1.6 ULF to 1.28 HET upgrade concerns

March 1, 2010
concerns regarding the upgrade from ULF (1.6-gpf toilets) to HET (high-efficiency 1.28-gpf toilets)

Mike, a plumbing engineer, writes, "Hello Mr. Yates. I’ve been commissioned to perform water-efficiency audits at several facilities in the area, which is to include recommendations for toilet and urinal replacement/retrofits. Most of these facilities are currently equipped with 1.0-gpf urinals and 1.6-gpf toilets. I feel pretty good about recommending they replace all 1.0-gpf urinals with 1-pint models, but I am having a tough time with the toilets. I have been doing extensive research online the past few days, which led me to your article "The 1.28-gpf limbo: how low can we go?" The building owners are convinced they want to upgrade their 1.6-gpf toilets. I’ve been reading that the 1.28-gpf toilets often require two to three flushes and on average use 25% more water than the dual-flush models. Your article leads me to believe that this technology is improving and perhaps they should wait it out. I’m hoping for your two cents as to what to recommend. I’ve also thought about perhaps recommending the dual flush conversion in womens rooms only."

As it turned out, our PE friend had two main concerns regarding the upgrade from ULF (1.6-gpf toilets) to HET (high-efficiency 1.28-gpf toilets): flushing performance and drain line carry as outlined in an online article at: www.cuwcc.org/WorkArea/downloadasset.aspx?id=11474.

D-Day: Jan. 1, 1994
This is the day manufacturers had to stop making toilets using more than 1.6-gpf. Anyone, plumbing contractors in particular, who suffered through the 1.6-gpf nightmare following the mandated reduction in flush-volume from 3.5-gpf to 1.6-gpf can certainly relate to Mike’s concerns regarding flushing performance – especially if he goes out on a limb by endorsing the use of 1.28-gpf models. But you and I did live through the 1.6-gpf debacle, which was brought on by decades of "if it doesn’t flush well add more power." "Power" was delivered by utilizing more water – something we can no longer do because of our awareness that using 30% to 40% of our potable water resources to flush is, to put it bluntly, is an asinine waste of a precious resource. Once burned (repeatedly) by products that don’t perform as advertised, it’s tough to go back where the hot blast of customers’ wrath that seared our flesh might once again burn with the intensity of the sun’s core! But, we’re way past those poor-performing 1.6-gpf models and it’s been years since we’ve had to face complaints about multiple flushes and frequent clogs.

Shortly after 1.6-gpf toilets were mandated, we installed multiple half-baths in a commercial strip-mall, and the township plumbing inspector required each store be served by a separate 6-in. sanitary sewer line and that included a 6-in. house trap for each half bath. I was convinced connecting a 1.6-gpf toilet and lavatory bowl to run through a 6-in. house trap would turn into a clog-of-the-week, call-back nightmare scenario. I was wrong. The stores have been clog free for more than a decade. Subsequent visits and checkups have revealed no buildup in the traps or the lines.

Performance of 1.28-gpf HET
Don’t shoot the messenger, but based solely on my own experience there have been no issues with these high-efficiency toilets, all models are gravity-flush utilized in three different locations.

Residential: Our home has several HET toilets that have been in use for more than six months and we do not need to flush more than once to clear the contents. In fact, they flush better than did our 3.5-gpf or, for that matter, the newer generation of 1.6-gpf models. The run from farthest 1.28-gpf toilet to the street is more than 400-ft. of 4-in. cast iron piping and the line has a 4-in. house trap (required by code, but I’d have one even if not required).

Rental Property: A vacation shore rental property, with two full baths and three bedrooms, has two 1.28-gpf toilets, two 1.0 GPM lavatory faucets, two 2.5 GPM scald-guard shower faucets and one 2.0 GPM kitchen sink faucet, and has not seen one clog. Given the fact that virtually everyone uses the outdoor shower (not connected to the sewer line) for bathing during summer rental season, I’d suggest this qualifies as more commercial than residential. From the farthest toilet to the septic tank, it’s a 120-ft. run of 4-in. plastic piping.

Commercial: York County Nixon Park, where we recently converted the public restrooms to comply with WaterSense guidelines as part of its overall educational center’s focus on use of the purified/filtered potable water, has also had no problems with high-efficiency toilets. A mural depicting York County’s watershed greets more than 5,000 school children who tour this facility each year and the incoming potable water line runs exposed here with a water meter that can be reset as visiting groups begin their tour. The public restrooms are adjacent to the mural and have five 1.28-gpf toilets, four self-powered infrared 0.5 GPM lavatory faucets, and one 0.5-gpf self-powered infrared urinal flush valve. (The self-powered devices incorporate a miniature turbine in-line to generate electricity that recharges their batteries.) Distance from restrooms to septic system exceeds 150-ft. of 4-in. drain line – no house trap. Additional information about the York County Nixon Park is available at: www.yorkcountyparks.org/parkpages/Nixon.htm.

Next month’s column will focus on drain line carry.

Dave Yates owns F.W. Behler, a contracting company in York, Pa. He can be reached by phone at 717/843-4920 or by e-mail at [email protected].

All Dave Yates material in print and on Contractor's Web site is protected by Copyright 2009. Any reuse of this material (print or electronic) must first have the expressed written permission of Dave Yates and Contractor magazine. Please contact via email at: [email protected].

About the Author

Dave Yates

Dave Yates material in print and on Contractor’s Website is protected by Copyright 2017. Any reuse of this material (print or electronic) must first have the expressed written permission of Dave Yates and Contractor magazine.

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