Items not spawing CAF related

**im bit new to g mod 13
i am not able to spawn item like heat exchanger or air exchanger from the enviroinment stuff in CAF. I can see it but not able to spawn it, and i have all the required stuff for it.

The only things i can spawn is suit dispenser and climate probe or something.**

i saw somewhere about using gamemode and i dont really understand how.

if someone could help me it would be greatly appreciated.