Added a zone-based optimization.

code/controllers/subsystem/adjacent_air.dm

@@ -4,6 +4,7 @@ SUBSYSTEM_DEF(adjacent_air)
 	runlevels = RUNLEVEL_GAME | RUNLEVEL_POSTGAME
 	wait = 10
 	priority = FIRE_PRIORITY_ATMOS_ADJACENCY
+	init_order = INIT_ORDER_AIR_TURFS
 	var/list/queue = list()
 
 /datum/controller/subsystem/adjacent_air/stat_entry(msg)
@@ -17,8 +18,11 @@ SUBSYSTEM_DEF(adjacent_air)
 /datum/controller/subsystem/adjacent_air/Initialize()
 	while(length(queue))
 		fire(mc_check = FALSE)
+	build_zones()
 	return ..()
 
+/datum/controller/subsystem/adjacent_air/proc/build_zones()
+
 /datum/controller/subsystem/adjacent_air/fire(resumed = FALSE, mc_check = TRUE)
 
 	var/list/queue = src.queue