Chapter

GUIDELINES FOR IMPROVED DUCT DESIGN AND HVAC SYSTEMS IN THE HOME

GUIDELINES FOR IMPROVED DUCT DESIGN AND HVAC SYSTEMS IN THE HOME

CONTENTS

PREFACE

Chapter 1 ADVANCED STRATEGY GUIDELINE: AIR DISTRIBUTION BASICS AND DUCT DESIGN

DEFINITIONS

EXECUTIVE SUMMARY

1. OVERVIEW

2. PERFORMANCE CRITERIA

2.1. Temperature Mixing and Uniformity

2.1.1. Volume and Pressure of Air

2.1.2. Ductwork Materials and Configuration

2.2. Supply Outlets

2.2.1. Impact on Uniformity

2.2.2. Throw

2.3. Noise

3. INTEGRATED DESIGN

4. DESIGN PRINCIPLES

4.1. Pressure Drop

4.2. Room-by Room Supply Requirements

4.3. Return Air Design

4.4. Supply Air Outlets

4.5. Duct Layout

4.6. Duct Size

CONCLUSION

REFERENCES

Chapter 2 MEASURE GUIDELINE: SEALING AND INSULATING DUCTS IN EXISTING HOMES

DEFINITIONS

FOREWORD

ACKNOWLEDGEMENTS

PROGRESSION SUMMARY

1. INTRODUCTION

2. COST AND PERFORMANCE

2.1. Energy Savings

2.2. Cost

2.3. Cost-Performance Trade-Offs and other Solutions

2.4. Non-Energy Benefits

2.4.1. Comfort

2.4.2. HVAC Capacity

2.4.3. IAQ and Combustion Safety

3. DUCTWORK COMPONENTS

3.1. Duct Materials

3.1.1. Sheet Metal

3.1.2. Fiberglass Duct Board

3.1.3. Flex Duct

3.1.4. Building Cavities

3.2. Sealants

3.2.1. Tapes

3.2.2. Mastic

3.2.3. Aerosol Sealant

3.3. Insulation

3.3.1. Fiberglass

3.3.2. Closed-Cell Polyurethane

4. HEALTH AND SAFETY

4.1. Inspect the House and HVAC Systems

4.2. Combustion Safety Testing

4.2.1. Measure Carbon Monoxide (CO) Concentrations

4.2.2. Spillage Tests

4.2.3. Measure Draf

4.2.4. Worst Case Depressurization

4.2.5. Implications of Combustion Problems

4.3. Personal Safety and Protective Equipment

5. EVALUATING DUCT SYSTEMS

5.1. Check Airflow of System(s)

5.1.1. Temperature Rise

5.1.2. Duct Pressurization Airflow Testing

5.1.3. Flow Plate Airflow Test

5.2. Measure Duct Leakage – Duct Pressurization

5.3. Pressure Pan Test

6. DETERMINE SCOPE OF WORK

7. DUCT SEALING PROCEDURE

7.1. How to Apply Mastic

7.2. Applying Tape

7.3. Existing Duct Insulation

7.4. Furnace and Air Handle Connections

7.5. Trunk Ducts

7.6. Branch Connections

7.6.1. Flex Branches

7.6.2. Sheet Metal Branches

7.7. Branch Duct Fittings

7.8. Boot and Register Connections

7.9. Building Cavities

8. INSULATING DUCTS

8.1. Moving Ducts into Conditioned Space

8.2. Insulating Duct Wrap

8.3. Ducts Beneath Attic Insulation

9. TESTING OUT

9.1. Duct Leakage Tests

9.2. Airflow

9.3. Combustion

APPENDIX A. MEASURE IMPLEMENTATION CHECKLIST

APPENDIX B. MATERIAL SPECIFICATION

References

End Notes

Chapter 3 STRATEGY GUIDELINE: ACCURATE HEATING AND COOLING LOAD CALCULATIONS

FORWARD

DEFINITIONS

EXECUTIVE SUMMARY

INTRODUCTION

BASELINE LOAD CALCULATION

LOAD COMPONENTS

Peak Heating Load

Peak Cooling Load

Location – Design Conditions

Orientation

Building Components

Heating and Cooling System Location and Duct Leakage

Ventilation/Infiltration

RISKS ASSOCIATED WITH OVERSIZING

First Cost, Energy Costs and Durability

Comfort - Space Temperatures

Comfort - Humidity Control

LOAD DEPENDENCIES

Outdoor/Indoor Design Condition Dependencies

Building Components Dependencies

Ductwork Conditions Dependencies

Ventilation/Infiltration Conditions Dependencies

Combined Dependencies

CONCLUSION

APPENDIX A: ENHANCEMENTS TO SCOPE FOR MECHANICAL CONTRACTOR/HVAC MANUAL J DESIGNER

APPENDIX B: ACCA MANUAL J8 INPUT CHECKLIST

Insulation R-Values

Foundation

Walls

Stud Walls

Non-Stud Walls

Floors Over Unconditioned Space

Attic

Windows

Air Infiltration

Ductwork

Ventilation

Space Conditioning Zoning

Stop Work – Do Not Proceed If

References

Chapter 4 STRATEGY GUIDELINE: HVAC EQUIPMENT SIZING*

DEFINITIONS

EXECUTIVE SUMMARY

1. INTRODUCTION

2. OVERVIEW

2.1. Design Conditions

2.2. Preliminary Equipment Selection

2.3. Manufacturer Data Tables

2.4. Cooling Equipment Capacity Sensitivities

2.5. Estimated Target Cubic Feet per Minute

2.6. Efficiency Considerations

3.1. Cooling Equipment Selection

3. CHICAGO HOUSE EXAMPLE

3.2. Furnace Selection

4. ORLANDO HOUSE EXAMPLE

4.1. Air Source Heat Pump Selection

4.2. Heat Pump Cooling Capacity Selection

4.3. Heat Pump Heating Capacity Selection

CONCLUSION

References

INDEX