hydrosense for water management scientists

design:use:build: ubicomp lab

university of washingtonuniversity of washington

Eric LarsonMSEE, PhD CandidateUniversity of WashingtonACEEE Hot Water ForumMay 13, 2010

water tower

thermal expansion

tank

hosespigot

hot water heater

kitchen

water efficiency starts in the home

bathroom 1

bathroom 2

water tower

thermal expansion

tank

laundry

hosespigot

hot water heater

kitchen

dishwasher

bathroom 1

22%

what about wherewater goes?

11%

bathroom 2

how tovalve level

disaggregation

easy to install

low-cost

reliable

sense?

typical water meters

- only provide aggregate information on water usage

- require pipe modification for installation

AMR

water meters?

hydrosensewhat about pressure?

thermal expansion

tank

laundry

hosespigot

hot water heater

dishwasher

hydrosense

kitchen sink kitchen sink

(hot)(cold)

toilet

raw bathroom sink signal

stabilized pressure drop

openvalve

closevalve

time (t)

water tower

incoming cold water from supply line

thermal expansion

tank

laundry

bathroom 1hose

spigot

bathroom 2

kitchen

dishwasher

pressure regulator

hot water heater

some possible installation points

validationten locations

- 8 houses- 1 apt / 1 cabin

size- avg: 2,300 sq ft- min: 750 sq ft- max: 4,000 sq

ftinstall point:

- 8 hose bib- 1 water heater- 1 utility faucet

- ten locations- 706 trials- 84 total fixtures

Sinks Toilets Showers Bathtubs Clothes Washer

Dishwasher0%

20%

40%

60%

80%

100%98

%

99%

96%

100%

100%

100%

95%

98%

89% 10

0%

100%

Open Events Close Events

fixture classification results

individual fixture classification96.4%

individual valve classification94.1%

fixture classification results across homes

H1 (12 valves)

H2 (8 valves)

H3 (6 valves)

H4 (5 valves)

H5 (9 valves)

H6 (8 valves)

H7 (8 valves)

H8 (6 valves)

H9 (7 valves)

H10 (7 valves)

Aggregate Overall

0%

20%

40%

60%

80%

100% 98.9% 97.9%96.8%

Open Events Close Events

who values from disaggregated water?

homeowners

utilities

appliance manufacturers

commercial businesses

disaggregated usage: utilities and homeowners

tiered pricing: utilities

by fi

xtur

e

by time

leaks?

manufacturers and policy makers:

end use efficiency

water conscious practices: business

1995 USGS

continuing workapartment buildings

longitudinal evaluation

battery-less

un-calibrated flow

longitudinal data collection

future workreduced fixture

calibration

disaggregate outdoor usage

commercial buildings

leaks

design:use:build: ubicomp lab

university of washingtonuniversity of washington

Thank You!

facu

lty

stud

ents

http://ubicomplab.cs.washington.edu

Marilyn OstergrenShwetakPatel

James FogartyJon FroehlichTim CampbellEric Larson Les Atlas

eric.cooper.larson@gmail.com

backup slides

Ground Truth

Ground Truth

•Need for reliable ground truth under naturalistic usage patterns

•Challenges• Many different styles of faucet, showers, dual/single handle, toilets,

clothes washers, dishwashers• Hot/Cold must be disambiguated• Wireless network

using ∆pressure to estimate flow

r

L

pipe

𝑄= ∆𝑃 𝜋 𝑟4 8 𝜇 𝐿 ≡ ∆𝑃 𝑅𝑓 poiseuille’s law:

𝑅𝑓 = ∆𝑃𝑄 ≡ 8 𝜇 𝐿𝜋 𝑟4 fluid resistance formula:

∆P = change in pressureL = length of piper = radius of pipeμ = viscosity of liquidQ = volumetric flow rate

using ∆pressure to estimate flow

r

L

pipe

∆P = change in pressureL = length of piper = radius of pipeμ = viscosity of liquidQ = volumetric flow rate𝑄= ∆𝑃 𝑅𝑓

water tower

incoming cold water from supply line

thermal expansion

tank

laundry

bathroom 1hose

spigot

hot water heater bathroom

2

kitchen

dishwasher

pressure regulator

acquiring Rf

𝑅𝑓 = ∆𝑃 𝑄 𝑄= ∆𝑃 𝑅𝑓

flow estimation results

HomeAvg Error

(GPM)Stdev Error

(GPM)Avg Error

(%)Stdev

Error (%)H1

(7 valves)0.17 0.13 7.3 6.7

H4 (6 valves)

0.19 0.17 5.6 5.3

H5 (8 valves)

0.13 0.11 4.5 5.5

H7 (8 valves)

0.67 1.47 22.2 46.0

flow estimation results

HomeAvg Error

(GPM)Stdev Error

(GPM)Avg Error

(%)Stdev

Error (%)H1

(7 valves)0.17 0.13 7.3 6.7

H4 (6 valves)

0.19 0.17 5.6 5.3

H5 (8 valves)

0.13 0.11 4.5 5.5

H7 (4 valves)

0.15 0.18 4.5 3.8

0

0.5

1

1.5

2

2.5

H1 H4H5 H7

Number of Samples

Aver

age

Erro

r (G

PM)

flow estimation using interpolated Rf

After 5 Rf samples, average error is 0.27 GPM

future work: hydrosense 2.0