What you are describing can be done with Other Equipment described here in the input output reference.
I'm not aware of a measure that does this, but this measure that adds electric equipment to a space could be a good starting point. A few notes below.
- This measure is for electric equipment but could easily be switched to other equipment
- This measure assumes that the load definition and schedule exists and it just assigns them. This requires some work to be done in the seed model to add objects you may want to include. It could be extended to make the definition but would require more user arguments. Making a schedule on the fly isn't as easy unless it is very simple.