Humidifier control systems and methods

1. A humidifier control system for a building, comprising:

a humidity load module configured to:

obtain an outdoor ambient temperature at the building and an outdoor relative humidity (RH) at the building; and,

at a first time, determine a predicted humidity load of a future predetermined period based on a temperature of air within the building, a RH of air within the building, the outdoor ambient temperature, the outdoor RH, a predetermined air exchange rate of the building with outdoors, and an interior volume of the building,

wherein the future predetermined period is after the first time;

a humidification module configured to determine a predicted humidification provided by a humidifier within the building during the future predetermined period based on:

a period that the humidifier was on during a previous predetermined period, wherein the previous predetermined period is before the future predetermined period; and

a predetermined evaporation rate of the humidifier when the humidifier is on; and

a humidifier control module configured to open a water feed valve of the humidifier in response to a determination that the predicted humidification for the future predetermined period is less than the predicted humidity load of the future predetermined period.

2. The humidifier control system of claim 1 wherein the humidifier control module is configured to open the water feed valve of the humidifier before the future predetermined period in response to the determination that the predicted humidification for the future predetermined period is less than the predicted humidity load of the future predetermined period.

3. The humidifier control system of claim 2 wherein, in response to the determination that the predicted humidification for the future predetermined period is less than the predicted humidity load of the future predetermined period, the humidifier control module is configured to open the water feed valve of the humidifier before the future predetermined period when the RH of air within the building is greater than a predetermined humidification setpoint.

4. The humidifier control system of claim 1 wherein the humidifier control module is configured to open the water feed valve of the humidifier during the future predetermined period in response to the determination that the predicted humidification for the future predetermined period is less than the predicted humidity load of the future predetermined period.

5. The humidifier control system of claim 4 wherein, in response to the determination that the predicted humidification for the future predetermined period is less than the predicted humidity load of the future predetermined period, the humidifier control module is configured to open the water feed valve of the humidifier during the future predetermined period when the RH of air within the building is greater than a predetermined humidification setpoint.

6. The humidifier control system of claim 1 further comprising an indoor air quality (IAQ) module of the building and that comprises:

a temperature sensor configured to measure the temperature of air within the building; and

a RH sensor configured to measure the RH of air within the building.

7. The humidifier control system of claim 1 wherein the humidity load module is configured to:

receive predicted outdoor temperatures at predetermined times during the future predetermined period;

determine the outdoor ambient temperature at the building based on an average of the predicted outdoor temperatures at the predetermined times;

receive predicted outdoor RHs at the predetermined times during the future predetermined period; and

determine the outdoor ambient RH at the building based on an average of the predicted outdoor RHs at the predetermined times.

8. The humidifier control system of claim 1 wherein the humidity load module is configured to:

receive a first predicted outdoor ambient temperature at a first predetermined time during the future predetermined period;

receive a second predicted outdoor ambient temperature at a second predetermined time during the future predetermined period;

receive a first predicted outdoor RH at the first predetermined time during the future predetermined period;

receive a second predicted outdoor RH at the second predetermined time during the future predetermined period;

determine a first predicted humidity load based on the temperature of air within the building, the RH of air within the building, the first predicted outdoor ambient temperature, the first predicted outdoor RH, the predetermined air exchange rate of the building with outdoors, and the interior volume of the building;

determine a second predicted humidity load based on the temperature of air within the building, the RH of air within the building, the second predicted outdoor ambient temperature, the second predicted outdoor RH, the predetermined air exchange rate of the building with outdoors, and the interior volume of the building; and

set the predicted humidity load based on the first predicted humidity load plus the second predicted humidity load.

9. The humidifier control system of claim 1 wherein the temperature of air within the building is a setpoint temperature within the building.

10. The humidifier control system of claim 1 wherein the RH of air within the building is a setpoint RH within the building.

11. The humidifier control system of claim 1 wherein the temperature of air within the building is an average air temperature within the building over the previous predetermined period.

12. The humidifier control system of claim 1 wherein the RH of air within the building is an average RH of air within the building over the previous predetermined period.

13. A humidifier control method, comprising:

obtaining an outdoor ambient temperature at a building;

obtaining an outdoor relative humidity (RH) at the building;

at a first time, determining a predicted humidity load of a future predetermined period based on a temperature of air within the building, a RH of air within the building, the outdoor ambient temperature, the outdoor RH, a predetermined air exchange rate of the building with outdoors, and an interior volume of the building,

wherein the future predetermined period is after the first time;

determining a predicted humidification provided by a humidifier within the building during the future predetermined period based on:

a period that the humidifier was on during a previous predetermined period, wherein the previous predetermined period is before the future predetermined period; and

a predetermined evaporation rate of the humidifier when the humidifier is on; and

opening a water feed valve of the humidifier in response to a determination that the predicted humidification for the future predetermined period is less than the predicted humidity load of the future predetermined period.

14. The humidifier control method of claim 13 wherein opening the water feed valve includes opening the water feed valve of the humidifier before the future predetermined period in response to the determination that the predicted humidification for the future predetermined period is less than the predicted humidity load of the future predetermined period.

15. The humidifier control method of claim 14 wherein opening the water feed valve includes, in response to the determination that the predicted humidification for the future predetermined period is less than the predicted humidity load of the future predetermined period, opening the water feed valve of the humidifier before the future predetermined period when the RH of air within the building is greater than a predetermined humidification setpoint.

16. The humidifier control method of claim 13 wherein opening the water feed valve includes opening the water feed valve of the humidifier during the future predetermined period in response to the determination that the predicted humidification for the future predetermined period is less than the predicted humidity load of the future predetermined period.

17. The humidifier control method of claim 16 wherein opening the water feed valve includes, in response to the determination that the predicted humidification for the future predetermined period is less than the predicted humidity load of the future predetermined period, opening the water feed valve of the humidifier during the future predetermined period when the RH of air within the building is greater than a predetermined humidification setpoint.

18. The humidifier control method of claim 13 further comprising:

by a temperature sensor of an indoor air quality (IAQ) sensor module of the building, measuring the temperature of air within the building; and

by a RH sensor of the IAQ sensor module, measuring the RH of air within the building.

19. The humidifier control method of claim 13 further comprising:

receiving predicted outdoor temperatures at predetermined times during the future predetermined period;

determining the outdoor ambient temperature at the building based on an average of the predicted outdoor temperatures at the predetermined times;

receiving predicted outdoor RHs at the predetermined times during the future predetermined period; and

determining the outdoor ambient RH at the building based on an average of the predicted outdoor RHs at the predetermined times.

20. The humidifier control method of claim 13 further comprising:

receiving a first predicted outdoor ambient temperature at a first predetermined time during the future predetermined period;

receiving a second predicted outdoor ambient temperature at a second predetermined time during the future predetermined period;

receiving a first predicted outdoor RH at the first predetermined time during the future predetermined period;

receiving a second predicted outdoor RH at the second predetermined time during the future predetermined period;

determining a first predicted humidity load based on the temperature of air within the building, the RH of air within the building, the first predicted outdoor ambient temperature, the first predicted outdoor RH, the predetermined air exchange rate of the building with outdoors, and the interior volume of the building;

determining a second predicted humidity load based on the temperature of air within the building, the RH of air within the building, the second predicted outdoor ambient temperature, the second predicted outdoor RH, the predetermined air exchange rate of the building with outdoors, and the interior volume of the building; and

setting the predicted humidity load based on the first predicted humidity load plus the second predicted humidity load.

21. The humidifier control method of claim 13 wherein the temperature of air within the building is a setpoint temperature within the building.

22. The humidifier control method of claim 13 wherein the RH of air within the building is a setpoint RH within the building.

23. The humidifier control method of claim 13 wherein the temperature of air within the building is an average air temperature within the building over the previous predetermined period.

24. The humidifier control method of claim 13 wherein the RH of air within the building is an average RH of air within the building over the previous predetermined period.

25. A humidifier control method, comprising:

obtaining an outdoor ambient temperature at a building;

obtaining an outdoor relative humidity (RH) at the building;

determining a humidity load based on a temperature of air within the building, a RH of air within the building, the outdoor ambient temperature, the outdoor RH, a volume of the building, a predetermined air exchange rate of the building with outdoors, and an interior volume of the building;

determining a humidification provided by a humidifier within the building based on:

a period that the humidifier was on during a previous predetermined period; and

a predetermined evaporation rate of the humidifier when the humidifier is on; and

opening a water feed valve of the humidifier in response to a determination that the humidification is less than the humidity load.