MEP Calculation, Sizing

Integrated system calculations 

The integrated system calculation allow designers to perform calculations throughout the design process in order to visualize planned system performance and to compare design alternatives if necessary. System calculation executes automatic sizing, and verification of compliance with design requirements.

1. Cross section automatic resizing

The cross-sections are resized based on the Equal Frictions Method.
Required input parameters:

• External static pressure: The total pressure loss of the system, you can specify it by selecting the Air Handling Unit (AHU) and editing the Pressure loss field on the Properties panel. This field is visible when the Category field is set to Mechanical equipment.
• Volumetric flow on each air terminal. This field is visible when the Category field is set to Air terminals.

Additional parameters:
• Pressure loss for the other mechanical equipment’s and air terminals. It is related to the specific object.
• Roughness of the ducts. You can specify it by selecting the duct, and editing the Roughness field manually, or by selecting a material in the Piping material (roughness) field.
• Constraints can be specified for the ducts' height and width, this can be set in the Sizing method field.
• The system's environmental temperature. You can specify it by selecting one of the ducts, clicking the MEP->System->Properties button and editing the corresponding fields in the dialog window.

The calculation will run only if there is one AHU in the system and an air terminal on each end with the required parameters specified.

The calculation of the Darcy-Weisbach friction factor is based on the Swamee-Jain equation. An equivalent diameter is calculated for the non-circular ducts. The program calculates the following physical parameters for each duct:
• Volumetric flow
• Velocity
• Friction
• Pressure drop
• Velocity pressure
• Reynolds number

2. Changing the size manually

The software, thanks to the System concept, is able to break down the network of connected pipes or ducts into Sections and Branches.
Branch: set of sections, between one branch and another.
Section: Single piece of pipe or duct between two nodes.

It is possible to modify the section of a section or of an entire branch. The software will take care of keeping the circuit connected, adding the reductions, or modifying the properties of the fittings..

Edit entire branch

Edit single part