Single-zone VAV heat pump in OpenStudio

edit

First, you're right that OpenStudio's OS:AirLoopHVAC:UnitarySystem is missing the control type option SingleZoneVAV which was added in E+ 8.7.0. I opened a github issue: #3280. Until it gets added to the OS App, a dead simple EnergyPlus measure could be used to switch the control point of each unitary system. Something like this:

worskpace.getObjectsByType("AirLoopHVAC:UnitarySystem".to_IddObjectType).each do |idf_unitary|
  idf_unitary.setString(1, "SingleZoneVAV")
end

Second, multispeed DX coils are wrapped in OpenStudio SDK, there just isn't any example in hvac_library.osm so you can't just drag one from the Library to your model in OS App.

But you can find several examples of demonstration of these objects using the Ruby API if you go to the OpenStudio-resources repository, in model/simulationtests. You want to look at these:

autosize_hvac.rb
multi_stage.rb
unitary_system_performance_multispeed.rb
unitary_system.rb

If you aren't that comfortable with the Ruby bindings to create all of your systems, you could just use the ruby bindings to modify your local hvac_library.osm and add one example of your system that you could then drag and drop in OS App. (I don't recommend doing this, but you could also just manually add all objects required for a unitary system with the inner components that you need in text mode, just mind that the 'handle' must be unique UUIDs)