1. Announcement
Rapid and Early Energy Modeling for the Engineers for a Sustainable World
Shah Smith and Associates
Scott Sevigny
Wesley Stidham
March 8th, 6pm in ETC 2.132

2. Objectives Finish cooling cycles and cooling system components
Learn about refrigerants

3. Multistage Compression Cycles
Combine multiple cycles to improve efficiency
Prevents excessive compressor discharge temperature
Allows low evaporating temperatures (cryogenics)

4. Systems: residential
Outdoor Air
Indoor Air

5. System components Large building system
Water to
cooling tower
Water form
cooling tower
25oC
35oC
Plate heat
exchanger
6oC
11oC
Water to
building
Water from
building

6. Chiller

7. Compressors

8. Reciprocating compressor

9. Scroll compressor

10. Screw compressor

11. Rotary Compressor

12. Refrigerants

13. What are desirable properties of refrigerants?
Pressure and boiling point
Critical temperature
Latent heat of vaporization
Heat transfer properties
Viscosity
Stability

14. In Addition…. Toxicity Flammability Ozone-depletion
Greenhouse potential
Cost
Leak detection
Oil solubility
Water solubility

15. Refrigerants What does R-12 mean? ASHRAE classifications
From right to left ←
# fluorine atoms
# hydrogen atoms +1
# C atoms – 1 (omit if zero)
# C=C double bonds (omit if zero)
B at end means bromine instead of chlorine
a or b at end means different isomer