Heating and Cooling Load Analysis Using Revit for Building Design

Revit Analysis and Design: Heating and Cooling Load Analysis

Heating and cooling load analysis plays a crucial role in Revit’s analysis and design workflow. This process helps determine the building model’s energy requirements. Once spaces are placed and defined throughout the building model, they can be assigned to zones. Subsequently, heating and cooling load analysis can be performed to assess the energy demands of the building and evaluate spatial and zoning needs.

3D analysis model of an office building

For accurate heating and cooling load analysis, every area within the building model must have defined spaces, accounting for the entire volume. This includes unoccupied spaces such as positive pressure air supply systems, as well as calculating the volume of voids, shafts, and wall recesses. To do this, select Volume Calculation in the Area and Volume calculation dialog.

Although small gaps or void spaces may not appear as zones or spaces in plan or section views, they will be visible within the Heating and Cooling Loads analysis model dialog. This is because such spaces are included in the load analysis process and are shown in the analysis model. Refer to the volume calculation of voids, shafts, and wall grooves for more details.

The engineering phase can analyze heating and cooling requirements only if all zones and spaces in the building model correspond to that phase. Otherwise, the software will analyze only the partitions and spaces that belong to the current phases.

When working with linked models, ensure that all partitions and spaces exist in the host (local) file.

Preparing for Heating and Cooling Load Analysis

Before conducting the heating and cooling load analysis, prepare your building model by following these steps:

1. Add spaces and partitions to the model.

2. Specify area and volume settings:

a. Go to the Architecture tab and open the Room and Area panel dropdown list to access Area and Volume Calculation.

b. In the Area and Volume Calculation dialog, under the Volume Calculation tab, select Area and Volume.

Note: The Area and Volume option should always be enabled. If not selected after placing spaces, please enable it and verify the vertical range and volume of all spaces to ensure they match the design intent.

c. Under Room Area Calculation, confirm that the option for calculating volume on the wall surface layer is selected. This setting determines where volume is calculated relative to the wall.

d. Click Confirm to save these settings.

3. Set building parameters for analysis:

a. Navigate to the Analysis tab and select the Report and Detailed Table tab (Heating and Cooling Load).

b. In the Heating and Cooling Loads dialog, use the Regular tab to define parameters as needed.

4. Configure building type settings:

a. Go to the Manage tab → Settings tab → MEP Settings dropdown → Architectural/Space Type Settings.

b. In the Building/Space Type Settings dialog, select the Building Type from the list. Filters can be used to quickly find specific types.

c. Adjust parameters in the right panel according to your project requirements.

d. For each schedule (occupancy rate, lighting, and power), click the Value column to open the Detail Table Settings dialog and select or modify the detail table.

e. For Opening Time and Closing Time, click the Value column to open the Time Setting dialog, where you can specify operating hours. Use the arrows or type directly to adjust times.

Performing Heating and Cooling Load Analysis

The heating and cooling load analysis determines the building model’s heating and cooling requirements.

After placing spaces across the entire building, creating zones, and preparing the project, you can perform the analysis using the following methods:

• Use Revit’s built-in tools to calculate loads and generate reports directly within the software.
• Export the project data to a GBXML (Green Building XML) file. This opens the Export gbXML dialog, which does not calculate loads or generate reports but exports heating and cooling information, including spaces and zones. The GBXML file can then be imported into third-party load analysis software for further processing.

The GBXML format helps architectural designers understand the energy consumption characteristics of building projects by facilitating data exchange with specialized analysis tools.

Detail Table Fields for Heating and Cooling Load Analysis

The following table lists fields that can be used in detail tables to assist with project load analysis (excluding spatial attribute fields).

Importing Load Analysis from a GBXML File

If a third-party analysis outputs a GBXML file, it can be imported into Revit to aid HVAC system design:

1. Go to the Insert tab → Import panel → select Import gbXML.
2. In the Open dialog, navigate to the folder containing the GBXML file, select it, and click Open.
3. In the Select Data to Import from the GBXML File dialog, choose the categories to import into the project.

Note: After importing, the calculation parameters contained in the GBXML file will automatically be added as properties to the corresponding Revit spaces.

【 Related Skills Search 】

How to Create a Clearance Analysis Report in Revit

xuebim

Follow the latest BIM developments in the architecture industry, explore innovative building technologies, and discover cutting-edge industry insights.

← Scan with WeChat