Racking ZMACS + PS2A - optimal order for heat dissipation

I’m racking my new ZMACs 4X4 and PS-2A in a 4U Gator rack case:

  • 1U for the ZMACS
  • 2U for the PS-2A
  • 1U for a vantilated blanking panel

Is there an optimal placement order to allow the best airflow for the PS-2A fans?

The rack will be homed (mostly) in an air conditioned studio environment and open at the front and back so I’m not too worried about overheating, but want to give it the ideal environment (if there is such a thing).

Many thanks in advance.