Although maintaining temperature in mechanical and electrical rooms is not as critical as a server room, maintaining humidity is important for keeping equipment in good working order. Typical modern split AC systems use HCFC gases, such as R407C, R410A.
Should there be a failure of any part of the system, there is a risk of refrigerant gas leaking into the atmosphere. Leaking systems are inefficient and more expensive to operate but also pose a health risk to occupants as refrigerant gas depletes oxygen and can in some cases cause suffocation.