Messana’s 0-10V fan speed modulation system dynamically adjusts the speed of hydronic fan coils based on the difference between the setpoint (desired temperature) and the current room temperature. The user can set a modulation differential temperature (Modulation differential, default value 6°F), with the system starting to modulate when this differential is met or exceeded. The fan operates at the maximum speed set by the user (Max speed, default 100%) when the temperature differential is more than the modulation differential temperature. As the temperature gets closer to the setpoint, the system begins to modulate, reducing the fan speed proportionately down to a minimum speed set by the user (Min speed, default 20%). Once the setpoint is reached, the fan coil operation is stopped. This dynamic adjustment of fan speed optimizes comfort and energy efficiency by reducing noise and unnecessary system cycling.
Example
Suppose the setpoint is 75°F, the user has set the maximum fan speed to 80% of the total capacity, the minimum speed to 10%, and the modulation differential temperature to 5°F. If the current room temperature is 80°F or higher (a 5°F or more differential), the Messana system runs the hydronic fan coil at the maximum set speed (equivalent to an 8V signal) to cool down the room.
When the room temperature drops below 80°F but still more than the setpoint, the system begins to modulate, progressively reducing the fan speed by lowering the control signal. This modulation continues as the room temperature moves closer to the setpoint, with the speed never going below the minimum speed set by the user.