Detailed HVAC

This section describes the graphical interface provided by DesignBuilder for the assembly of component based HVAC systems which may be combined with building models for energy simulation using EnergyPlus.

Overview

HVAC system models in DesignBuilder are assembled by placing a number of pre-defined air and water distribution loops together with groups of zones which are then connected to form complete systems.

See the Detailed HVAC Overview Tutorial

The air and water loops incorporate a number of HVAC components connected together by pipes or ducts to form distribution systems. These loops can be modified to incorporate any additionally required components and then connected to associated components in other loops or to heating, cooling and ventilation equipment located in zones to form complete systems.

Zones are placed in the form of zone groups which enable a number of zones having the same HVAC equipment to be grouped together. Each zone in the group can different equipment ratings. The zone group mechanism greatly simplifies the HVAC schematic assembly in that only one set of equipment and connections needs to be defined for the group while maintaining the flexibility of changing equipment properties for individual zones within the group.

The pre-defined loops incorporate setpoint managers which enable the loop to run without any additional control. However, additional setpoint managers can be added to the various loops to customise the control of the system.

Data associated with all loops, zones and associated components can be edited via dialogs for specific system requirements.

After placing loops, zone groups and setpoint managers and completing the required loop connections to associated equipment, an EnergyPlus simulation can be conducted for the combined building and HVAC system model.

Accessing Detailed HVAC

To access detailed HVAC, you first need to select the Detailed HVAC option under the HVAC header on the Model Options dialog. After closing the Model Options dialog, a new <HVAC System> node will appear in the Navigator tree list:

Click on this <HVAC System> node to access the HVAC edit screen.

Detailed HVAC Contents

• Understanding HVAC Loops
• Air Loops
• Plant and Condenser Loops
• Understanding HVAC Zone Groups
• HVAC Component Hierarchy and Navigation
• HVAC System Control - Setpoint Managers
• Autosizing HVAC Components
• Working with Loops and Zone Groups (HVAC System Level)
• Working within Sub Loops (Sub Loop Level)
• Working within HVAC Zone Groups (HVAC Zone Group Level)
• Working within HVAC Zones (HVAC Zone Level)
• Working within Components (Component Level)
• HVAC Components

Detailed HVAC Terminology

The following points on HVAC terminology may help when referring to the documentation.

• The word "supply air" refers to the air being supplied to the zone. So for example the "supply air flow rate" is the rate of air delivered to the zone. It is not necessarily the fresh air delivery rate (though if there is no recirculation then it will be).