1. Stick computers in oil Spring 2009 Engr 45 By, Sergy Pretetsky & Jeff Hitchcock

2. Why computers need cooling Greater conductivity at low temperatures Avoid critical failure Overheating= over stressing components

3. Common Computer cooling Air cooled heatsinks Water cooling Peltier cooling Phase change cooling Liquid nitrogen & Dry ice and acetone

4. Thermal properties (water vs. air) Volumetric Heat capacity (Jcm -3 K -1 ) –Water - 4.186 –Air - 0.001297 Thermal conductivity (W/(m·K)) –Water - 0.6 –Air - 0.025 Heat Transfer Coefficients –Water – 500-10,000 W/(m 2 K) –Air – 10-100 W/(m 2 K)

5. Thermal properties (water vs. oil) Volumetric Heat capacity (Jcm -3 K -1 ) –Water - 4.186 –Oil - ~2 (FAR more than air) Thermal conductivity (W/(m·K)) –Water - 0.6 –Oil -.15 (60 times more than air) Heat Transfer Coefficients –Water – 500-10,000 W/(m 2 K) –Oil – ?

6. The complete set up

7. The Tub

8. The Oil The Computer submerged

9. The Overclocking test

10. Thermal paste test

11. Results Long term test Processing remained the same Problems –Plastics –Heat retention in oil

12. Results Overclocking Test With oil –no additional performance Old computer –possibly maxed out components –If we had new computer, could have pushed it further

13. Results Thermal Paste test Out of 3 popular thermal pastes –1 was dissolved away –2 were unaffected @ RT –Possibly more degrading at running temps

14. Conclusion With an old computer –Didn’t help boost performance Didn’t cause failure What to do next time Use a radiator to cool the oil Keep power supply separate

15. Sources http://en.wikipedia.org/wiki/Specific_heat_capacity http://en.wikipedia.org/wiki/Heat_transfer_coefficient http://www.medwelljournals.com/fulltext/jeas/2006/495- 499.pdfhttp://www.medwelljournals.com/fulltext/jeas/2006/495- 499.pdf http://www.mobil.com/USA- English/Lubes/PDS/glxxenpvlmomobil1_truck_suv_5w- 30.pdfhttp://www.mobil.com/USA- English/Lubes/PDS/glxxenpvlmomobil1_truck_suv_5w- 30.pdf http://www.engineeringtoolbox.com/thermal-conductivity- d_429.htmlhttp://www.engineeringtoolbox.com/thermal-conductivity- d_429.html