Industrial Ecology – Spring 2012
MR. COFFEE – REDESIGN AND
CONCLUSIONS
1
Table of Contents
• Recap – Disassembly & Analysis
Conclusions
• Redesign – Use Phase and Additional
Improvements
• Conclusions – Total Impact Reduction
Recap
Redesign
Conclusions
2
Disassembly- Explosion Diagram
http://www.buyspares.co.uk/tefal/coffee-makers/896115-vitesse-coffee-maker/catalogue.pl?shop=tefal&path=290047&model_ref=41271&illustration_ref=27443
Recap
Redesign
Conclusions
3
Eco Audit- Energy Summary
Phase
Material
Manufacture
Transport
Use
Disposal
Total (for first life)
End of life potential
Energy (MJ)
139
30.4
3.87
2.77e+03
1.3
2.94e+03
-33.3
Energy (%)
4.7
1.0
0.1
94.1
0.0
100
CO2 (kg)
6.43
2.31
0.275
167
0.0912
176
0.968
CO2 (%)
3.7
1.3
0.2
94.8
0.1
100
• Carbon and Energy Totals
Recap
Redesign
Conclusions
4
Eco Audit- Water Consumption Summary
Materials, Manufacturing, End of Life
(.5%)
USE
(99.5%)
Recap
Redesign
Conclusions
5
Problem Statement – Where we left off
Identify
• 14 Million Coffee Makers are sold each year in the United States
(consumer watch)
• Consumer coffee makers require energy to compensate for heat
loss.
• Reduce Energy Consumption during use through redesign
• Aim to move to insular materials to reduce waste heat
Hypothesize • Reduce energy consumption through behavioral change
• Energy conservation by changing key components: Pot,
Conductive plate and Heating element
• Propose Use Based conservation– How many cups do you drink
Implement compared to your waste?
Recap
Redesign
Conclusions
6
Function, Objectives, Constraints, Free
Variables
Function
• Provide at home fast, easy, cost efficient coffee
Objective
• Produce hot water at appropriate temperature for coffee brewing
Constraints
• Water Resistance, heat resistance, stiffness, capacity
Free Variables
• Heating time, material choice, material thickness
Recap
Redesign
Conclusions
Redesign – Design Requirements
Component
Function
Objective
Constraints
Free Variables
Packaging
Protection/Marketing
Minimize Eco- Impact
Load < Damaging
Load
Material Choice,
Thickness
Polypropylene Shell
Structure & Support
Minimize Eco- Impact
and maintain cost
Stiff and Strong
Enough, Cost
Material Choice,
Thickness
Electronics
Controls machine
operation
Minimize Eco- Impact
Simple Coffee
Controls
N/A
Filter Basket
Hold Coffee Grinds
Minimize Eco- Impact
Stiff and Strong
Enough, Cost
Material Choice,
Thickness
Coffee Pot
Contain and
Insulate Coffee
Reduce Thermal
Losses
Contain 8 Cups,
Hold Liquid
Material Choice,
Thickness
Heating Element
& Tubing
Heat the water
Reduce Thermal
Losses
Electric –
Thermal
Conversion
Material Choice,
Thickness
Recap
Redesign
Conclusions
Redesign – Coffee Pot Materials Selection
Recap
Redesign
Conclusions
Redesign – Analysis of Polypropylene
Recap
Redesign
Conclusions
Redesign – Analysis of Polypropylene
Recap
Redesign
Conclusions
Use Phase – Key Design
Changes
•
•
•
•
Insulated Coffee Carafe
Heating Element Location
Stainless Steel Reusable Filter
8-cup Water Capacity
Recap
Redesign
Conclusions
Redesign: Insulating Carafe
• Dual shell vacuum
insulation.
• Minimal points of
contact.
• Minimal heat loss by
conduction.
• Keeps coffee warm at
160F (71C) for up to 6
hours.
• No need for reheating of
coffee
Recap
Redesign
Conclusions
Redesign: Result of Insulating Carafe
• Heat transfer by conduction.
• Heat transfer is minimized by the
coefficient of thermal
conductivity of insular material.
• Heat transfer is minimized by the
insulation thickness.
Energy Calculations.
- Input at 900watts
-10min/day on time
Energy = 900J/s*600s=540kJ/day
Life time energy saving
2770MJ-1182.6MJ=1587MJ
57% cut in energy consumption
Recap
- Life time = 6yrs
Energy = 540kJ/day*365day*6years
=1182.6MJ/lifetime
Redesign
Conclusions
Usage Adjustments – Reusable
Filters
Energy CO2
(MJ) (kg)
Total Before
End of Life
Total After
End of Life
Total
Stainless Steel
Reusable Filter
Paper Filters
7.7
0.5
2.0
0.2
336.3
7.7
Saves up to 334.3 MJ of energy and 7.5kg of CO2
Recap
Redesign
Conclusions
Usage Adjustments – Reduction
in Water Capacity
Original Use Water Consumption: 93,220kg
New Water Consumption:
• By reducing capacity to 8 cups, an estimated
reduction in daily use is 2 cups
Total Use = 74,661kg
Water Savings: 18,559kg
Recap
Redesign
Conclusions
Redesign – Analysis & Redesign of Packaging
Materials
Energy (MJ) in Packaging Materials
14
12
10
8
6
4
2
0
Original
PLA
Material
Plastic Bag
1.7MJ
Original Styrofoam
10MJ
Original Total
11.7MJ
New PLA
1.546MJ
Energy Savings
Recap
Redesign
Manufacturing
0.13 MJ
0.66 MJ
0.79MJ
0.18MJ
Conclusions
Total (MJ)
12.49
1.726
10.76
Redesign – Eliminating water transport in Use
phase
Assumptions:
• The entire reservoir,8 cups is transported through
the machine in approximately 10 minutes
• The Coffee is warmed to 90.5-96C (Environmental
impacts of different methods of coffee preparation
by Eva Brommer,Britta Stratmann and Dietlinde
Quack)
• Energy losses can be directly correlated to energy
savings.
• Room temperature is 23 degrees Celsius.
• The tubing is a perfect cylinder of length .3556
meters
• Coefficient of Thermal Conductivity of the Tubing is
.13 W/mK
(http://www.engineeringtoolbox.com/thermalconductivity-d_429.html)
Recap
Redesign
Conclusions
Redesign – Calculating Energy Gains
𝑡𝑖 − 𝑡𝑜
𝑞 = 2𝜋𝑘
𝑙𝑛(𝑟𝑜 / 𝑟𝑖)
𝑞
= ℎ𝑒𝑎𝑡 𝑡𝑟𝑎𝑛𝑠𝑓𝑒𝑟𝑟𝑒𝑑 𝑝𝑒𝑟 𝑢𝑛𝑖𝑡 𝑡𝑖𝑚𝑒 𝑝𝑒𝑟 𝑢𝑛𝑖𝑡 𝑙𝑒𝑛𝑔𝑡ℎ 𝑜𝑓 𝑐𝑦𝑙𝑖𝑛𝑑𝑒𝑟 𝑜𝑟 𝑝𝑖𝑝𝑒 (𝑊/𝑚, 𝐵𝑡𝑢
/ℎ𝑟 𝑓𝑡)
𝑘
= 𝑇ℎ𝑒𝑟𝑚𝑎𝑙 𝐶𝑜𝑛𝑑𝑢𝑐𝑡𝑖𝑣𝑖𝑡𝑦 𝑜𝑓 𝑡ℎ𝑒 𝑀𝑎𝑡𝑒𝑟𝑖𝑎𝑙 (𝑊/𝑚. 𝐾 𝑜𝑟 𝑊/𝑚 𝑜𝐶, 𝐵𝑡𝑢/(ℎ𝑟 𝑜𝐹 𝑓𝑡2/𝑓𝑡))
𝑡𝑜 = 𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 𝑜𝑢𝑡𝑠𝑖𝑑𝑒 𝑝𝑖𝑝𝑒 𝑜𝑟 𝑐𝑦𝑙𝑖𝑛𝑑𝑒𝑟 (𝐾 𝑜𝑟 𝑜𝐶, 𝑜𝐹)
𝑡𝑖 = 𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 𝑖𝑛𝑠𝑖𝑑𝑒 𝑝𝑖𝑝𝑒 𝑜𝑟 𝑐𝑦𝑙𝑖𝑛𝑑𝑒𝑟 (𝐾 𝑜𝑟 𝑜𝐶, 𝑜𝐹)
𝑙𝑛 = 𝑡ℎ𝑒 𝑛𝑎𝑡𝑢𝑟𝑎𝑙 𝑙𝑜𝑔𝑎𝑟𝑖𝑡ℎ𝑚
𝑟𝑜 = 𝑐𝑦𝑙𝑖𝑛𝑑𝑒𝑟 𝑜𝑟 𝑝𝑖𝑝𝑒 𝑜𝑢𝑡𝑠𝑖𝑑𝑒 𝑟𝑎𝑑𝑖𝑢𝑠 (𝑚, 𝑓𝑡)
𝑟𝑖 = 𝑐𝑦𝑙𝑖𝑛𝑑𝑒𝑟 𝑜𝑟 𝑝𝑖𝑝𝑒 𝑖𝑛𝑠𝑖𝑑𝑒 𝑟𝑎𝑑𝑖𝑢𝑠(𝑚, 𝑓𝑡)
Recap
Redesign
Conclusions
Redesign – Calculating Energy Gains
Temperature©
Q (W/m)
Energy Lost
Per Year
Per Life Cycle
90.5
-40.248731
-8587.469264
-3.1344263
-18.80655769
91
-40.384441
-8616.424283
-3.1449949
-18.86996918
91.5
-40.519953
-8645.337254
-3.1555481
-18.93328859
92
-40.65527
-8674.208508
-3.1660861
-18.99651663
92.5
-40.790394
-8703.038368
-3.176609
-19.05965403
93
-40.925324
-8731.827154
-3.1871169
-19.12270147
93.5
-41.060064
-8760.575181
-3.1976099
-19.18565965
94
-41.194614
-8789.282762
-3.2080882
-19.24852925
94.5
-41.328975
-8817.950204
-3.2185518
-19.31131095
95
-41.463151
-8846.57781
-3.2290009
-19.3740054
95.5
-41.59714
-8875.16588
-3.2394355
-19.43661328
96
-41.730946
-8903.714709
-3.2498559
-19.49913521
Recap
Saves Approximately 18 MJ
Per Unit
35
30
25
20
15
10
5
0
Disposal Phase
Eliminating Water
Transport
Transportation Phase
Manufacturing Phase
Redesign
Conclusions
Redesign:
Recap
Redesign
Conclusions
Redesign: Water & Heating Diagram
Recap
Redesign
Conclusions
Redesign: Filter & Basket
Recap
Redesign
Conclusions
Redesign: Cumulative Results
Improvement
CO2 Reduction
(kg)
Energy
Reduction
(MJ)
Water
Consumption
(kg)
Insulated Pot
85
1587
N/A
Packaging
Materials
.35
10.76
12
Reduction of
Water Capacity
N/A
N/A
18559
Relocation of
Heating Element
N/A
18
N/A
Recap
Redesign
Conclusions
Conclusions- Overall Impact
120%
Summary of Reductions Through Redesign
100%
21%
80%
53%
66%
60%
40%
20%
0%
Water Reduction (kg)
CO2 Reduction (kg)
Recap
Redesign
Conclusions
Energy Reduction (MJ)
Conclusion
Comparability:
• Costs – New Design is in the same price bracket as original
• End-of-Life – Both glass and stainless steel can be recycled
Significant Findings:
• Insulated carafe is responsible for the most dramatic
energy savings
• Stainless steel would be an easy substitute for the glass
carafe
Recap
Redesign
Conclusions
Final Conclusions and Changes
1.Insulated Carafe
2.Reusable Stainless Steel Filter
3. 8-Cup Water Capacity
4.Location of the Heating Element
Recap
Redesign
Conclusions
Works Cited
http://www.buyspares.co.uk/tefal/coffee-makers/896115-vitesse-coffeemaker/catalogue.pl?shop=tefal&path=290047&model_ref=41271&illustration_ref=27443
http://www.statista.com/statistics/220433/life-expectancy-of-coffee-machines/
http://www.energystar.gov/ia/products/downloads/ENERGY_STAR_Scoping_Report_Coffee_Makers.pdf
Recap
Redesign
Conclusions