1. Cooling Systems HVAC 11a CNST 305 Environmental Systems 1 Dr. Berryman 12aCooling Systems; Refrigerants; Condenser/Evaporator Compressive; Absorption; Evaporative; Chillers; Heat Sinks Chapter 4 (Toa)

2. Air Conditioning Definition Process of treating air in an internal environment to establish and maintain required standard of temperature, humidity, cleanliness, and motion.

3. Heat Transport Systems Air Water Steam A/C Systems can use one…or a combination of transports

4. Components - A/C System Minimum Components

5. Cooling Equipment Common refrigeration systems Used for different applications and climates

6. Compression Cycle Fundamentals Refrigerant characteristic Boiling Point Condensing Point Saturation Point All three have the same numerical value

7. Refrigerants Refrigerant: R-123, R-22, R12 Water: R-718 Carbon Dioxide: R-744 Ammonia: R-717

8. Boiling Point of Water temperature pressure 212°F[100°C] 14.7 psia [0.10MPa]

9. Refrigerant R-22 -41.4°F[-40.8°C] R-22 boils at

10. Boiling Point of R-22 41.2°F[5.1°C] 85 psia [0.59 MPa] 121.5°F[49.7°C] 280 psia [1.93 MPa] temperature pressure

11. Effects of Pressure Increase in pressure on a refrigerant Results Increased boiling, condensing, and saturation points Decrease in pressure on a refrigerant Increased boiling, condensing, and saturation points

12. Refrigeration Cycle liquid refrigerant (R-22) -41.4°F[-40.8°C] airflow collects refrigerant vapor

13. Refrigeration Cycle ? Closing the Cycle

14. Refrigeration Cycle compressor condenser expansiondevice evaporator

15. Evaporator refrigerant vapor mixture of liquid and vapor refrigerant B A air

16. Compressor low-pressure refrigerant vapor from evaporator C B high-pressure refrigerant vapor to condenser

17. Condenser C D refrigerant vapor liquidrefrigerant outdoor air

18. Expansion Device A D liquidrefrigerant mixture of liquid and vapor refrigerant

19. Basic Refrigeration System compressor condenser evaporator Direct expansion device (DX) dischargeline suctionline liquidline A B C D

20. DX Packaged Unit

21. SEER vs HSPF SEER Seasonal Energy Efficiency Ratio Index of MPG for a/c Number of BTU’s removed by 1 watt of electricity Rating range from 8 – 14 SEER Water cooled condensers can achieve higher (system w/ water tower) HSPF for heat pumps Heating Seasonal Performance Factor BTU per watt

22. Split System Cooling

23. Heat Pump Reversible Refrigeration System

24. COP Coefficient of Performance (1-5) Commercial Heating efficiency index COP of 1 = 3,400 BTU/Kw Strip heaters, toasters, water heaters, etc. COP 2 3,400 BH electrical - 3,400 OA environment TOTAL 6,800 BH COP 3 3,400 BH electrical – 6,800 OA environment TOTAL 10,200 BH HSPF -Heating Seasonal Performance Factor BTU per watt – Heating index for Residential COP 2 = HSPF 6.8

25. Air Source Heat Pump COP Heat Pump COP changes w/ source temperature

26. Large A/C Equipment Air HandlerChillerCooling Tower

27. Air Handler Fan/Coil Unit

28. Chiller - Compression Cut Away – Rotary Helical Chiller Reciprocating Cylinder displacement Scroll Scroll displacement Rotary Helical Screw - type Centrifugal impellers

29. Water Towers Central Plant 500 – 30,000 GPM

30. Chillers - Absorption condenser generator evaporator absorber

31. Refrigerant Distilled water Stable Nontoxic Low cost Readily available Environmentally friendly High latent heat of vaporization

32. Boiling Point of Water 1.5 psia [10.34 kPa] 0.15 psia [1.034 kPa] temperature pressure 45°F[7.2°C] 115°F[46.1°C]

33. Absorbent Lithium Bromide (LiBr) High affinity for water (refrigerant) In solution, higher boiling point than water Nontoxic

34. Absorption Cycle condenser evaporator absorber generator chilled water cooling water steam or hot water heatexchanger Air Handler Cooling Tower Boiler High Pressure Low Pressure Cooling Tower

35. Absorber coolingwater refrigerantvapor concentratedsolution intermediatesolution absorber spray pump dilutesolution absorber 100°F 0,15 psi From Cooling Tower To generator

36. Generator steam or hot water dilutesolution refrigerantvapor concentratedsolution generator

37. Condenser coolingwater refrigerantvapor liquid refrigerant condenser 115°F 1.5 psi

38. Evaporator chilledwater evaporator spray pump refrigerantvapor liquid refrigerant absorber evaporator Air Handler 45°F 0,15 psi

39. Expansion Device liquid refrigerant expansiondevice evaporator

40. Heat Exchanger generator pump dilutesolution heatexchanger concentratedsolution precools the concentrated solution