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 Psychrometric Chart 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 (720 h x .2 kW) x $0.10/kWh = $14.40 Savings
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:

22. HVAC -Heating
FIRETUBE BOILER

23. HVAC -Heating FIRETUBE BOILERS WATERTUBE BOILERS
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 Envelope Nipuna en:p:ÙN:

44. HVAC - Envelope
Building Envelope Nipuna 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

51. Modeling
eQuest and Power DOE