Routerboard of cAP AC in outdoor case?

Hello,

I need some outdoor access point running in CAPSMAN forwarding mode. Therefore I need more CPU throughput, more than a normal wAP ac offers. Therefore I am asking myself whether it is possible to put a routerboard of cAP ac into some outdoor case (of wAP ac or something else) Is a cAP routerboard meant to work in outdoor environment at all?
Should I use a RBM33G instead? What do you use for outdoor installation currently?

Regards