Hot water control setpoint based on outside air temperature

A Reset math object establishes a hot water control setpoint based on the outside air temperature at InA.

The Reset component is located in the Math folder of the kitControl palette.

Figure 1. Reset properties


When the outside air temperature is 0° F, the hot water setpoint is 200° F. When the outside air temperature is 75° F, the hot water setpoint is 100° F. The Reset object is configured as:

  • Input Low Limit = 0.0

  • Input High Limit = 75.0

  • Output Low Limit = 200.0

  • Output High Limit = 100.0

If the InA value is beyond the input limits, the output is limited by the corresponding output limit (in this case, 200 at 0° F or below, 100 at 75° F or above). When the input is at an intermediate value, the output scales linearly. For example, when the outside air temperature is at 38.2° F, the Reset output is 149.1° F.