Are there sterile transfer areas in Juan Santamaria airport?

I am traveling from Madrid to San Salvador via Costa Rica's Juan Santamaria Airport. The flights with proper transfers are rather expensive so I am booking a self transfer and I am trying to get an idea of the time I should allow myself. There are options from 1h to 7h, obviously I would like to cut down on the layover time so my question is:

Will I need to go through passport control or are there sterile transfer areas?

I tried to look this up but couldn't find info. Anyone's experience would be helpful. Cheers