Related Resources: HVAC

Accurate Heating and Cooling Load Calculations

White Papers, Engineering Documents and Specifications

This resource requires a Premium Membership

Open: Strategy Guideline: Accurate Heating and Cooling Load Calculations

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
References
Appendix A: Enhancements to Scope for Mechanical Contractor/HVAC Manual J Designer
Appendix B: ACCA Manual J8 Input Checklist

List of Figures
Figure 1. Results – Orlando House Manipulated Outdoor/Indoor Design Conditions
Figure 2. Results – Orlando House Combined Manipulations
Figure 3. Residential HVAC Design Process
Figure 4. Typical 2223 ft2 One Story House
Figure 5. Heat Loss Locations
Figure 6. Heat Gain Locations
Figure 7. ASHRAE Winter and Summer Comfort Zones
Figure 8. Outdoor cooling bin hours in Orlando, FL
Figure 9. Building Orientation 13
Figure 10. Building Orientation Cooling Load
Figure 11. Test for Adequate Exposure Diversity – Pass
Figure 12. Test for Adequate Exposure Diversity – Fail
Figure 13. Chicago House Change in Loads, Manipulated Outdoor/Indoor Design Conditions
Figure 14. Orlando House Change in Loads, Manipulated Outdoor/Indoor Design Conditions
Figure 15. Chicago House Change in Loads, Building Component Manipulations
Figure 16. Orlando House Change in Loads, Building Component Manipulations
Figure 17. Orlando House Change in Loads, Ductwork Conditions Manipulations
Figure 18. Chicago House Change in Loads, Ventilation/Infiltration Manipulations
Figure 19. Orlando House Change in Loads, Ventilation/Infiltration Manipulations
Figure 20. Chicago House Change in Loads, Combined Manipulations
Figure 21. Orlando House Change in Loads, Combined Manipulations
* Unless otherwise noted, all Figures were created by IBACOS.

List of Tables
Table 1. Baseline Model Parameters
Table 2. Baseline Calculated Loads Using ACCA MJ8
Table 3. Outdoor Design Conditions for the United States - Manual J Version 8, Table 1A
Table 4. Chicago House Manipulated Outdoor/Indoor Design Conditions
Table 5. Orlando House Manipulated Outdoor/Indoor Design Conditions
Table 6. Results – Chicago House Manipulated Outdoor/Indoor Design Conditions
Table 7. Results - Orlando House Manipulated Outdoor/Indoor Design Conditions
Table 8. Chicago House Building Component Manipulations
Table 9. Orlando House Building Component Manipulations
Table 10. Results - Chicago House Building Component Manipulations
Table 11. Results - Orlando House Building Component Manipulations
Table 12. Orlando House Ductwork Conditions Manipulations
Table 13. Results - Orlando House Ductwork Conditions Manipulations
Table 14. Chicago House Ventilation/Infiltration Manipulations
Table 15. Orlando House Ventilation/Infiltration Manipulations
Table 16. Results - Chicago House Ventilation / Infiltration
Table 17. Results – Orlando House Ventilation/Infiltration
Table 18. Results - Chicago House Combined Manipulations
Table 19. Results - Orlando House Combined Manipulations Results