handles cost approximately $50-$60 dollars, can be installed in one minute by a non-plumbing professional and have a payback of 6-12 months. I have been assisting the company in building awareness with various federal government agencies as I believe that the Federal Government has an important role to play in the adoption of this important technology. This has been slow going! I would appreciate any insight that anyone may have into how we could accelerate penetration with the Federal Government. I am aware of Executive Order 13423 as well as the various Energy Policy Acts. Thank you in advance. Stephen Fisher sfisher@hudsonferry.com

greg chick

October 21st, 2009 7:43 AM PT

Mr. Fisher I am not a fan of the politicians, I dont even think they are your target. I.A.P.M.O. is, and they are a fantastic org. I call them an AHJ, and have you got listing with them? Greg Chick, greg@ramonasplumber.com

sfisher

October 21st, 2009 8:58 AM PT

Greg, All of AMTC's plumbing devices have been tested by IAPMO. Stephen

water conservation

October 22nd, 2009 12:08 PM PT

I think it's great that you have included HET's as an important topic of water conservation. However, I believe the numbers shown for gallons saved is inaccurate. You stated: "Using a high-efficiency unit (in place of 1.6 gallon flush units) can save up to 8,760 gallons of water each year for a family of four with average daily flushes of six each." The savings is actually 2,803.20 gallons per year. If you take the gallons saved with the difference in the toilet which is .32 then multiply by 6 (flushes per day) = 1.92. Then multipy 1.92 by the four people in household = 7.68. Finally multiply 7.68 by days of the year 365 = 2803.20. It looks like you just took 4 (# in household) X 6 (avg flushes per day) then multiplied by 365 days, which equals your total of 8,760 gallons.

raindrops

October 22nd, 2009 7:28 PM PT

Some good info but don't overlook rainwater harvesting. Raindrops Cisterns feels that there is no better water conservation than collecting rain water. It not only saves water but reduces storm water. Raindropscisterns.com

ModelAPic

February 10th, 2010 8:48 AM PT

The discussion on "High Efficiency Toilets" has possibly skewed away to High Efficiency Water use. A majority of these devices are not capable of doing their intended task in a single flush. So, the "task" requires 2-3 flushes to get the job done, hence 2.6 or 3.9 gallons per valid flushing, etc. These numbers jive with the observations of water use from several managers in this discussion. So, the real problem is still how to dispose of your presto-log quickly and efficiently, and try to conserve water in the process. The idea of an out-house has actually addressed both of these problems for quite some time now......

rljohnsufl

March 4th, 2010 6:38 AM PT

I'm surprised that this discussion does not cover ecological sanitation. Composting toilets often use NO water and eliminate the need for expensive and energy intensive sewer infrastrucure. They don't smell, and at the end you have rich fertilizer that is safe to use as a soil amendment. Even urine recovery (with the #2 still going to a treatment plant) would be better than what we have today. Urine is rich in both nitrogen and phosphorus, nutrients that we currently mine from the earth. Recovered urine can be made into struvite, a mineral that is a great fertilizer. Our "humanure" is a resource, not waste.

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