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1 Ed Janowiak Eastern Heating & Cooling Council eh-cc.org.

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Presentation on theme: "1 Ed Janowiak Eastern Heating & Cooling Council eh-cc.org."— Presentation transcript:

1 1 Ed Janowiak Eastern Heating & Cooling Council eh-cc.org

2 2  Lincoln Tech 84  Spent 15 years in a van  HVAC & Weatherization  Started teaching RSES classes  EHCC  NATE  BPI Ed Janowiak

3 3 If nothing else……. If nothing else……. I promise everyone what I’m going to tell is 100% true, not opinion it’s fact…. I promise everyone what I’m going to tell is 100% true, not opinion it’s fact….

4 4 Why use Manual J ?  Provide Specified comfort and humidity control at design conditions  Provide Specified comfort and humidity control at part-load conditions  Provide reasonable comfort at outdoor design conditions  Reduce possibility of Mold and Mildew

5 5  Optimize installed cost  Reduced operating costs  Improved reliability (minimize short cycling)  Translate to smaller duct airways and increased duct system efficiency  Minimize service loads imposed on utility grids Benefits of a Detailed and Accurate Load Calculation

6 6continued….  Translates to competitively priced proposals and quotes  Minimize “surprises” after the system is put into operation (problems with comfort, mold, mildew, health, safety, and operating cost or a letter from a lawyer)  Demonstrate “due diligence” in a court of law  Provide design values for sensible and latent equipment capacity

7 7 Benefits of an over-sized system

8 8 How do you size equipment?

9 9 The finger method ?

10 10 The finger method

11 11 The finger method

12 12 2 & 1/4 fingers or a 2.5 ton house

13 13 Square Foot per ton?

14 14 Here’s 1 reason square footage per ton is BS

15 15 A little house 400 sqft 20x20 10x40

16 = 80’

17 = 100’

18 18 So right there………….. 80 running feet vs. 100 running feet but both spaces are 400 square feet

19 19 That same little house 400 sqft 20x20 10x40

20 20 Windows 400 sqft Lots of glass

21 sq ft Windows Very little glass

22 22 How do those 2 spaces compare? Yah, you’re right …. they don't

23 23 What does Manual J really do?

24 24 Manual J Load Calculations  Heat loss and Cooling design conditions  Accuracy important!  Q = U x A x  T  Internal load  Ventilation load  Infiltration  These, and lots more too

25 25 ` MJ8 AE Speed Sheet current version

26 26 Written form

27 27

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29 29 Remember  We don’t design to historic highs  We don’t design to historic lows  Do you want a system that is at it’s best <10% of the time?  Or do we want a system that is at it’s best > 90% of the time?

30 30

31 31 Page 94 Table 1A

32 32

33 33 Page 94

34 34

35 35 South West 7x6=42 12x5= 60 House 50 X 35 R-19 Ceiling R-11 Walls R-11 Floors (over crawlspace) Double pane operable window – metal – W/ break Dark Roof Ducts in crawl R-6Front door (FD) Metal fiberglass W/ storm FD 3x7=213x5x3=45 3x4x3=36 3x4=12 3x4x2=24 3x4=12 Supply Return 3x3.33=10 BW 3’over hang front and back (N&S) all windows 1 foot from sofit, Bay Window (BW) has no overhang 8’ walls This is the example house we are doing FP

36 36 OK, Where do we start?  Doors  Walls  Glass  Ceilings  Floors  Lets just hit the tabs in order.

37 37 The Doors No this kind

38 38

39 39 South West 7x6=42 12x5= 60 House 50 X 35 R-19 Ceiling R-11 Walls R-11 Floors (over crawlspace) Double pane operable window – metal – W/ break Dark Roof Ducts in crawl R-6Front door (FD) Metal fiberglass W/ storm FD 3x7=213x5x3=45 3x4x3=36 3x4=12 3x4x2=24 3x4=12 Supply Return 3x3.33=10 BW 3’over hang front and back (N&S) all windows 1 foot from sofit, Bay Window (BW) has no overhang 8’ walls This is the example house we are doing FP

40 40 page 111

41 41

42 42 Windows are next

43 43 South West 7x6=42 12x5= 60 House 50 X 35 R-19 Ceiling R-11 Walls R-11 Floors (over crawlspace) Double pane operable window – metal – W/ break Dark Roof Ducts in crawl R-6Front door (FD) Metal fiberglass W/ storm FD 3x7=213x5x3=45 3x4x3=36 3x4=12 3x4x2=24 3x4=12 Supply Return 3x3.33=10 BW 3’over hang front and back (N&S) all windows 1 foot from sofit, Bay Window (BW) has no overhang 8’ walls FP

44 44 page 103 double

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48 48 Walls

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51 51 South West 7x6=42 12x5= 60 House 50 X 35 R-19 Ceiling R-11 Walls R-11 Floors (over crawlspace) Double pane operable window – metal – W/ break Dark Roof Ducts in crawl R-6Front door (FD) Metal fiberglass W/ storm FD 3x7=213x5x3=45 3x4x3=36 3x4=12 3x4x2=24 3x4=12 Supply Return 3x3.33=10 BW 3’over hang front and back (N&S) all windows 1 foot from sofit, Bay Window (BW) has no overhang N 34 SQ’ N 42 SQ’ E/W 36 SQ’ S 60 SQ’ S 81 SQ’ 253 SQ’ Of glass (don’t forget the front door) 8’ walls FP

52 52 Page 112

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57 57 page 18

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62 62 Manual S

63 63

64 64 Sizing Limitations  Cooling-only equipment should be sized so that the total cooling capacity does not exceed the total cooling load by more than 15%.  If heat pump equipment (air-source or water- source) is installed in a warm or moderate climate, the total cooling capacity should not exceed the total cooling load by more than 15%.  If heat pump equipment is installed in a cold climate (where heating cost are a primary concern), the total cooling capacity may exceed the total cooling load by as much as 25%.

65 65 “My unit runs constantly when it’s hot or cold out, it never shuts off”  Great!  It’s supposed too, I guess I did it right… yippee!!!!!!  It’s our job (or our students) to educate the consumer

66 66 Is Manual J always the way to go?  No  You have to have reasonably tight ducts  Adequate air flow  Right charge

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73 73 Seal-tight fittings

74 74 A little mastic

75 75 Correctly charged

76 76 Manual J Manual N Use these

77 77 Guess at sizing and you’ll end up too big or too small

78 78 Too big……

79 79

80 80 Too small

81 81 Just right

82 82 Questions?

83 83 MJ8 unabridged software venders  In no specific order  Elite  Adteck  Nitek  Wrightsoft  Free demos for each at their sites

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95 95 Heat only applications?

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99 99 So why are heating systems so oversized?  Greater heat loss?  No insulation  Crappy windows?  Open windows?  Huh?

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101  If you want to learn more about heat loads.  If you want to learn more about duct sizing  If you just want to learn more on almost anything in the HVAC/R.  Contact us ( Training for the Trades )  Web   Phone 24/


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