The document details a project by a team from UC San Diego aimed at designing a passive energy-efficient refrigeration system. The proposed solution includes a prototype with a clear plastic barrier and bottom-hinged drawers to minimize cold air loss when the refrigerator door is opened, resulting in a projected 12.3% energy saving. Preliminary testing indicates substantial reductions in energy usage compared to standard refrigerators, with potential market pathways and an estimated payback period for consumers.

1. Max Tech and Beyond
Appliance Design Competition
(Academic Year 2013/2014)
UCSD (P.E.E.R.S)
Passive
Energy
Efficient
Refrigeration
System
Thursday May 29th, 2014

2. Project Members:
• Joshua Cohen
• Josh Stiling
• Dane Sequeira (Student Lead)
• Jan Kleissl (Principal Investigator)
• Cameron Ravanbach
• Luke Calkins
• Lukas Syka
The Team

3. Project Goal
Appliance under modification: Refrigerator
Problem: Release of cold air when door opens
• Buoyancy driven convection
• Refrigerator consumes energy to drive
temperature back down
Proposed Solution: Restrict outward flow of cold
air during opening events

4. Prototype Development
Features
 Clear plastic barrier – Contents visible, effectively closed
 Bottom hinging drawers – smaller opening surface area restricts convective flow
10% Proposed Energy Saving Based On:
Reduced time subject to airflow
Reduced area subject to airflow
Discouraged buoyancy driven flow

5. About the Prototype
 Laser cut from a sheet of
clear ¼” acrylic
 Handles for opening
 Magnetic closure
mechanism
 Stopper mechanism
 Rubber seal along outer
edges

6. 20 sec 1 min 2 min
Without Prototype:
With Prototype:
20 sec 1 min 2 min
Preliminary Testing

7. Testing Equipment
 Five thermocouple temperature
sensors
 External humidity sensor
 Water containers to simulate
thermal mass
 Power consumption meter

8. Testing Method
 Fridge was run under
normal use conditions
with sensors in place
 Tests were performed
both with and without
the prototype in place
 The data was normalized
 Power consumption was
compared

9. 0
50
100
150
200
250
300
350
400
450
500
0 1 2 3 4 5 6 7
Watt-Hours
Hours
Energy Usage vs Time
No Panel
Results

10. y = 69.68x
0
50
100
150
200
250
300
350
400
450
500
0 1 2 3 4 5 6 7
Watt-Hours
Hours
Energy Usage vs Time
No Panel
Linear (No Panel)
Results

11. y = 69.68x
0
50
100
150
200
250
300
350
400
450
500
0 1 2 3 4 5 6 7
Watt-Hours
Hours
Energy Usage vs Time
No Panel
Panel
Linear (No Panel)
Results

12. y = 69.68x
y = 61.56x
0
50
100
150
200
250
300
350
400
450
500
0 1 2 3 4 5 6 7
Watt-Hours
Hours
Energy Usage vs Time
No Panel
Panel
Linear (No Panel)
Linear (Panel)
Results

13. Savings
42
43
44
45
46
47
48
49
50
51
52
53
Without Panel With Panel
kWh/Month
51.8
45.8
12.3% Energy Saving
over Energy Star Rated
Product

14.  Approximately $25 per unit
 Paths to market
 Partner with fridge manufacturers
 Direct consumer sales
Payback Period
4.5 years (Energy Star Rated Refrigerator)
11 months (Average Household Refrigerator)
Market Potential
Material Cost
~6 kg Acrylic $15
Hardware $5
Assembly $5
Total Cost $25

15. Acknowledgments
 Team Members: Dane Sequeira, Lukas Syka, Josh Stiling, Cameron Ravanbach,
Luke Calkins, Joshua Cohen
 University: University of California, San Diego
 Principal investigator: Jan Kleissl (jkleissl@ucsd.edu)
 Student Lead: Dane Sequeira (dsequeir@ucsd.edu)
 Funding: Department of Energy, EERE, Building Technologies Office,
Lawrence Berkeley National Laboratory
 References: Alan Meier (Refrigerator Energy Use in the Laboratory and in the
Field), R. Saidur (Role of Ambient Temperature, Door Opening, Thermostat
Setting Position and their Combined Effect on Refrigerator-Freezer Energy
Consumption), C. Inan (Heat and Mass Transfer Through a Domestic
Refrigerator and Evaluation of Evaporator Performance under Frosted
Conditions)