by LITIO Sheet metal for AutoCAD. It calculates flat (unfolded) sheet development of ducts, rectangle to ound transitions, cylinders, cones, intersections, connections, bifurcations, elbows, etc. For HVAC, hoppers, cyclones, ducts, silos, piping, etc.
by Baltik Engineering ComfortAir HVAC software is designed to be used by engineers, architects, contractors and energy auditors for calculating and analysing heating and air conditioning hourly loads in all types of buildings. Units can be set to English or Metric.
by ArchiTech Software The easiest way calculate residential and light commercial heating and cooling hvac loads by the Manual J method. You can toggle an option to get real time results like a spreadsheet - it's great for fine tuning a design for best energy efficiency.