There have been other posts about this extension but I figure I'll mention it again..but late. When Autodesk purchased Carmel Software (January 2008) they rebranded it and released it as a subscription benefit. Time for a pretty picture!
What it is:
The HVAC Load Calculation Extension by Autodesk, Inc. is a commercial and industrial HVAC (Heating, Ventilation, and Air Conditioning) load calculation software package whose calculations are based upon the ASHRAE 2005 Fundamentals radiant time series (RTS) method.
This tool will provide you with total cooling and heating loads for a building so that you may properly specify the correct size HVAC equipment (whether it is a packaged rooftop unit or a boiler). This program is geared specifically toward the HVAC engineer, architect, design/build mechanical contractor, and building maintenance supervisor.
Some key features:
Input HVAC system characteristics such as supply cooling and heating temperatures, ventilation rates, fan characteristics, cooling and heating setpoints, duct sizing, and safety factors
Input HVAC area (room) characteristics such as wall, window, roof, door, skylight, and partition areas. In addition, there are inputs for # of people, electrical appliances, infiltration, lighting, miscellaneous, exhaust, and plenum loads
Weather data from over 800 cities throughout the world
A complete u-value database for common wall, roof, window, floor, and door types
A complete appliance list for determining internal electrical equipment load contributions
Many reports including summary, detailed, psychrometric, wall/window breakdown, 24-hour load breakdown, and graphical reports
A feature that allows the user to export all inputs and outputs to custom Microsoft Word and Excel documents
Support for both English (IP) and Metric (SI) units
I've noticed a couple traces of Carmel still in the product the other day as pictured here.
The information provided here can be found in the Help documentation for this software. It is provided as a compliment to Revit and AutoCAD MEP software. Most notable is that you can export TO GBXML format from either product, then Import into this extension and THEN export BACK to them.
Check it out!