GBS - HVAC options restrictive

[Shaun v Rooyen]

Is there a plug-in for more options to HVAC choices in Design Options?. The list of 5-6 is very restrictive.

If this is a true green system why is there not a HVAC option like a "2 Stage Evaporative System?
Evaporative cooling is a very common form of cooling buildings for thermal comfort since it is relatively cheap and requires less energy than many other forms of cooling.

Is there a way to add more options to the HVAC list in either GBS or Revit MEP?

thx

[marjorie.stein]

We are in the process of updating the choices for HVAC systems. But the biggest thing to keep in mind is that GBS is meant for early schematic design decisions. We intend this tool to be used for designers to optimize their building footprint, orientation, and opening locations/sizes for minimal energy usage BEFORE anyone even begins to consider what type of HVAC system to included. How well can you optimize the project for taking advantage of natural ventilation and natural daylighting before you address the problem of needing an HVAC system?
Once you have the building form optimized, then you can export your model from GBS into more detailed engineering tools, such as EnergyPlus or eQUEST where you can fine-tune the HVAC system details.

[Mike Sealander]

It may also help to remember that energy modeling of buildings is based around ASHRAE 90.1 appendix G, and GBS appears to be very helpful in modeling base-case designs. For GBS to approach the level of modeling minutiae that eQuest can do, it would end up being a very involved program. We've been using the Revit>GBS>eQuest workflow for looking at purely architectural issues (fenestration, opaque wall, orientation, lighting, schedules), and find the process is...not bad.