A reasonable consumption of control air for a thermostat is:

When assessing the consumption of control air for a thermostat, a typical range is recognized within the 30 - 40 scim range. This measurement refers to standard cubic inches per minute (scim) and is indicative of how much control air is required for optimal operation of a thermostat within a control system.

Thermostats often utilize control air to operate pneumatic control devices, and the 30 - 40 scim range generally reflects the necessary consumption for efficient functionality. This consumption range allows for adequate responsiveness in maintaining desired temperature settings while ensuring the system's integrity and performance.

Furthermore, using control air within this specified range helps avoid issues such as inadequate response time or energy inefficiency. Ensuring that the thermostat operates within the correct consumption parameters is crucial for the overall efficiency and effectiveness of the control system in which it is integrated. Other choices may suggest higher or lower air consumption, which may not align with typical operational requirements for thermostats in commercial building controls, leading to potential performance issues.