Max Tech and Beyond challenged university teams to design and build energy efficient appliances that go beyond current technology on the market. As part of the competition, teams had to present their results during a webinar on May 23, 2012. The presentation from the winning team -- the University of Maryland -- explains its design for a wall air conditioner with separate systems for cooling and removing moisture from indoor air.

1. Team SSLCAC
Final Progress Report
Lead Faculty: Prof. Yunho Hwang
Student Presenter: Michael Siemann
May 23, 2012
MaxTech and Beyond Appliance Design Competition, AY2011/2012

2. Project Goal
• Target Appliance: Wall Air Conditioner (1Ton)
• Technology Applied:
• Separate Sensible and Latent Cooling
• Radiative Cooling Wall
• Innovative Polymer Desiccant
• Energy Savings Goal: 30%
MaxTech and Beyond Appliance Design Competition, AY2011/2012

3. Baseline Wall Air Conditioner
Cool Dry Air Needs to generate temperatures
much colder than desired air
Warm Moist
Air
LG LT103HNR (10,000 BTU)
Modified from: <HowStuffWorks.com>
MaxTech and Beyond Appliance Design Competition, AY2011/2012

4. SSLCAC Design Overview
Radiative Cooling Wall
Desiccant Wheel
Separate Sensible
and Latent Cooling
Angled View of Contained Unit
MaxTech and Beyond Appliance Design Competition, AY2011/2012

5. SSLCAC Design Overview
Regenerative
Main Condenser Condenser Evaporator Fan
Desiccant
Fan
Condenser Damper
Desiccant Wheel
Fan
Compressor
Evaporator
RHX
Top View of Contained Unit
MaxTech and Beyond Appliance Design Competition, AY2011/2012

6. SSLCAC Design Overview
Outside Inside
Regenerative
Main Condenser Condenser Evaporator Fan
Desiccant
Fan
Condenser Damper
Desiccant Wheel
Fan
Compressor
Evaporator
RHX
Top View of Contained Unit
MaxTech and Beyond Appliance Design Competition, AY2011/2012

7. SSLCAC Design Overview
VCC Only Outside Inside Cooling Only
Regenerative
Main Condenser Condenser Evaporator Fan
Desiccant
Fan
Condenser Damper
Desiccant Wheel
Fan
Compressor
Evaporator
RHX
Top View of Contained Unit
MaxTech and Beyond Appliance Design Competition, AY2011/2012

8. SSLCAC Design Overview
Desiccant Only Outside Inside Dehumidification
Regenerative Small heating
Main Condenser Condenser Evaporator Fan
Desiccant
Fan
Condenser Damper
Desiccant Wheel
Fan
Compressor
Evaporator
RHX
Top View of Contained Unit
MaxTech and Beyond Appliance Design Competition, AY2011/2012

9. SSLCAC Design Overview
Full System Outside Inside Dehumidification
Regenerative Cooling
Main Condenser Condenser Evaporator Fan
Desiccant
Fan
Condenser Damper
Desiccant Wheel
Fan
Compressor
Evaporator
RHX
Top View of Contained Unit
MaxTech and Beyond Appliance Design Competition, AY2011/2012

10. SSLCAC Design Overview
Thermal Images RHX
• Sensible Cooling System
• VCC with higher Tevaporator
= smaller compressor
• Radiative HX = lower power
fan and better distribution
MaxTech and Beyond Appliance Design Competition, AY2011/2012

11. SSLCAC Design Overview
• Sensible Cooling System Desiccant Wheel
• VCC with higher Tevaporator
= smaller compressor
• Radiative HX = lower power
fan and better distribution
• Latent Cooling System
• Desiccant wheel = low
power dehumidification 50℃ regeneration
• Free heat to regenerate
desiccant from condenser
MaxTech and Beyond Appliance Design Competition, AY2011/2012

12. SSLCAC Design Overview
• Sensible Cooling System
• VCC with higher Tevaporator
= smaller compressor
- 30%
• Radiative HX = lower power
fan and better distribution - 5%
• Latent Cooling System
Desiccant wheel = low
•
power dehumidification
+ 1%
Free heat to regenerate
•
desiccant from condenser
+ 4%
• Translates into energy
savings 30%
MaxTech and Beyond Appliance Design Competition, AY2011/2012

13. SSLCAC Experimental Evaluation
Applied ASHRAE Standard
T
T
P1
T T
T
TXV
Desiccant Wheel VFR
T
T RH2 P3
P2
T
T
T RH3
Air Blender
From tap
Qevap Power
COPe =
Wcompressor + ∑W fan,i T RH1
i
MaxTech and Beyond Appliance Design Competition, AY2011/2012

14. Test Results
SSLC
Parameter
Baseline
VCC Only VCC-RHX VCC/RHX/DW
Pevap [kPa]
951
1097 1221 1164
Pcond [kPa]
2481
2456 2405 2403
Tevap [°C]
3.81
9.7 13.5 11.7
Tcond [°C]
41.20
40.8 39.9 39.9
Superheat [°C]
1.58
2.22 0.71 0.78
Subcooling [°C]
7.58
3.27 0.54 0.47
Mass Flow Rate [g/s]
16.4
19.3 22.0 20.8
Wtotal [kW]
0.94
0.94 0.85 0.85
Qevap [kW]
2.75
3.20 3.54 3.34
COPe
2.91
3.34 4.15 3.92
MaxTech and Beyond Appliance Design Competition, AY2011/2012

15. Test Results
SSLC
Parameter
Baseline
VCC Only VCC-RHX VCC/RHX/DW
Pevap [kPa]
951
1097 1221 1164
Pcond [kPa]
2481
2456 2405 2403
Tevap [°C]
3.81
9.7 13.5 11.7
Tcond [°C]
41.20
40.8 39.9 39.9
Superheat [°C]
1.58
2.22 0.71 0.78
Subcooling [°C]
7.58
3.27 0.54 0.47
Mass Flow Rate [g/s]
16.4
19.3 22.0 20.8
Wtotal [kW]
0.94
0.94 0.85 0.85
Qevap [kW]
2.75
3.20 3.54 3.34
COPe
2.91
3.34 4.15 3.92
26% Higher COP
MaxTech and Beyond Appliance Design Competition, AY2011/2012

16. Future Work (before competition end)
• Prototype Tuning
• Components
• Refrigerant and air side
• SEER Testing
• Multiple test conditions
• Transient Testing and Simulations
• Multiple climate zones
• True value of SSLC
• Product Cost Estimation
• Videos:
<www.youtube.com/user/TeamUMDSSLCAC?feature=mhee>
MaxTech and Beyond Appliance Design Competition, AY2011/2012

17. Conclusion
• Target Appliance: Wall Air Conditioner
• Innovation:
• Separate Sensible and Latent Cooling
• Radiative Cooling Wall
• Low Regeneration Temperature Polymer
Desiccant
• Energy Savings Goal: 30%
• Tested Prototype Energy Savings: 26%
• Projected Energy Savings: 30%
Project was a success!
MaxTech and Beyond Appliance Design Competition, AY2011/2012

18. Acknowledgements
• Team members: Angle, Jon (G); Corfman, Kyle (UG); DeGennaro,
David (UG); Foo, Andrew (UG); Ganye, Randy (UG); Genes, James (UG);
Hesser, Nicholas (UG); Kang, Inhye (UG); Knapp, Bryan (G); Li, Gang (G);
Li, Seaver (UG); Li, Song (G); Long, Hung (G); Mandel, Bracha (G);
Olszewski, Aaron(UG); Popli, Sahil (G; Qian, Suxin (G); Sy, Hannele (UG);
Vaaland, Oeyvind (G); Vu, Lam (UG); Zhou, Yvonne (UG)
• Lead PI: Dr. Yunho Hwang
• Post-Doc: Dr. Jiazhen Ling
• Student Lead: Michael Siemann
• Funding: DOE, EERE, BT
• Special Thanks: LBNL, Stacy, Kimberly
MaxTech and Beyond Appliance Design Competition, AY2011/2012