Some Basic HVAC

Some Basic HVAC

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Some Basic HVAC

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1. Some Basic HVAC

2. HVAC - Cooling First Law of Thermodynamics Enthalpy H = U + PV Second Law:Entropy dS = dQ/T

3. HVAC - Cooling Second Law:Entropy

4. HVAC - Cooling ideal COP – dimensionless! – EER – dimensions of Btu/h/W! kpH’ evQ

5. HVAC - Cooling kpH’ evQ COP = evQ / kpH’ = (h1-h4) / (h2-h1)

6. HVAC - Cooling COP = evQ / kpH’ = (h1-h4) / (h2-h1) Nipuna

7. HVAC - Cooling Stay away from Window Air Conditioner

8. HVAC - Cooling Split System

9. HVAC - Cooling Cooling Tower Chilled-water System

10. HVAC - Cooling Reciprocating Compressor Scroll Compressor Chilled-water System

11. HVAC - Cooling Chilled-water System Chilled-water System:Centrifugal Compressor

12. HVAC - Cooling Rooftop Units

13. HVAC - Cooling Rooftop Units

14. HVAC - Cooling Rooftop Units

15. HVAC - Cooling Saturation humidity line: Relative humidity line Wet bulb temperature lines Specific volume lines Enthalpy lines Psychrometric Chart

16. HVAC - Cooling

17. HVAC - Cooling The energy efficiency rating (EER) of an air conditioner is its BTU/h rating over its Wattage. Example: window air conditioner Rating: 10,000-BTU/h Power Consumption: 1,200 watts EER = 10,000 BTU/h/1,200 watts = 8.3 Btu/Wh Normally a higher EER is accompanied by a higher price.

18. HVAC - Cooling • Choice between two 10,000-BTU/h units • 1. EER of 8.3, consumes 1,200 watts • EER of 10, consumes 1000 watts. • Price difference is \$100. • Usage: 4 months a year, 6 hours a day. • Electricity Cost: \$0.10/kWh. • =========================================== • 4 mo. x 30 days/mo. x 6 hr/day = 720 hours • (720 h x .2 kW) x \$0.10/kWh = \$14.40 Savings • Since the EER 10 unit costs \$100 more, • it will take about seven years for this more expensive unit • to break even

19. HVAC - Cooling

20. HVAC - Cooling

21. HVAC -Heating High Efficiency Upflow Furnace Efficiency: .8 - .95

22. HVAC -Heating FIRETUBE BOILER

23. HVAC -Heating Disadvantages of Firetube Boilers include: Not suitable for high pressure applications 250 psig and above Limitation for high capacity steam generation Disadvantages of the Watertube design include: High initial capital cost Cleaning is more difficult due to the design No commonality between tubes Physical size may be an issue FIRETUBE BOILERS WATERTUBE BOILERS

24. HVAC -Heating Scotch Boiler

25. HVAC -Heating

26. HVAC -Heating

27. HVAC -Heating Thermostatic Steam Traps Mechanical Steam Traps

28. HVAC -Heating Thermodynamic Steam Traps Orifice Steam Traps

29. HVAC -Heating Determination of Efficiency

30. HVAC -Heating

31. HVAC -Heating

32. HVAC Motors Radial Flow belt driven Fan

33. HVAC Fans Radial Flow belt driven Fan

34. HVAC Motors velocity p static dp Total p B = C + A

35. HVAC Motors

36. HVAC Motors Variable Frequency Drive is closest to Centrifugal Fan Law

37. HVAC Motors Variable Speed Drive

38. HVAC –Ventilation Distribution System and Controls

39. HVAC –Ventilation Circulation Systems

40. HVAC –Ventilation Circulation Systems Two Duct System

41. HVAC –Ventilation Circulation Systems Four Pipe Systems

42. HVAC - Envelope Building Envelope

43. HVAC - Envelope Building EnvelopeNipuna en:p:ÙN:

44. HVAC - Envelope Building EnvelopeNipuna en:p:ÙN:

45. HVAC - Envelope Building Envelope – HDD/CDD Data

46. HVAC - Envelope Building Envelope Values from G. Pita “Air Conditioning and Principles”, 2002

47. HVAC - Envelope Building Envelope NY Data

48. HVAC - Envelope Building Envelope NY Data

49. HVAC - Envelope Windows

50. HVAC - Envelope Windows