A wide range of autosizable system templates can be loaded pre-connected and all systems can be customised either at the placement stage or afterwards following placement. Pre-defined HVAC templates, autosizing and zone grouping features save significant input time compared to competing products. However HVAC systems can be defined manually from scratch if required for more bespoke system types.

The most commonly used EnergyPlus HVAC system types are all available in DesignBuilder. Both air and water sides are treated together in full detail with a good range of components, including all ASHRAE 90.1 baseline HVAC systems. 

Technical specifications

  • In EnergyPlus the HVAC and building 3D models are simulated simultaneously to ensure the dynamic interaction between the building and systems is treated accurately.
  • Graphical definition of hot and chilled water supply, condenser and air loops through placement of components, mixers and splitters.
  • Select from a range of fully connected HVAC templates or define bespoke systems manually.
  • Extensible library of E+ components, including boilers, chillers, heating coils, heat pumps, cooling coils, pumps, fans, humidifiers, set-point managers, etc.
  • Templates for component data, e.g.boilers, chillers and performance curves etc.
  • ASHRAE 90.1 baseline HVAC system types #1 - #13 are all included.
  • Zone groups allow multiple zones having similar system types to be grouped together simplifying the HVAC diagram layout and speeding data entry.
  • Graphical representation of zones featuring drag and drop facilities for ADUs (air distribution units), radiant heating/cooling devices, fan coil units, etc.
  • Full set of EnergyPlus HVAC outputs can be generated including system node temperatures, flow rates and humidity levels at sub-hourly intervals.
  • Comprehensive set of zone air distribution (terminal) units including cooled beams, direct air, dual duct CAV, dual duct VAV, single duct CAV reheat, single duct VAV. with/without reheat, single duct VAV reheat with variable speed fan, series PIU (VAV terminal type), parallel PIU, four pipe induction.
  • Chilled ceilings and heated floors can be combined with other system types. Radiant systems are modelled in detail using water pipes buried in surface layers.
  • Multiple air handling units with drag and drop facilities for including fans, heating and cooling coils, humidifiers, etc.
  • Multiple boilers and chillers in plant loops with plant operation scheme management options based on load and schedules.
  • Zone forced air units including fan coil units, packaged heat pumps and packaged air conditioner can be used in zones together with air from AHUs.
  • Automatic network integrity and connection compatibility checks.
  • Import/export ability to create & save own custom systems to library.
  • EnergyPlus provides an encyclopaedic range of system types and all of these can accessed by exporting a DesignBuilder model to EnergyPlus.
  • For more specialised systems and controls, the EMS runtime scripting tools can be used to extend HVAC to simulate unlimited variations on the standard systems.
  • Heat exchangers allow heat to be passed from one loop to another allowing a wide range of standard and more innovate system types to be modelled.

Some examples of HVAC system types included in DesignBuilder:

  • VAV systems with state-of-the-art controls, air and water supply temperature resets, air side economizer/free cooling, CO2-based demand-controlled ventilation (DCV).
  • VRF systems with air or water cooling including a range of built-in manufacturers data.
  • Mixed-mode systems with integrated control of mechanical and natural ventilation
  • Dedicated outside air systems (DOAS) can be included with all zone-based systems such as fan coils units, active/passive chilled beams, hot water radiators etc.
  • Unitary cooling (split systems).
  • Radiant systems with heating/cooled floors, ceilings, panels etc.
  • Range of evaporative cooling systems.
  • Hybrid hydronic/air systems.
  • Underfloor air distribution (UFAD) and displacement ventilation (DV) including sophisticated zone air temperature distribution with a range of options for modelling separate occupied and stratified zones, plumes and fixed/variable volume diffusers.
  • Vented stack-effect double-skin facades
  • Comprehensive Ground Source Heat Pump (GSHP) modelling, including vertical borehole, surface and pond heat exchangers. Links are provided to GLD and GLHEPRO for importing detailed ground heat exchanger data.
  • Solar hot water collectors with dedicated storage, providing heat to DHW and/or space heating (e.g. heated floor).
  • Hollow-core slab systems.
  • Cogeneration and trigeneration systems.
  • Ice thermal storage systems.


HVAC is included in all the Engineering packages. It can also be purchased as a separate module.


The HVAC module also requires the Simulation module.

“DesignBuilder’s clear, well-structured layout and intuitive help system makes it a much simpler tool to learn and use, and compared to other simulation packages the creation of professional-looking geometry is much easier. The ease of use extends to other areas of the program such as thermal bridging analysis and setting up HVAC systems, and the capability to easily model adjacent ground conditions is very useful. A very important aspect of our work is optimisation, and DesignBuilder seems to be the only software that currently provides this functionality. We are encouraged that the development team have taken some of our functionality and user efficiency suggestions on board for the next release. We are already using DesignBuilder for research, and for the above reasons we think it is a tool that our students will find easier to use so we will be using it for teaching next academic year.”
Professor Ljubomir Jankovic, Birmingham School of Architecture
Birmingham City University, UK

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