The Load Calculation and HVAC Equipment Sizing navigator takes you through only the IESVE features needed for heating and cooling load calculations and HVAC equipment sizing. The Navigator is arranged semi-chronologically. With the categories collapsed, work down the list from top to bottom, expanding each category in turn. Some categories offer more than one route to the same result. Where they do, use whichever suits your workflow, the outcome is the same.
Step 1: Open IESVE Software and create a new project or open an existing one.
Step 2: Select the Navigators tab in the applications pane.
Step 3: Select the drop-down in the upper left corner which displays all available navigators.
Step 4: Locate and select the (+) button next to HVAC Design Engineering.
Step 5: Locate and select the Loads Calculation and HVAC Equipment Sizing navigator.
Upon selecting the navigator, the following outline will appear:
Opens a module (ApLocate) used to input the geographical location and climate. The module contains four tabs:
Location and Site Data (Tab 1): Select location and review latitude and longitude, define daylight
savings time, and specify site conditions such as ground reflectance, outdoor
CO2 concentration and reference air density.
Design Weather Data (Tab 2): Consistent with ASHRAE recommended practices in the Handbook of Fundamentals, specify heating design condition (one moment in time) and the hourly design cooling maximum and minimum dry-bulb and wet-bulb temperatures.
Simulation Weather Data (Tab 3): Simulation weather data is not required for completion of this navigator, however, it may prove useful to design engineers for designing different controls sequence of operations for HVAC systems.
Simulation Calendar (Tab 4): If planning to user simulation, this tab is used to define the calendar including leap year and holidays.
Specify True North for the project. Solar position and wind direction are both referenced to this setting, so an incorrect orientation carries through into every load calculation and simulation.
Creates a report using the inputs assigned in the Site, Location, and Climate and Building Orientation steps prior.
The Model Geometry segment is a milestone step containing a note that a geometry must be created for the following steps. Review the user guide ModelIT sections and review online training for creating and importing building geometry.
When selected, the browser switches to the HVAC Zones and Zone Groups organization.
To create a new system grouping, right-click in the white space and select New Zone Group. Alternatively, select the grid of nine tiles in the top left corner to open the dialog for creating zone groups and zones.
Once the zones are set up, drag rooms from the No ApacheHVAC System group onto the zones they belong to.
Creates a 3D view of the zones or zone groups. The view defaults to zone groups. To see individual zones instead, select Zones in the list on the right.
Opens a dialog that can used to create Exterior Walls, Roofs, and Floors using the categories organized within ASHRAE 90.1.
Imports the ASHRAE 90.1 constructions in the respective climate zone defined in Site, Location, and Weather section.
Opens the glazing database to import different glazing types. This database is a generic set of glazing types with chronological U-values, SHGC and Visual Transmittance.
Opens the Assign Constructions dialog, where imported constructions are assigned to the correct surfaces. All spaces in the model are selected by default.
To assign a construction to specific spaces or surfaces, work in the Apache module instead: select the spaces or surfaces, then select Assign Constructions in the toolbar.
Assigns a ground contact floor construction to the surfaces adjacent to the z = 0 elevation.
Skip this step if z = 0 is not ground level. In that case, assign the construction in Apache instead: select the surfaces, then select Assign Constructions in the toolbar.
Opens the Input Data Visualization with the settings preset to show a 3D view of the construction assignments. Use it to check that the correct constructions have been applied before running any calculations.
Imports thermal templates based on ASHRAE guidance into the project.
To review, edit or create thermal templates, open the Building Template Manager
Opens the Tabular Space Data dialog.
Select the drop-list in the Thermal Template column to assign a template to a space. Select multiple rooms first to assign the same template in bulk.
Opens the Input Data Visualization with the settings preset to show a 3D view of the thermal templates assigned. Use it to check that the correct thermal templates have been applied before running any calculations. For multiple stories it may be beneficial to select by Storey on the Exploded view input.
Opens the dialog for specifying the settings for a room and zone load calculation. Select Calculate to run it.
No system has been specified at this point, so the calculation must be repeated once a system is assigned in order to size it. Skip this step unless you need room and zone loads on their own.
Opens the Content Manager, the report viewer for reports generated within the VE.
If all the preceding steps have been completed, three reports are available: the climate assessment report, a PDF report giving results for each room and zone, and an .xlsx file holding the same load data in tabular form.
Offers one method to create a system. It opens the HVAC System Wizard to create a new or edit and existing system. Work through the steps of the wizard.
An alternative route to creating a system. Opens a new system along with the Import Prototype System dialog, from which the systems needed for the project are imported.
Tick the Stay in dialog box to import several systems in succession without the dialog closing after each one.
This step is available only once a system has been created.
It also serves as a reminder to assign each zone group to its system before continuing.
If a system file exists within the project, select the system file and open to edit and/or assign zone groups.
Opens the Design Preferences dialog. These preferences override performance data for the system sizing calculation only. The original data is retained for the energy simulation.
Typical items to consider include supply air temperature reset strategies and bypassing energy recovery wheels.
For a full account of the available overrides see HVAC Design Preferences.
Opens the Zone Airflow Distribution dialog for the most recent system edited. This dialog is used to review the airflow from the system to each zone and from each zone to each room. There are various ways to specify the airflow downstream of a zone terminal unit to each child room and two options are provided within IESVE Software. One procedure calculates the airflow of the child rooms at the time when the master (room with a thermostat) peaks and the other procedure calculations the airflow of the child rooms at the time when each unique child room peaks. This setting is also available in the global preferences.
Opens the dialog for running room and zone load calculations, system sizing calculations, iterative zone airflow and system equipment sizing, and simulation.
Select the calculations to run. For the goal of this Navigator, tick HVAC Zone/Room loads and sizing and HVAC System loads and sizing as a minimum, then select Run.
By the completion of the navigator you should have calculated heating and cooling loads for a created geometry and the HVAC system sizes required to maintain room temperature and humidity setpoints. More control may be offered by working through the individual modules so if you need or would like to get more detailed within the model, the next step is to work through the modules individually to get as detailed as you want.