Post on 25-Dec-2014
description
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