Revit Integration - Complete BIM-to-Calculation Workflow

<h3>What is BIM-Based MEP Engineering?</h3><p>Building Information Modeling (BIM) has transformed how MEP engineers approach design. Rather than working with 2D drawings, BIM provides a rich 3D model containing spatial data, material properties, and system relationships.</p><h4>Key Benefits</h4><table class="table table-bordered"><thead><tr><th>Benefit</th><th>Description</th><th>Impact</th></tr></thead><tbody><tr><td><b>Automatic Data Extraction</b></td><td>Spaces, walls, windows extracted directly from Revit</td><td>Eliminates 90% of manual data entry</td></tr><tr><td><b>Real-time Synchronization</b></td><td>Changes in Revit automatically reflected</td><td>Design iterations take minutes</td></tr><tr><td><b>Bidirectional Updates</b></td><td>Results pushed back to Revit parameters</td><td>Schedules and tags stay current</td></tr><tr><td><b>Thermal Bridge Analysis</b></td><td>Automatic detection of junctions, corners</td><td>10-30% more accurate envelope loads</td></tr></tbody></table><h4>Integration Architecture</h4><ol><li><b>Revit Add-in (C#/.NET)</b> - Extracts model data and manages synchronization</li><li><b>JSON Data Exchange</b> - Portable format containing all model information</li><li><b>WebSocket Connection</b> - Real-time bidirectional communication on port 8765</li><li><b>Desktop Application (Python)</b> - Performs calculations and displays results</li></ol><h4>Supported Revit Versions</h4><p>The add-in supports <b>Autodesk Revit 2022, 2023, 2024, and 2025</b> with version-specific manifest files.</p><h4>Data Categories Extracted</h4><ul><li><b>MEP Spaces/Rooms:</b> Area, volume, height, occupancy, lighting loads, equipment loads</li><li><b>Walls:</b> Area, orientation, U-value (calculated from layers), thermal bridges</li><li><b>Windows:</b> Area, U-value, SHGC, frame type, shading devices</li><li><b>Doors:</b> Area, U-value (exterior only)</li><li><b>Roofs:</b> Area, U-value, insulation type</li><li><b>Floors:</b> Exposed/ground contact areas, U-value</li><li><b>MEP Equipment:</b> Capacities, airflows, system assignments</li><li><b>Duct Systems:</b> Sizes, lengths, flow rates, system types</li><li><b>Pipe Systems:</b> Sizes, lengths, system types</li><li><b>Plumbing Fixtures:</b> Fixture counts, fixture units</li></ul>

<h3>System Requirements</h3><table class="table table-bordered"><tr><td><b>Operating System</b></td><td>Windows 10 or Windows 11 (64-bit)</td></tr><tr><td><b>Revit Version</b></td><td>Autodesk Revit 2022, 2023, 2024, or 2025</td></tr><tr><td><b>.NET Framework</b></td><td>4.8 or later (included with Revit)</td></tr><tr><td><b>Disk Space</b></td><td>Approximately 50 MB for add-in files</td></tr><tr><td><b>Network</b></td><td>Port 8765 (WebSocket) for Live Sync feature</td></tr></table><h3>Installation Steps</h3><h4>Step 1: Download the Add-in Package</h4><ol><li>Navigate to the Downloads page in the J∆S Engineering Suite portal</li><li>Click "Revit Add-in" to download <code>MEP_Revit_Addin.zip</code></li><li>Extract the ZIP file to a temporary location</li></ol><h4>Step 2: Run the Installer (Recommended)</h4><ol><li>Double-click <code>MEP_Revit_Addin_Setup.exe</code></li><li>Select the Revit versions you want to install for (2022, 2023, 2024, 2025)</li><li>Click "Install" and wait for completion</li><li>Restart Revit if it was running</li></ol><h4>Step 2 (Alternative): Manual Installation</h4><pre><code>1. Copy "MEPDesignSuite.dll" to: C:\ProgramData\Autodesk\Revit\Addins\[YEAR]\

2. Copy the appropriate manifest file: - For Revit 2022: MEPDesignSuite_2022.addin - For Revit 2023: MEPDesignSuite_2023.addin - For Revit 2024: MEPDesignSuite_2024.addin - For Revit 2025: MEPDesignSuite_2025.addin Rename to: MEPDesignSuite.addin

3. Copy the "Resources" folder to the same location</code></pre><h4>Step 3: Verify Installation</h4><ol><li>Launch Autodesk Revit</li><li>Open any project (or create a new one)</li><li>Look for the <b>"JS Engineering Suite"</b> tab in the ribbon</li><li>You should see panels: Design Suite, Coordination, Tools, MEP Tools, Data, Model, Sheets, Export, Analysis, Help</li></ol><h4>Step 4: Configure Firewall (For Live Sync)</h4><p>The Live Sync feature uses WebSocket communication on port 8765. To configure Windows Firewall:</p><ol><li>Open Windows Defender Firewall with Advanced Security</li><li>Click "Inbound Rules" then "New Rule"</li><li>Select "Port" then Next</li><li>Select "TCP" and enter "8765" then Next</li><li>Select "Allow the connection" then Next</li><li>Check all profiles (Domain, Private, Public) then Next</li><li>Name: "J∆S Engineering Suite Live Sync" then Finish</li></ol><h4>Troubleshooting Installation</h4><table class="table table-bordered"><thead><tr><th>Problem</th><th>Cause</th><th>Solution</th></tr></thead><tbody><tr><td>Tab does not appear</td><td>Manifest not loaded</td><td>Check .addin file is in correct folder; verify XML syntax</td></tr><tr><td>"Could not load assembly"</td><td>Wrong Revit version</td><td>Use correct manifest for your Revit year</td></tr><tr><td>Missing icons</td><td>Resources folder missing</td><td>Copy Resources folder to Addins directory</td></tr><tr><td>Permission denied</td><td>Admin rights needed</td><td>Run installer as Administrator</td></tr></tbody></table>

<h3>Ribbon Tab Overview</h3><p>The "JS Engineering Suite" tab contains 10 panels organized by function:</p><h4>Panel 1: Design Suite</h4><table class="table table-bordered"><tr><td width="180"><b>Launch MEP Design Suite</b></td><td>Opens the full desktop application with current Revit project data automatically loaded. This is your primary entry point for calculations.</td></tr><tr><td><b>Import Results</b></td><td>After running calculations, imports results back into Revit space parameters (Calculated Cooling Load, Heating Load, Supply Airflow, etc.)</td></tr></table><h4>Panel 2: Coordination</h4><table class="table table-bordered"><tr><td width="180"><b>Clash Detection</b></td><td>Runs clash detection between MEP elements and structure, including linked models</td></tr><tr><td><b>Check Selected</b></td><td>Runs clash detection only on currently selected elements</td></tr><tr><td><b>Clash Browser</b></td><td>Advanced clash browser with grouping by severity/category/level, navigation, zoom-to, and CSV export</td></tr></table><h4>Panel 3: Tools</h4><table class="table table-bordered"><tr><td width="180"><b>Element Finder</b></td><td>OneFilter-style element search with parameter-based filtering, select/isolate/hide functions</td></tr><tr><td><b>Parameter Editor</b></td><td>Bulk parameter editing with find/replace, prefix/suffix, and increment functions</td></tr><tr><td><b>Family Browser</b></td><td>Browse and manage loaded families, delete unused, export to RFA</td></tr></table><h4>Panel 4: MEP Tools</h4><table class="table table-bordered"><tr><td width="180"><b>Hanger Placement</b></td><td>Automatically place hangers/supports along duct and pipe runs at specified intervals</td></tr><tr><td><b>Elevation Adjust</b></td><td>Bulk adjust elevations of selected MEP elements (relative or absolute)</td></tr><tr><td><b>Pipe Slope</b></td><td>Analyze and verify pipe slopes, show rise/run/percentage</td></tr><tr><td><b>Insulation Calculator</b></td><td>Calculate insulation quantities for ducts and pipes by size</td></tr><tr><td><b>System Analyzer</b></td><td>Find disconnected elements, system summaries, connection issues</td></tr></table><h4>Panels 5-10</h4><p>Additional panels provide: Data (export/import schedules, CSV, bulk update), Model (purge, cleanup, links), Sheets (sheet set manager), Export (batch PDF/DWG, IFC, gbXML, JSON), Analysis (lighting, envelope, U-value, duct/pipe sizing), and Help.</p><h4>Keyboard Shortcuts</h4><p>Assign shortcuts through Revit Keyboard Shortcuts dialog:</p><ul><li><code>JL</code> - Launch MEP Design Suite</li><li><code>JI</code> - Import Results</li><li><code>JC</code> - Clash Detection</li><li><code>JE</code> - Export JSON</li></ul>

<h3>Rooms vs. MEP Spaces</h3><p>Revit has two spatial element types, and understanding the difference is critical for MEP calculations:</p><table class="table table-bordered"><thead><tr><th>Feature</th><th>Rooms</th><th>MEP Spaces</th></tr></thead><tbody><tr><td>Primary Use</td><td>Architectural space planning, finish schedules</td><td>HVAC/MEP engineering analysis</td></tr><tr><td>Thermal Parameters</td><td>Limited</td><td>Full thermal properties (loads, ASHRAE settings)</td></tr><tr><td>Zone Air Settings</td><td>Not available</td><td>Heating/Cooling setpoints, ventilation</td></tr><tr><td>Occupancy Parameters</td><td>Basic</td><td>People count, ventilation per person/area</td></tr><tr><td>Equipment Loads</td><td>Not available</td><td>Equipment power density, schedules</td></tr><tr><td>Lighting Loads</td><td>Not available</td><td>Lighting power density, schedules</td></tr></tbody></table><p><b>Recommendation:</b> Always use MEP Spaces for projects requiring HVAC calculations. If your model only has Rooms, create MEP Spaces from Room boundaries using Analyze - Spaces - Create Spaces - New Spaces from Rooms.</p><h3>Preparing Your Model for Export</h3><h4>Step 1: Verify Space Boundaries</h4><ul><li>Ensure all spaces are properly bounded (not redundant or unenclosed)</li><li>Check for overlapping spaces using Analyze - Space - Check Spaces</li><li>Verify upper and lower limits are set correctly for accurate volumes</li></ul><h4>Step 2: Assign Space Types</h4><p>Each space should have a space type that determines default load assumptions:</p><pre><code>Common Space Types for HVAC: - Office - Enclosed (10-15 occupants/1000 SF) - Office - Open Plan (5-7 occupants/1000 SF) - Conference Room (50 occupants/1000 SF) - Lobby (10 occupants/1000 SF) - Laboratory (10 occupants/1000 SF) - Healthcare - Patient Room (2 people per room)</code></pre><h4>Step 3: Set Key Parameters</h4><table class="table table-bordered"><thead><tr><th>Parameter</th><th>Description</th><th>Impact on Calculations</th></tr></thead><tbody><tr><td>Number of People</td><td>Design occupancy</td><td>Sensible/latent people loads, ASHRAE 62.1 ventilation</td></tr><tr><td>Lighting Load</td><td>Watts or W/SF</td><td>Cooling load from lighting heat gain</td></tr><tr><td>Power Load (Equipment)</td><td>Watts or W/SF</td><td>Cooling load from equipment heat gain</td></tr><tr><td>Space Type</td><td>ASHRAE space classification</td><td>Default ventilation rates, schedules</td></tr></tbody></table><h3>Export Methods</h3><h4>Method 1: Launch MEP Design Suite (Recommended)</h4><p>Click "Launch MEP Design Suite" in the Design Suite panel. This extracts all model data automatically, creates a temporary JSON file, launches the desktop application with data pre-loaded, and establishes WebSocket connection for live sync.</p><h4>Method 2: Export JSON File</h4><p>Click "Export JSON" in the Export panel to create a standalone .json file you can open later, share with team members, or archive for project records.</p><h4>Method 3: Export gbXML</h4><p>Click "Export gbXML" for compatibility with other energy analysis tools (EnergyPlus, eQUEST, TRACE).</p>

<h3>Overview of MEP Data Extraction</h3><p>The add-in extracts comprehensive MEP system data that allows the desktop application to verify sized ductwork against calculated airflows, check pipe sizes against flow requirements, compare equipment capacities to calculated loads, and calculate fixture unit totals per IPC.</p><h3>Duct System Extraction</h3><table class="table table-bordered"><thead><tr><th>Data Element</th><th>Source</th><th>Use in Calculations</th></tr></thead><tbody><tr><td>System Type</td><td>MEP System</td><td>Supply/Return/Exhaust classification</td></tr><tr><td>Flow Rate</td><td>Duct Flow parameter</td><td>Velocity verification</td></tr><tr><td>Size</td><td>Width/Height/Diameter</td><td>Pressure drop calculation</td></tr><tr><td>Length</td><td>Geometry</td><td>System total equivalent length</td></tr><tr><td>Insulation</td><td>Insulation type/thickness</td><td>Heat gain/loss in duct</td></tr></tbody></table><h4>Recommended Duct Velocities (FPM)</h4><pre><code>Application Supply Return Residential 600-900 400-600 Office/Public 1000-1500 800-1200 Industrial 1200-2000 1000-1500 Main Duct 1500-2500 1200-1800 Branch Duct 800-1200 600-1000</code></pre><h3>Pipe System Extraction</h3><table class="table table-bordered"><thead><tr><th>Data Element</th><th>Source</th><th>Use in Calculations</th></tr></thead><tbody><tr><td>System Type</td><td>Piping System</td><td>Hydronic/Plumbing/Gas classification</td></tr><tr><td>Size</td><td>Diameter parameter</td><td>Velocity/pressure drop</td></tr><tr><td>Flow</td><td>Flow parameter</td><td>GPM verification</td></tr><tr><td>Material</td><td>Pipe type</td><td>Friction factor (Hazen-Williams C)</td></tr></tbody></table><h4>Hazen-Williams Coefficients</h4><pre><code>Material C Value Copper, new 140 Steel, new 120 PVC/CPVC 150 PEX 150</code></pre><h3>Mechanical Equipment Extraction</h3><p>Equipment data including AHU cooling/heating capacity, supply airflow, outdoor air, motor HP, and static pressure is extracted. Terminal units (VAV, FCU) include maximum/minimum airflow and reheat capacity.</p><h3>Plumbing Fixture Extraction</h3><table class="table table-bordered"><thead><tr><th>Fixture Type</th><th>Water Supply FU</th><th>DFU</th></tr></thead><tbody><tr><td>Water Closet (flush valve)</td><td>10</td><td>4</td></tr><tr><td>Water Closet (tank)</td><td>5</td><td>4</td></tr><tr><td>Lavatory (private)</td><td>1</td><td>1</td></tr><tr><td>Lavatory (public)</td><td>2</td><td>2</td></tr><tr><td>Kitchen Sink (commercial)</td><td>4</td><td>3</td></tr></tbody></table><h3>Export Best Practices</h3><ol><li><b>Assign systems correctly</b> - Ensure all ducts and pipes are connected to systems</li><li><b>Set flow parameters</b> - Enter design flows for sizing verification</li><li><b>Tag equipment</b> - Use Mark parameter for identification</li><li><b>Connect to spaces</b> - Link terminal units to served spaces</li></ol>

<h3>The Data Validation Service</h3><p>Before any export, the add-in runs comprehensive validation checks through the DataValidationService. This ensures your model data will produce accurate calculations.</p><h4>Validation Categories</h4><ol><li><b>Project Information</b> - Name, location, climate zone, building type</li><li><b>Spaces</b> - Boundaries, areas, volumes, heights, thermal parameters</li><li><b>Walls</b> - Compound structure, insulation, materials</li><li><b>Windows</b> - U-value, SHGC, dimensions</li><li><b>Roofs</b> - Structure, insulation</li><li><b>MEP Equipment</b> - Capacities, marks/tags</li><li><b>Plumbing</b> - Fixture units</li><li><b>Ducts</b> - System assignments, flow rates</li><li><b>Pipes</b> - System assignments</li><li><b>Systems</b> - Supply/return/exhaust completeness</li></ol><h3>Issue Severity Levels</h3><table class="table table-bordered"><thead><tr><th>Level</th><th>Impact</th><th>Action Required</th></tr></thead><tbody><tr><td><span class="badge bg-danger">Critical</span></td><td>Export may fail or produce invalid results</td><td>Must fix before export</td></tr><tr><td><span class="badge bg-warning">Warning</span></td><td>Results may be inaccurate</td><td>Should review and fix</td></tr><tr><td><span class="badge bg-info">Info</span></td><td>Using default values</td><td>Optional improvement</td></tr></tbody></table><h3>Quality Score Calculation</h3><pre><code>Quality Score (0-100): - Start with 100 points - Deduct 10 points per Critical issue - Deduct 3 points per Warning - Deduct 1 point per Info

Score Interpretation: 90-100: Excellent - Ready for export 70-89: Good - Review warnings 50-69: Fair - Fix critical issues Below 50: Poor - Significant model issues</code></pre><h3>Common Validation Issues and Solutions</h3><table class="table table-bordered"><thead><tr><th>Issue</th><th>Solution</th></tr></thead><tbody><tr><td>No MEP Spaces found</td><td>Analyze - Spaces - New Spaces from Rooms</td></tr><tr><td>Space unbounded</td><td>Check room-bounding elements and limits</td></tr><tr><td>No exterior walls found</td><td>Edit Type - Function - Exterior</td></tr><tr><td>Material has no thermal conductivity</td><td>Manage - Materials - Thermal Asset</td></tr><tr><td>Window SHGC missing</td><td>Add "SHGC" type parameter</td></tr></tbody></table><h3>Smart Defaults</h3><p>When data is missing, the add-in applies ASHRAE-based defaults:</p><pre><code>Parameter Default Value Occupancy (office) 5 people/1000 SF Lighting (office) 0.90 W/SF Equipment (office) 0.75 W/SF Ventilation (office) 5 CFM/person + 0.06/SF Wall U-value 0.064 BTU/hr-ft2-F Roof U-value 0.039 BTU/hr-ft2-F Window U-value 0.42 BTU/hr-ft2-F Window SHGC 0.25</code></pre>

<h3>The Calculation-to-Revit Workflow</h3><pre><code>1. Export model data (Launch MEP Design Suite) 2. Review/adjust in desktop application 3. Run calculations 4. Click "Sync to Revit" in desktop app 5. In Revit, click "Import Results" 6. Review and confirm changes 7. Parameters updated in Revit model</code></pre><h3>Parameters Updated by Import</h3><table class="table table-bordered"><thead><tr><th>Revit Parameter</th><th>Calculation Result</th><th>Units</th></tr></thead><tbody><tr><td>Calculated Cooling Load</td><td>Peak cooling load</td><td>BTU/hr</td></tr><tr><td>Calculated Heating Load</td><td>Peak heating load</td><td>BTU/hr</td></tr><tr><td>Design Supply Airflow</td><td>Required supply CFM</td><td>CFM</td></tr><tr><td>Calculated Ventilation</td><td>ASHRAE 62.1 outdoor air</td><td>CFM</td></tr><tr><td>People Load</td><td>Sensible people load</td><td>BTU/hr</td></tr><tr><td>Lighting Load</td><td>Lighting heat gain</td><td>BTU/hr</td></tr><tr><td>Equipment Load</td><td>Equipment heat gain</td><td>BTU/hr</td></tr></tbody></table><h3>Using Import Results</h3><p>In the desktop application, ensure you have reviewed all space data for accuracy, verified weather/design conditions, run the load calculations, and reviewed results for reasonableness. Then click "Sync to Revit" and select which data to sync.</p><p>In Revit, click "Import Results" in the Design Suite panel, review the preview dialog showing all changes, optionally deselect specific spaces or parameters, and click "Apply Changes".</p><h3>Import Preview Dialog</h3><pre><code>Import Results Preview

Changes to apply: 45 spaces

[x] Office 101 Cooling Load: 12,500 to 14,250 BTU/hr (+14%) Heating Load: 8,200 to 7,850 BTU/hr (-4%) Supply Air: 350 to 400 CFM (+14%)

Summary: Total Cooling: 450,000 to 512,500 BTU/hr (+14%) Total Heating: 280,000 to 265,000 BTU/hr (-5%)</code></pre><h3>Handling Conflicts</h3><ul><li><b>Override</b> - Replace Revit values with calculated values</li><li><b>Skip</b> - Keep existing Revit values</li><li><b>Maximum</b> - Use the larger value (conservative)</li><li><b>Minimum</b> - Use the smaller value</li></ul><h3>Transaction Handling</h3><p>All changes are wrapped in a Revit transaction named "Apply MEP Calculation Results". All changes are applied atomically, you can Undo the entire import with Ctrl+Z, and worksharing users see values after sync-to-central.</p>

<h3>What is Live Sync?</h3><p>Live Sync provides real-time bidirectional communication between Revit and the desktop application using WebSocket technology. When enabled, changes in Revit are automatically detected and sent to the desktop app, calculation results can be pushed back instantly, no manual export/import steps are required, and design iterations become nearly instantaneous.</p><h3>Architecture</h3><pre><code>Autodesk Revit WebSocket (Port 8765) J∆S Engineering Suite | | Add-in -------- Handshake, Model Updates ---------> Live Sync Server | | | <------- Calculation Results, Updates -------- |</code></pre><h3>Enabling Live Sync</h3><h4>Step 1: Start the Desktop Application</h4><p>Launch J∆S Engineering Suite desktop application. The WebSocket server starts automatically on port 8765.</p><h4>Step 2: Connect from Revit</h4><p>Click "Launch MEP Design Suite". The add-in will extract initial model data, connect to ws://localhost:8765, send handshake with project information, and begin monitoring for changes.</p><h4>Step 3: Verify Connection</h4><ul><li><span style="color:green">Green</span> <b>Connected</b> - Active WebSocket connection</li><li><span style="color:orange">Orange</span> <b>Syncing</b> - Data transfer in progress</li><li><span style="color:red">Red</span> <b>Disconnected</b> - No connection (will auto-reconnect)</li></ul><h3>Categories Tracked for Auto-Sync</h3><pre><code>Tracked Categories: - OST_MEPSpaces (MEP Spaces) - OST_Rooms (Architectural Rooms) - OST_Walls, OST_Windows, OST_Doors - OST_Roofs, OST_Floors - OST_MechanicalEquipment - OST_DuctTerminal, OST_DuctCurves - OST_PipeCurves, OST_PlumbingFixtures - OST_ElectricalEquipment</code></pre><h3>Message Types</h3><table class="table table-bordered"><thead><tr><th>Message Type</th><th>Direction</th><th>Description</th></tr></thead><tbody><tr><td><code>handshake</code></td><td>Revit to Desktop</td><td>Initial connection with project info</td></tr><tr><td><code>model_update</code></td><td>Revit to Desktop</td><td>Incremental changes</td></tr><tr><td><code>full_model</code></td><td>Revit to Desktop</td><td>Complete model data</td></tr><tr><td><code>calculation_results</code></td><td>Desktop to Revit</td><td>Load calculation results</td></tr></tbody></table><h3>Handling Disconnections</h3><p>If the connection is lost, the add-in automatically attempts reconnection every 5 seconds, pending changes are queued, and on reconnect queued changes are sent.</p><h3>Performance Considerations</h3><ul><li><b>Large models:</b> Initial sync may take 30-60 seconds for 10,000+ elements</li><li><b>Frequent changes:</b> Changes are batched and debounced (100ms)</li><li><b>Network:</b> Localhost connection recommended for performance</li></ul>

<h3>Understanding Thermal Bridges</h3><p>Thermal bridges are localized areas where heat flow is significantly higher than through surrounding components. They account for 10-30% of total envelope heat loss in modern buildings.</p><h4>Types of Thermal Bridges</h4><table class="table table-bordered"><thead><tr><th>Type</th><th>Examples</th><th>Psi Value Range</th></tr></thead><tbody><tr><td><b>Geometric</b></td><td>External corners, wall-floor junctions</td><td>0.03-0.20 BTU/hr-ft-F</td></tr><tr><td><b>Structural</b></td><td>Concrete balconies, steel columns, shelf angles</td><td>0.20-0.80 BTU/hr-ft-F</td></tr><tr><td><b>Material</b></td><td>Window frames, door frames</td><td>0.02-0.05 BTU/hr-ft-F</td></tr><tr><td><b>Systematic</b></td><td>Wall ties, fasteners (point bridges)</td><td>0.001-0.01 BTU/hr-F each</td></tr></tbody></table><h3>Thermal Bridge Extraction</h3><p>The ThermalBridgeService automatically extracts wall corners (external/internal), wall-floor junctions, wall-roof junctions, window perimeters (sill, head, jambs), door perimeters, balcony slabs, parapets, and shelf angles.</p><h3>U-Value Analysis Service</h3><p>The AssemblyUValueService calculates accurate U-values from Revit compound structures by:</p><ol><li>Extracting each layer from compound structure</li><li>Looking up material thermal conductivity from Revit thermal assets</li><li>Calculating layer R-values: R = thickness / conductivity</li><li>Adding surface film resistances per ASHRAE</li><li>Summing total R-value and converting to U-value</li></ol><h4>Surface Film Resistances (ASHRAE)</h4><pre><code>Location R-Value (hr-ft2-F/BTU) Interior, still air (vertical) 0.68 Interior, heat flow up (roof) 0.61 Interior, heat flow down (floor) 0.92 Exterior, 15 mph wind (winter) 0.17 Air cavity (3/4" - 4") 0.91</code></pre><h3>ASHRAE 90.1-2022 Compliance</h3><p>U-values are checked against prescriptive requirements by climate zone:</p><pre><code>Maximum U-Values by Climate Zone: CZ Walls Roofs Floors 1 0.124 0.048 0.107 2 0.124 0.048 0.107 3 0.084 0.048 0.071 4 0.064 0.039 0.052 5 0.064 0.039 0.052 6 0.064 0.032 0.052 7 0.064 0.028 0.052 8 0.064 0.028 0.052</code></pre><h3>Best Practices</h3><ol><li><b>Assign thermal assets</b> to all materials (Manage - Materials - Thermal tab)</li><li><b>Use correct layer functions</b> in compound structures</li><li><b>Model thermal breaks</b> in balcony slabs and penetrations</li><li><b>Review thermal bridge summary</b> for high-impact items</li></ol>

<h3>Common Issues and Solutions</h3><h4>Installation Issues</h4><table class="table table-bordered"><thead><tr><th>Problem</th><th>Solution</th></tr></thead><tbody><tr><td>Tab does not appear</td><td>Verify .addin file in correct folder; check Revit version matches manifest; look in Add-Ins tab for disabled add-ins</td></tr><tr><td>Assembly load failure</td><td>Ensure all DLLs present; unblock downloaded files; run as Administrator once; verify .NET 4.8</td></tr><tr><td>Commands disabled</td><td>Open a project document (not family); check license status</td></tr></tbody></table><h4>Data Export Issues</h4><table class="table table-bordered"><thead><tr><th>Problem</th><th>Solution</th></tr></thead><tbody><tr><td>No spaces exported</td><td>Create MEP Spaces; ensure bounded; check phase matches view</td></tr><tr><td>Missing wall U-values</td><td>Define compound structure; assign thermal assets; set Function to Exterior</td></tr><tr><td>Window SHGC = 0</td><td>Add "SHGC" parameter to window families; set reasonable value (0.20-0.40)</td></tr></tbody></table><h4>Live Sync Issues</h4><table class="table table-bordered"><thead><tr><th>Problem</th><th>Solution</th></tr></thead><tbody><tr><td>Cannot connect</td><td>Launch desktop app first; check firewall allows port 8765</td></tr><tr><td>Changes not syncing</td><td>Verify AutoSync enabled; check category in sync list; force full sync (save document)</td></tr></tbody></table><h3>Model Preparation Best Practices</h3><ol><li><b>Use MEP Spaces, not Rooms</b> - MEP Spaces contain thermal parameters</li><li><b>Set Accurate Project Location</b> - Latitude/longitude affects solar calculations</li><li><b>Define Compound Structures</b> - All exterior elements need layer definitions</li><li><b>Assign Thermal Assets</b> - Materials need thermal conductivity values</li><li><b>Set Window Performance Data</b> - Add U-value and SHGC parameters</li><li><b>Define Space Types</b> - Determines default ASHRAE 62.1 ventilation</li></ol><h3>Team Workflow Recommendations</h3><h4>For Workshared Models</h4><ul><li>Each user can run their own Live Sync session</li><li>Results imported to local model, then synced to central</li><li>Coordinate to avoid simultaneous imports of same spaces</li><li>Use worksets to control who can edit space parameters</li></ul><h4>BIM Coordination Workflow</h4><pre><code>1. Architect completes space layout 2. MEP Engineer creates MEP Spaces from Rooms 3. MEP Engineer exports to J∆S Engineering Suite 4. Run load calculations 5. Size systems and select equipment 6. Import results back to Revit 7. Model ductwork and piping 8. Run clash detection 9. Iterate as design changes</code></pre><h3>Maintaining Calculation Accuracy</h3><ol><li><b>Re-export after major changes</b> - When walls move, windows change, or spaces modify</li><li><b>Verify totals match</b> - Compare building area in Revit vs desktop app</li><li><b>Review validation report</b> - Address warnings before finalizing</li><li><b>Document assumptions</b> - Record manual adjustments</li><li><b>Archive calculation sets</b> - Save JSON exports at SD, DD, CD milestones</li></ol><h3>Getting Help</h3><ul><li><b>In-app Help:</b> Click "About" for version info and links</li><li><b>Documentation:</b> Full user guides in Training section</li><li><b>Support:</b> Submit tickets through web portal</li><li><b>Log Files:</b> Revit journal files contain add-in error details</li></ul>