Tery, not the evaporator, maybe the receiver dryer or accumulator.
The evaporator is buried under the dash, it's big time job replacing that. And I know from personal experience on it.
The receiver dryer or accumulator, two names for the same item, sits on the firewall.
It's an easy item to replace, and yes it's job is to contain any moisture in the freon system. Replacing it, and the orifice are mandatory anytime the system is opened up.
Most likely the freon has dropped enough it won't allow the compressor to kick on.
It would be wise to have it recharged, and leak tested. And hopefully you don't end up like me with this week's project. Replacing the evap, dryer, orifice, after removing the dash. And yep it's getting a new heater core too. No way do I want to do that job twice.