This document discusses using Integrated Environmental Solutions (IES) modeling software for building energy analysis and HVAC load calculations. IES allows for complex HVAC system modeling, daylighting integration, and computational fluid dynamics analysis. Sample projects demonstrate how IES can be used for shading and daylighting analysis, integrated daylighting and energy optimization, and natural ventilation studies. However, the document notes that IES interfaces may not be optimal for mechanical design and output files can be difficult for non-IES users. Validation of load calculations and energy models in IES requires additional software and manual steps.

1. A User’s Perspective
on IES Modeling
Shem Heiple PE, LEED AP, GGP Amy Jarvis PE, LEED AP BD+C

2. Why IES?
 Ability to Model Complex HVAC Systems
 Sketch Up Import
 Early Stage Modeling
 HVAC Loads and Energy Modeling
 Bulk Airflow
 CFD
 Daylighting Integration

3. Sample Project ─ Shading & Daylighting
 Suncast for early
design feedback
 Radiance-daylight
analysis
 Radiance integrated
with energy model
 Output daylight file for
sensor location
 Daylight control profile

4. Integrated Daylighting & Energy Optimization
ARCHITECTURAL
INFORMATION
DAYLIGHTING
MODEL
DAYLIGHTING
ANALYSIS
ENERGY MODEL:
EQUEST
ENERGY
ANALYSIS
Daylighting Results

5. Integrated Daylighting & Energy Optimization
ARCHITECTURAL
INFORMATION
IES MODEL
DAYLIGHTING
ANALYSIS:
IES MODEL
Daylighting Results
ENERGY
ANALYSIS

6. Daylighting (RadianceIES)

7. Daylighting (RadianceIES)

8. Daylighting (RadianceIES)

9. Daylighting (RadianceIES)

10. Daylighting Optimization
Daylighting (RadianceIES)

11. Daylighting Analysis
Daylighting Results
Energy Analysis
Daylighting (RadianceIES)

12. Building Shading Analysis

13. Shading Options Comparison

14. Sample Project–CFD
 Applications
 No transient model
 Creates surface
boundary conditions
based on energy model
and solar analysis
 Natural ventilation and
thermal comfort
 Wind studies

15. HVAC Load Calculations
ARCHITECTURAL
INFORMATION
RESULTS
RESULTS
RECONCILIATION
HVAC LOAD
CALCULATIONS
ENERGY
MODELING
TRANE
TRACE
EQUEST
ARCHITECTURAL
INFORMATION
RESULTSIES
HVAC LOAD
CALCULATIONS
ENERGY
MODELING

16. HVAC Load Calculations
 Multiple load calculation methods used
in the industry.
 eQuest: Weighting Factor Method (WF)
 Uses 8760 file for peak conditions.
 IES-VE and EnergyPlus: Heat Balance
Method (HB)–most accurate.
 Trace: Radiant Time Series (RTS)–
Other methods available.
 Results differing as much 40% when
applied to the same building.

17. DOE2 Auto Sizing Comparison
BUILDING TYPE
DOE2 COOLING
(BTU/HR/SF)
DESIGN COOLING
(BTU/HR/SF)
PERCENT
DIFFERENCE
FROM DOE2
LOAD
CALCULATION
SOFTWARE
Office 20.6 24.4 15.7% CHVAC (Elite)
Gov Office (24/7) 35.2 29.8 -18.2% Trace
Police Station 11.3 14.3 20.7% CHVAC (Elite)
Community College 27.7 27.3 -1.4% CHVAC (Elite)
Office (PUD) 25.4 19.0 -34.2% CHVAC (Elite)

18. Using IES for HVAC Load Calculations
 Interface and reports are designed for energy
analyses, not for mechanical design
 Energy analyst and mechanical designer must
work together
 High level of input complexity for load calculations
 Inputs for load calculations and energy model not
clearly defined
 Load profiles and diversity must be manually reset

19. IES HVAC Load Output Files
 Difficult to understand by non-IES user
 Some information needed for engineering
validation not provided
 Use of Vista required for load validation

20. System Sizing Plant Loads

21. Model Validation Using Vista

22. Model Validation Using Vista

23. Model Validation Using Vista

24. Energy Performance Verification
 No automated output report
 Only report created by PRM navigator
 Input verification can be time consuming
 Limited reports for fan power or total
airflow–must sum up individually
 Time consuming to QA/QC
 Revit integration

25. Thank you!
shemh @ interfaceeng.com amy.jarvis @ zgf.com
Shem Heiple PE, LEED AP, GGP Amy Jarvis PE, LEED AP BD+C