1. Objective Learn about Cooling and Cooling systems Define heat pump Learn about energy storage systems

2. Refrigeration Cycle

3. 92 °F 56 °F 69 psig DB = 77 °F WB = 64 °F orifice capillary tube TXV 110 °F ~200 psig DB = 60 °F WB = 53 °F High pressure, high boiling/condensing point Low pressure, low boiling point DX Cooling Machine

4. Air Cooled Chiller Outside air 95°F Inside 75°F Water 42°F Building Water 52°F Chiller

5. Water Cooled Chiller Outside air 95°F Inside 75°F Water 42°F Building Water 52°FWater 120°F Water 100°F Cooling tower Chiller

6. Cooling Evaporative cooling Compressor Cooling Sorption cooling DX machine Chiller Air Cooled Condenser Water Cooled Condenser Convert Cooling machine (DX machine) to heat pumps Evaporative Chiller

7. Air cooled condenser Only for small capacity Cool the water or directly the refrigerant for compressor chillers

8. Cooling tower Provide cooling water for condenser or absorption Type Location Water need some treatment - Legionella !

9. What is Heat Pump ? Cooling Heating Outside 95°F Outside 55°F Inside 75°F

10. COP for heat pump

11. www.srpnet.com/energy/pumpworks.aspx 1) Compressor 2) Condenser 3) Evaporator 4) Air handler 5) Reversing valve and expansion valve

12. Evaporative Cooling Wet media/water spray – direct Raise absolute humidity, lowers temperature of conditioned air Cooling tower – indirect Cools through a heat exchanger Lowers temperature, does not affect absolute humidity Can directly cool air in cold weather

13. Can you use the steam for cooling? A Yes B No

14. Absorption Cycle Water is typical refrigerant Strong vacuum - ~0.116 psi or 0.0008 MPa Boiling point of water? Differences from vapor compression No compressor Chemical (e.g. LiBr - hygroscopic) –Absorbs water vapor turns it into a liquid –Regenerated by removing water Requires heat

15. Absorption Cycle Strong vacuum Refrigerant: water Absorber: lithium bromide Replace compressor

17. Evaporative Cooling Wet media/water spray – direct Raise absolute humidity, lowers temperature of conditioned air Cooling tower – indirect Cools through a heat exchanger Lowers temperature, does not affect absolute humidity Can directly cool air in cold weather

18. Evaporative Cooling

19. Cooling Evaporative cooling Compressor Cooling Sorption cooling DX machine Chiller Air Cooled Condenser Water Cooled Condenser Convert Cooling machine (DX machine) to heat pumps Evaporative Chiller

20. Energy Storage Systems

21. Daily distribution of cooling load

22. Thermal Storage Make ice/chilled water at times of low demand or low energy prices Store water in insulated container Can be used to reduce overall demand Water can be used as secondary water source for fire protection Ice/snow

23. Thermal Storage

24. Reading Assignment Tao and Janis - whole Chapter 4