Presentation is loading. Please wait.

Presentation is loading. Please wait.

HVAC Excellence National HVACR Educators – Trainers Conference & Expo March 18-20th, 2013 Las Vegas, NV Donald Prather Technical Services Specialist Air.

Similar presentations


Presentation on theme: "HVAC Excellence National HVACR Educators – Trainers Conference & Expo March 18-20th, 2013 Las Vegas, NV Donald Prather Technical Services Specialist Air."— Presentation transcript:

1 HVAC Excellence National HVACR Educators – Trainers Conference & Expo March 18-20th, 2013 Las Vegas, NV Donald Prather Technical Services Specialist Air Conditioning Contractors of America Manual J8 ® Training Materials

2 The Air Conditioning Contractors of America (ACCA) The only nationwide association representing the technical, educational, and policy interests of U.S. businesses that design, install and maintain indoor environmental systems

3 ACCA History National Warm Air Heating and Air Conditioning Assn. (1914) Air Conditioning and Refrigeration Contractors of America (1946) National Environmental Systems Contractors Assn. (1968) Air Conditioning Contractors of America (1969)

4 Don’s History Maryland 1 st Class Stationary Engineer Licensed HVAC Contractor in Florida BS Mechanical Engineering Technology Thomas Edison State College ACCA Technical Service Manager

5 How Many Here Teach Manual J8 Load Calculations? 126 Pages 556 Pages 250 Pages

6 Manual J7 Hand Sheets vs Manual J8 Hand Sheets vs

7 Manual J7 Hand Sheets vs Manual J8 Hand Sheets vs

8 ACCA Instructor Power Point The intent of this series of MS Power Point® presentations is to provide instructors with varying levels of experience the building blocks to teach the residential HVAC design process over a wide variety of time frames.

9 ACCA Instructor Power Point The material was designed to be used by time-strapped instructors familiar with Manual J7 who need course material to transition to the new Manual J8ae.

10 ACCA Instructor Power Point This step-by-step training material can be opened, modified, adapted, or changed to meet your needs. It can be pared down to a condensed overview of the residential HVAC system design process, for a full week of training as is, or expanded into a full semester or by adding case studies or additional examples, this material could cover a full school year.

11 ACCA Instructor Power Point ACCA also thanks the following for their recommendations and comments which sharpened the presentations even further: –Jack Bartell; Virginia Air Distributors –Glenn Hourahan, PE; ACCA Staff –Warren Lupson; Lupson & Associates –Hank Rutkowski, PE; HTR Consulting –David Swett; Omaha Public Power –Richard Welguiucz,; The Trane Company –Wes Davis; ACCA Staff

12 First Chapters of J8ae Instructor Complaint: “In Manual 7 we start with interesting stuff: the real meat! By the time I wade through the first two chapters of Manual J8ae I have lost my class.”

13 First Chapters of J8ae I will now try to briefly cover the pertinent information from the first two chapters in a quick and interesting way using the actual 12 slide presentation and a one page hand out summarizing the exceptions.

14 First Chapters of J8ae This will be a little challenging because you are not students so please have some patience if it seems I am covering stuff that you all know how to do better than I do. Drum Roll Please!

15 Residential Load Calculation Introduction

16 Miscellaneous Items Cell/mobile phones and pagers –Please turn off or set on vibrate mode to minimize disruptions to class –Please take cell phone conversations outside the training room Smoking stations outside –Not permitted inside the training room Restroom locations

17 Class Objective To provide the attendee a basic understanding of heat gain and loss calculations principles in Manual J8ae, to enable him or her to correctly use manual worksheets or the software calculation procedure on the spreadsheet in back the of manual.

18 Introduction “Long term success in the residential comfort system business depends a great deal on how well system capabilities match customer expectations. To accomplish this, contractors must work with the client first to establish realistic expectations and second to install a system that performs to those expectations.”

19 Do the contractor and the client have the same vision? Heating and cooling Temperature on each floor Humidity control Filtration and air quality System efficiency & operating cost Health and safety (mold, mildew & back drafting issues) Building code compliance Client Interview Drawing Used with permission from HARDI

20 The system must be compatible with negotiated list of performance criteria. –System concept (# of zones, single or two stage, etc.). System capability Drawing Used with permission from HARDI

21 Provide specified comfort & humidity control at design conditions. Provide acceptable comfort & humidity control at part-load conditions. Provide reasonable comfort at outdoor design conditions. Reduce the possibility of indoor mold and mildew. Optimize installing cost. Reduce operating cost. Improve reliability. Benefits of an Accurate Load Calculation Drawing Used with permission from HARDI

22 Translate to smaller equipment. Translate to smaller duct airways and increased duct system efficiency. Minimize service loads imposed on utility grids. Translate to competitively priced proposals and quotes. Minimize “surprises” after the system is put into operation. Demonstrate “due diligence” in a court of law. Provide design values for sensible & latent equipment capacity. Benefits of an Accurate Load Calculation cont.

23 Cause discomfort during design-day weather. Produce marginal or unacceptable comfort at part- load conditions. Reduce the equipment’s ability to control indoor humidity. Cause short cycling effecting comfort, operating cost and reducing equipment life. Translates to large of equipment and ducts. Increased installed cost resulting is less competitive quotes. Increases loads on utility grids. Awkward position in a court of law. Consequences of Failing to Make a Detailed and Accurate Load Estimate

24 Your client is important. You are selling quality, performance and dependability. The comfort system is professionally designed and exceeds minimum standards and practices. Money spent on design work is a far better investment than money spent on excess capacity. You are providing value-added work. You can be trusted to do things the right way. You show you care. You make money. Business Issues

25 ACCA System Design Process

26 The End

27 Residential Load Calculation Section 2 – Making an Accurate Load Estimate

28 Miscellaneous Items Cell/mobile phones and pagers –Please turn off or set on vibrate mode to minimize disruptions to class –Please take cell phone conversations outside the training room Smoking Stations Outside –Not permitted inside the training room Restroom locations

29 Preparation of forms and worksheets – section 6. Survey - appendix 5. Protocols for estimating heating and cooling loads. –Manual J do’s (mandatory requirements). –Manual J don’ts (mandatory requirements). Making an Accurate Load Estimate

30 Order of procession for block load estimate –Worksheet A: design conditions –Worksheet B – C: window, glass doors & sky light loads –Worksheet D: opaque surface loads –Worksheet E: infiltration loads –Worksheet F: internal loads –Worksheet G: duct loads –Worksheet H: ventilation loads –Form J1ae: room load estimates Preparation of Forms and Worksheets

31 Manual J do’s (mandatory requirements) Use outdoor design conditions recommended by table 1 manual J. Use the default indoor design conditions recommended by manual J. Consider orientation of the structure on the site. Verify all construction details prior to calculating loads. Take full credit for all internal shading devices and external overhangs.

32 Manual J do’s (mandatory requirements) Use internal shading devices that are compatible with the type of room. Take credit for insect screens when installed or specified. Take full credit for rated performance of construction materials, insulation and construction features. Take full credit for tightness of of the envelope construction. Follow the manual J procedures for infiltration and ventilation.

33 Manual J do’s (mandatory requirements) Take full credit for duct system sealing and insulation. Match location as close as possible when selecting a duct load table. Match duct supply and return system geometry. Use the correct R-values for duct wall insulation. Add blower heat to the sensible gain if equipment performance data is not adjusted for blower heat.

34 Manual J Don’ts Do not use Manual J for commercial applications. Do not use MJ8ae to estimate loads not compatible with the overview for this manual. Do not design for record breaking weather conditions. Do not add a “safety factor” to table 1A. Do not design for abnormally low or high indoor temperature or humidity conditions. Do not assume there is no internal shading. Do not fail to take full credit for overhangs.

35 Do not assume that the load for the worst- case site orientation can be used for other orientations. Do not reduce known ceiling, wall or floor R-values “just to be safe”. Do not fail to give full credit for the builder’s effort to produce a tight envelope. If a local code specifies a fresh air requirement, do not assume the infiltration rate will satisfy this requirement. Manual J Don’ts

36 Do not assume that windows and doors will be open when making the infiltration estimate. Do not make worst case “everything is going full blast” assumptions about internal loads. Do not add extra occupancy loads for “entertaining groups of people.” Do not add internal loads for special events. Manual J Don’ts

37 Do not arbitrarily assume that ducts are unsealed. Do not fail to give full credit for efforts to provide tight, properly insulated ducts. Do not apply “safety factors” during any stage of the load calculation process. Do not apply a “safety factor” to the final answer or to the equipment selection procedure. Manual J Don’ts

38 Improper practices. (Do not use “rules-of- thumb”)! Know your software and read the MJ8 text! Using software for manual J calculations. Conclusion. Making an Accurate Load Estimate

39 THE END

40 Principles of Math: Appendix 4 J8ae This section should be covered sooner rather than later and will help students who need a quick math review as well as students that need to learn a little about building construction and materials..

41 Residential Load Calculation Appendix 4 – Physical Principles and Mathematics

42 Miscellaneous Items Cell/mobile phones and pagers –Please turn off or set on vibrate mode to minimize disruptions to class –Please take cell phone conversations outside the training room Smoking stations outside –Not permitted inside the training room Restroom locations

43 Course Objective Understand the physical principles and mathematics necessary to calculate the heat loss and gain for a residential building

44 Physical Principles & Mathematics Appendix 4 References – pg.163 Units of measurement and measurements protocols. –Measured dimensions. –Areas of building components. –Perimeters and volumes.

45 Formulas Area (rectangle)= length x height Area (triangle) = base x height x 0.5

46 Formulas Gross area = rectangular + triangular area Volume of a box = length x width x height Triangular prism volume = length x width x height x 0.5

47 Ceiling Area Calculation for Sloped Ceilings MJ8 Table A4-1 pg. 412 MJ8ae Table A4-1 pg. 164

48 Temperatures dry bulb & wet bulb. –Temperature scales (°F/°C). Based on affect of heat on water. Boiling and freezing points. F = C° x 9/ C = 5/9 x (F° - 32) Physical Principles & Mathematics Appendix 4 Drawings Courtesy of HARDI

49 Residential Load Calculation Appendix 4 – Physical Principles and Mathematics

50 How do We Measure Heat? British Thermal UnitBasic unit of measurement is British Thermal Unit BTU. Amount of heat to change 1 lb. of water 1°F. Drawing Courtesy of HARDI

51 Physical Principles & Mathematics Appendix 4 Sensible heat causes a change in temperature but no change in state. –Types of sensible transfer. Latent heat causes a change in state but no temperature change. –Types of latent heat transfer. Drawings Courtesy of HARDI

52 Physical Principles & Mathematics - Cont. Sensible and latent heat equations. –Sensible Btuh = 1.1 x ACF x CFMx ∆T –Latent Btuh = 0.68 X ACF X CFM X Grains Sensible Heat Ratio (SHR). –SHR = Sensible cooling load Btu/h Total cooling load Btu/h

53 Modes of Heat Transfer Conduction - The flow of heat through a material, or other material in contact with it. Drawing Courtesy of HARDI

54 Convection - The transfer of heat from a surface to a liquid or gas or vice versa depending on which is hotter. Modes of Heat Transfer Drawing Courtesy of HARDI

55 Radiation - The transfer of energy by electromagnetic waves. Modes of Heat Transfer Drawing Courtesy of HARDI

56 Physical Principles & Mathematics - Cont. Material properties - see table A1-3 –Thermal conductivity = 1/ R (resistance) per inch. –Thermal conductance = Conductivity x Thickness –Thermal resistance = 1/ U (conductance)

57 Physical Principles & Mathematics - Cont. R-values pg. 170 –Table A1-3 R-values for materials. –R per Inch = 1/ U value (conductivity) per in. –R t = R1 + R2 + R3 + R4 etc.

58 Air film coefficient Outside Air Film Inside Air Film Physical Principles & Mathematics - Cont.

59 R-Values for Common Construction Materials

60 Table A4-3 pg. 184

61

62 Table A4-3 pg. 185

63

64 R-Values for Common Insulations Pg. 171

65 R-Values Compression Adjustment pg. 171 R %

66 R-Values for Common Construction Materials

67 Physical Principles & Mathematics - Cont. Transmission coefficient pg. 172 U value = 1btuh per sq. Ft. Per hr. Drawing Courtesy of HARDI

68 Physical Principles & Mathematics - Cont. Whole panel u-values. U-value estimate issues. U-value calculations. U value = 1___ R t value U value = 1__ =.07 BTU 14.45

69 Temperature and temperature differences Physical Principles & Mathematics - Cont. 70°F - 0°F = 70°F TD Drawing Courtesy of HARDI

70 Daily range. Physical Principles & Mathematics - Cont.

71 Heat transfer multiplier (HTM) HTM = U value X temp. Diff. Heat loss HTM for opaque panels. –Heat loss HTM for slab floors. –Effective opaque panel gain. –Heat gain HTM for opaque panels.

72 Physical Principles & Mathematics - Cont. Heat loss HTM for fenestration, opaque panels. –Effective heat gain for windows and glass doors. –Effective heat gain for skylights. Default heat gain HTM for generic fenestration. Overhang adjustment for window and glass door HTM.

73 Physical Principles & Mathematics - Cont. Duct loads Duct sealing Supply air moving through ducts can experience a significant temperature drop or rise resulting in large loads for heating/cooling units.. Cooling Supply Ducts passing through an unconditioned space must be insulated and sealed with a vapor barrier. Drawings Courtesy of HARDI

74 Physical Principles & Mathematics - Cont. Blower heat. 1,707 Btuh Moisture migration. Cold side Warm side Moisture Migration Drawing Courtesy of HARDI

75 THE END

76 JUMP TO SECTION 6 PART 2 Residential Load Calculation Room Load Estimate

77 Residential Load Calculation Section 6 (Part 2) Room Load Estimate

78 Class Objective Upon completion, the attendee should be able to calculate a cooling and/or heating load for a residential single-family structure using Manual J8ae, worksheets and a pocket calculator.

79 ACCA House w/add Valparaiso, IN M

80 Table 6A Internal Loads

81 Worksheet: Form J1ae ACCA House w/add Valparaiso, IN M We will added up sub totals later. 800 (12 small,6 med & 4 large plants)) In RM Loads

82

83


Download ppt "HVAC Excellence National HVACR Educators – Trainers Conference & Expo March 18-20th, 2013 Las Vegas, NV Donald Prather Technical Services Specialist Air."

Similar presentations


Ads by Google