Temperature in the room ...

Temperature in the room should be limited to the control panel supplier's requirements.

Electonic components like PLC and HMI for instance require controllable limits to avoid overheating and malfunctioning.

Also dosing tanks may need moderate low temperatures (e.g. Chlorinating Chemicals).

Membranes will only be affected by feedwater temperature which should be taken into consideration by your RO supplier during the design of your equipment. Room temperature is not of any relevance in this regard.