Study on the Method of Connecting to the Gravity Drainage System of Bedside Flush Toilet

CIBW062 Symposium 2014

Study on the method of connecting to the gravity drainage system of Bedside Flush Toilet

K. MATSUSHITA (1), T. KUROKAWA (2), Y. OKUNO (3), M. OTSUKA (4) 1. [email protected] 2. [email protected] 3. [email protected] 4. [email protected] (1), (2) Universal Design Research Center, Research Institute, TOTO Ltd., Japan (3) Division of Faucets and Appliances Development, TOTO Ltd., Japan (4) Department of Architecture and Environmental Design, College of Architecture and Environmental Design, Kanto Gakuin University, Japan

Abstract

We screened the adequate connection ways of Bedside Flush Toilet (BFT) and the gravity drainage system after field research of introduction sites. The efficacy, safety and easy installation of BFT were evaluated by absentee interview. The characteristics of drainage and the impact of BFT upon the drainage system of BFT were measured in laboratory evaluation reproduced according to real housing. Elderly and those who require nursing care could use BFT owing to its user friendly operation. Some connection ways had sanitary hazard of seal destruction or overflow from water closet, but we found a number of connection ways that can avoid such problems. BFT could be used without troubles such as unusual odor, abnormal noise, water leakage and clogging of drain system in real housings and buildings.

Keywords

Nursing care, commode chair, flush toilet, bedside toilet, ADL

1 Introduction

TOTO had developed BFT after field trial for several years to reduce burden of excretion help in single dwelling houses and facilities for the elderly. Figure 1 shows outline of BFT and Table 1 shows its specifications. It was floor-standing toilet combined a tankless, one-piece toilet with intelligent seat, armrest, and crush-pumping unit on base plate. It had both of 2m of flexible water supply and drainage tube in

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hose cover for easy layout change of BFT after installation. Human waste and toilet paper are crushed to be passed screen of φ10 in crush-pumping unit and pumped into drain hose after the flush-button is pushed. The gravity drainage for conventional toilets must be connected to 75A or 100A of drain pipe with gradient of 1/pipe diameter. BFT is applied pumping drainage, so we can connect 20A drain without gradients within 8m. Table 1 shows the specifications of BFT. BFT can be arranged its position or direction according to the change of body situation of those who require nursing care. The smaller diameter drain pipe of 20A can make easy installation for remodeling of facilities and houses. This type of toilet is categorized as Pumping Toilet System by Center for Better Living of a nonprofit foundation (BL). BL has developed technical standards of Pumping Toilet Systems in 2013.

(1) Appearance

(2) Composition Figure 1 - Outline of Bedside Flush Toilet (BFT)

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Table 1 Specifications of BFT Category in BL Pumping Toilet Power source AC100V 50/60Hz Rated wattage 579W(50 Hz)/(60Hz) Dimension 610(W) ×1002(D)×746(H) Volume of Flushing Water 5.5 L/4.0L Weight 82 kg Peaknoise in operation 65 dB(A) Deodorant device Oxidation Catalyst Diameter of drainage tube 20A Pumpability 8m of VP20 within 8 elbows METI promoted the Project of the Development and Introduction of Robotic Devices for Nursing Care in FY2013–FY2017 to reduce expenses for nursing care; (1) Transfer aid device, (2) Mobility support device, (3) Excretion support device, (4) Monitoring devices for people with senile dementia, (5) Lifting aids, Mobility aids, (6) Toilet support, (7) Monitoring system for people with senile dementia and Bathing support.

2 Field research

We carried out field research of monitor sites. In addition, this experimental design had received ethical review of the Japanese Society for Wellbeing Science and Assistive Technology for the purpose of protection of the ethical of persons concerned.

2.1 Installed Condition

Table 2 shows the information of installed condition of representative monitors.

2.2 Recording of Excretion Behavior

The BFT in WT house was installed a data logger to record the clock time of seating, leaving and flushing. We could calculate sitting time on BFT and distinguish between his/her feces and urines by check type of the pressed flushing button.

2.3 Assay of Smell

The odor intensity of room with BFT in Shiigaoka Rakuraku-an was estimated after hydrogen sulfide, methyl mercaptan and ammonia of room atmosphere were analyzed by gas chromatograph.

2.4 Thoughts after using the BFT

We had interviews with monitors to confirm their thought about BFT.

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Table 2 Installation Sites of BFT (1) Facilities for the elderly Name Shiiga oka Rakuraku-an Satsuki-sou Category Multiple service station Facility for elderly -people Location Kitakyushu-City Setagaya -City Construction Method Wooden construction Reinforced concrete

Building Appearance

In stallation Objectives Empowerment of excretion Reducing the care burden

Installed Condition

Drainage of VP50 in space of 600 mm Descending 3.5m of VP20 and Outside Room under the double flooring 8.0m of VP40 at ground level

(2) Single Dwelling houses Name WT House FJ House

Installed Condition

Tatami Mat Location Chigasaki-City Kitakyushu -City Family Structure One of elderly female Two of aged couple Examinee Female, 80’s F emale, 60 ’s Certification Care level 2 Care level 3 In stallation Objectives Avoidance of conflict Reducing the care burden Drainage of Descending 0.3m of VP20 and Descending 0.6m of VP20 and Outside Room 12.5m of VP20 under ground 2.5m of VP20 under ground

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3 Experimental system

3.1 Actual p iping reproduction experiment

We reproduced the actual drain system of NS House in Sapporo -City. There were five members in NS family; the grandmother used BFT installed at a converted closet in her bed room. Figure 2 shows the drain system of NG House. P lumbing fixtures are gravity toilet, bathtub with washing floor, pan for washing machine , wash basin and BFT. Table 3 shows the outline of traps of each fixture. Figure 3 shows the experimental drain system reproduced according to that of NG House. The drain pipe of clear PVC pipe of 20A for BFT connected to private inverted manhole through vertical U -turn pipe. Two size of inverted manholes were used; 300A of NT House and 150A of current generation shown in Figure 4. We confirmed in advance that the seal water of BFT was secured within acceptable range owing to the effect of the pressure relief mechanism .

entrance

stairs steps existing gravity toilet

1500 550 500 600 additional BFT for old age 50A bath room 40A 20A bed room 50A 75A 75A 250 1100 800 250250 100A 100A 20A public manhole 450A private inverted manhole 300A 1380 800

Figure 2 - The drain system of NG House

Table 3 Outline of traps

Fixture Wash basin Washing floor Bathtub Gravity toilet

Appearance

Material brass PVC PVC china Depth of trap 100mm 50mm 50mm 50mm

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vertical U-turn drain pipe, PVC pipe 20A Bedside Flush Toilet(BFT) gravity toilet

PVC pipe 50A

PVC pipe 100A (1) Front view of the experimental drain system

S-trap of wash bowl pan for PVC pipe 50A bathtubinverted flexible tube of 2m of BFT A B D C PVC pipe 75A

PVC pipe 20A

unit ：［ mm］ (2) Plan view of the experimental drain system Figure 3 - The experimental drain system reproduced of NG House

(1) 150A Type (2) 300A Type Figure 4 - Dimensions of inverted manholes

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3.2 Measurement item s and methods

The m aximum/minimum pressure in drainage system was determined after the pressure fluctuation was measured by pressure sensors. The lost sealing water was measured by pulse-height analyzer . The height of water in drain pipe was measured by water level sensor . We judged acceptance and rejection of the pressure and trap depth using the standard of SHASE- S 218 -2008 “Testing Methods of Flow Capacity for Drainage System in Apartment Houses” ; the pressure within ±400Pa and the lost water seal to half depth of traps.

3.3 Condition of drainage loads

Table 4 shows the condition of drainage loads. We permitted drainage of single fixture and more than one fixture simultaneously. Gravity toilet was flushed with/without experimental waste substitutes . Table 5 shows the experimental waste substitutes. The drain of fixtures otherwise bathtub was started after the drain of bathtub reached the private inverted manhole to be confluen t in the system.

Table 4 Condition of drainage loads

R un number Gravity toilet BFT Bathtub 1 ○ Single- 2 ○ load 3 ○ 4 ○ ○ Multi- 5 ○ ○ load 6 ○ ○ 7 ○ ○ ○

Table 5 Experimental waste substitutes

Name of test Type of waste substitute Description ･Lay- flat toilet paper 6m (2 ply) -4 3 Lay-flat ･Volume 2.4 ×10 [m ] D’ 2 ply ･Mass 0.21 [kg] ･Real density 875 [kg/m 3]

4 Results and considerations

4.1 Results of field work

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4.1.1 Excretion behavior example of elderly Figure 5 shows an excretion behavior example of WT house identified by the memory of BFT. Her number of daily excretion was about three times larger than that of female students of Japan Women’s University according to 2012 report even though she was out for several hours a day. Meanwhile, her sitting period on toilet seemed to be longer than the average Japanese person. We found that sitting periods on BFT were sometimes over half hour or one hour in extreme case at other site. Also, the clock times in the excretions time had roughly punctuality in plural cases. Feb. 25, 2014

Feb. 26, 2014

Figure 5 - Example of excretion behavior example of elderly

4.1.2 Reasons of adoption of BFT Table 6 shows the reasons of adoption of BFT according to our hearing investigation to users who require nursing care, care personnel, curator of elderly facilities and plumbers after a period use for several months.

4.1.3 Usability Evaluation Table 7 shows the results of usability evaluation. We got many opinion and advice about BFT from persons concerned. According to results, BFT could cut down the physical and mental burden of staffs or caregiver. We heard no fatal problems about operation and installation of BFT in all sites. We predicted that BFT considerably cut down the cost of nursing care and medical treatment especially in case the home-care workers daily discard night soil in bucket of portable toilet at elderly home by housework support of the nursing-care insurance. 4.1.4 Results of odor analysis All families said, “We smell no fecal odor all of the time including evacuation time”.

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A lot of users said, “The exiting toilet had more ammonia odor than BFT”. BFT in bedroom were continuously used without any trouble concerned with odor through the year. Table 8 shows the results of odor analysis. Several odiferous substance was determined under the threshold perceivable level of odor intensity. This was due to the effect of oxidation catalyst in toilet seat without sprinkling of urine in standing pee.

Table 6 Reasons of Adoption of BFT

Persons Concerned Comments for Reasons of Adoption of BFT ”I only use BFT. I never use a portable toilet anymore!” User of those who ”I do not want to be seen my shit by familiar person.” Require Nursing Care ”There is no powers enough to go to the bathroom” ” It is too far to go to the bathroom without incontinence” “I want to reduce the burden of care.” Care Personnel “I want to change the position of the toilet to match the physical status of him/her.” “I want give him/her the opportunity to regain his/her confidence.” Curator of Elderly “We want to reduce the burden of care.” Facilities “We want to reduce fecal odor in facility.” “We challenge his/her potty training by rehabilitation with BFT.” “I cannot be achieved desirable arrangement with normal toilet.” Plumbers “I can realize the suitable drainage line far from existing drainage.” “Smaller drain with zero slopes save us several days of time.”

Table 7 Results of usability evaluation of BFT

Name Shiigaoka Rakuraku-an FJ House 1) All of 13 users only use 1) He shortened 40min a night BFT at night. of nursing for traveling her 2) The staffs could adjust the to toilet. position of BFT for each user 2) She improved shortness of to move him/her easily from breath in trip. Merits bed to toilet. 3) BFT was removed within 45 3) Urinary incontinence fairly min. before installation of an decreased. Three users could artificial breathing device. become free from diaper. 4) Physical and mental burden of staffs decreased. 1) Too heavy to be moved. 1) We are bothered by a feeling of Matters to be 2) Too many switches on its strangeness with naked toilet. decided remote for elderly. 2) We want device for hand- 3) It is difficult to layout from size. washing.

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Table 8 Results of odor analysis Result of Analysis Sampling Place Component Concentration Estimated Intensity H S 0.43 ppbv <1 Shiigaoka 2 CH SH <0.32 ppbv <1.6 Rakuraku-an 3 NH3 37 ppbv 0.0 H2S 0.34 ppbv <1 YN House CH 3SH <0.32 ppbv <1.6 NH3 31 ppbv 0.0

4. 1.5 Requirement of improvement about BFT We confirmed the following requirement for BFT: 1) Easier mobility by one female in case of cleaning or only nighttime use. 2) Wheelchairs must be accessible to elevating bed located next to BFT. 3) Foreign objects such as bandanna for bladder control pads or pre-moistened wipe for buttock cleaning must be taken out in a rapid manner if they were flushed. 4) Even smaller person under 150cm must feel his/her feet grounded firmly on the floor.

4.2 Drainage characteristic experiment

4.2.1 Behavior of traps of fixtures Figure 6 shows the maximum/minimum pressure of pressure fluctuation in experimental drainage system. Figure 7 shows the lost sealing water of traps of pan of washing machine and bathtub. The maximum/minimum pressures of pressure fluctuation in experimental drainage system were under criteria of SHASE-S218-2008 in all of drain loads. The experimental waste substitute had no effects upon the pressures or lost sealing water. The lost sealing water was under several millimeters in all of drain loads. Night soil from gravity toilet sometimes stopped in experimental drain system, but it was washed out by next flushing, while crashed and screened night soil from BFT was almost washed out after one flush.

30 30 Pmax Pmin Pmax Pmin 20 20 ］］

Pa 10 10 Pa ［［ 0 0

-10 -10 in drainage in drainage -20 -20 maximum/minimum pressure maximum/minimum pressure -30 -30 No.1 No.2 No.3 No.4 No.5 No.6 No.7 No.1 No.2 No.3 No.4 No.5 No.6 No.7 (1) Private inverted manhole, 150A (2) Private inverted manhole, 300A Figure 6 - The maximum/minimum pressure in experimental drainage system

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2 2 trap of pan of trap of pan of trap of pan of trap of pan of

］ 1.8 1.8

washing machine bathtub ］ washing machine bathtub 1.6 1.6 mm mm

［ 1.4 1.4 ［ 1.2 1.2 1 1 0.8 0.8 0.6 0.6 0.4 0.4 lost water sealing

0.2 lost water sealing 0.2 0 0 No.1 No.2 No.3 No.4 No.5 No.6 No.7 No.1 No.2 No.3 No.4 No.5 No.6 No.7 (1) Private inverted manhole, 150A (2) Private inverted manhole, 300A Figure 7 - The lost sealing water of traps of pans in experimental drainage system Finally, we found BFT had no adverse effect s on the experimental drainage system.

4.2.2 Connection methods of BFT to gravity drainage system Table 9 is the summary of our experimental results about connection methods of BFT of average flow rate 24L/min to gravity drainage. Connection to drainage under S -trap of wash basin without vent valve had risks of seal destruction burble . Vertical U -turn drain had no problems on pressure fluctuation and lost sealing water, but it had problem of wastewater leakage from rim of china of BFT in water stop failure of feed-water system. This wastewater leakage was no problems in gravity toilets because it is discharged in drainage pipe. Pressure fluctuation depended strongly upon the characteristics of pumping unit of BFT such as drainage profile. Large flow rate of BFT made large pressure fluctuation. In contrast, small flow rate of BFT may cause significant restriction of in continuous use.

Table 9 Tentative connection methods of BFT to gravity drainag e Gravity toilet Wash basin Floor Connection Header for Coupling Bare pipe Drainage Vertical U-turn drainage flange in WC under S-trap drain Timing of Plumbing In advance Concurrently Concurrently Concurrently Pressure Fluctuation ～～～～ of Drainage -230 +10Pa -6 +2Pa -960 +83Pa -40 +40Pa Lost Sealing Water 16mm 1mm 80mm 2mm

Diagrammatic Illustration

Sanitary Leak at trap or nothing nothing Odor reverse Risks U-turn drain Possibility ○ ○ × △

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Acknowledgements Development of BFT was adopted as one of the priority research projects Kitakyushu Foundation for the Advancement of Industry, Science and Technology (FAIS) from FY 2011 to 2012. This study was partly funded by METI under Project to Promote the Development and Introduction of Robotic Devices for Nursing Care .

Presentation of Authors Dr. Konosuke MATSUSHITA is a chief researcher of Universal Design Resea rch Center in Research Institute of TOTO Ltd. He got certifie d as Professional Engineer of m echanical engineering in 1994. His current research interests are the establishment of piping design approach for housings and facilities for the elderly to live in peace.

Tetsuya KUROKAWA is currently a senior research manager in the Fa ucet and Appliance Division of TOTO Ltd.

Yuichi OKUNO is a manager in the Faucet and Appliance Division of TOTO Ltd. He is a registered architect of the first class.

Dr. Masayuki OTSUKA is a Professor at Department of Architecture, Kanto- Gakuin University. He is a member of AIJ and SHASE. His current research interests are the performance of plumbing systems, drainage systems design with drainage piping systems for SI (Support and Infill) housing, the development of building energy simulation tool (BEST) and the performance evaluation of water saving plumbing systems.