Final answer:
Pressure control systems are used to cycle compressors on and off in response to evaporator pressures, which manage the temperature within a space by regulating the refrigeration or heat pump cycle.
Step-by-step explanation:
The type of control used to cycle compressors on and off in response to evaporator pressures, which indirectly control box temperature, is typically a pressure control system. This system works as part of a refrigeration or heat pump cycle to maintain desired temperatures by regulating the operation of compressors based on the pressure of refrigerants within the evaporator coils.
During the cycle, an electrically driven compressor inputs work (W), raising the temperature and pressure of the refrigerant gas and pushing it into the condenser coils. Here, since the gas is hotter than the indoor air, heat is transferred to the room, causing the gas to condense into a liquid. This liquid then goes through an expansion valve, cooling it through expansion, and is sent to the evaporator coils outside.
In heating mode, this process reverses: heat is taken from the outside air and transferred inside as the refrigerant changes state. The pressure control system ensures that the compressor activates or deactivates to keep up with the heating or cooling demand, sustaining the right temperature in the conditioned space.