Why do you need a specific resource for the comparison of those two systems?
If you know what both VAV and FCs are about and what they involve to make them into a complete system then you can figure out the comparison for yourself.
Or is there anything in specific you are looking for?
On the energy side, FC systems will beat VAV systems nearly every time. From the maintenance side, FC have a lot of filters, motors and belts to look after.
