Patent Publication Number: US-10767878-B2

Title: Humidifier control systems and methods

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/589,035, filed on Nov. 21, 2017, U.S. Provisional Application No. 62/589,041, filed on Nov. 21, 2017, U.S. Provisional Application No. 62/589,046, filed on Nov. 21, 2017, U.S. Provisional Application No. 62/589,049, filed on Nov. 21, 2017, U.S. Provisional Application No. 62/660,361, filed on Apr. 20, 2018, and U.S. Provisional Application No. 62/660,393, filed on Apr. 20, 2018. The entire disclosures of the applications referenced above are incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure relates to environmental control systems and more particularly to systems and methods for controlling indoor humidity. 
     BACKGROUND 
     The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. 
     A residential or light commercial HVAC (heating, ventilation, and/or air conditioning) system controls temperature and humidity of a building. Upper and lower temperature limits may be specified by an occupant or owner of the building, such as an employee working in the building or a homeowner. 
     A thermostat controls operation of the HVAC system based on a comparison of the temperature at a thermostat and the target values. The thermostat may control the HVAC system to heat the building when the temperature is less than the lower temperature limit. The thermostat may control the HVAC system to cool the building when the temperature is greater than the upper temperature limit. Heating the building and cooling the building generally decreases humidity, although the HVAC system may include a humidifier that adds humidity to warm air output by the HVAC system during heating of the building. 
     SUMMARY 
     In a feature, an indoor air quality (IAQ) system for a building is described. A temperature sensor is configured to measure a temperature of air within the building. A relative humidity (RH) sensor is configured to measure a RH of the air within the building. At least one of a thermostat and an IAQ control module is configured to, during cooling of the air within the building, based on the RH, control operation of: a blower of an air handler unit of a heating, ventilation, and air conditioning (HVAC) system of the building; and a compressor of a condenser unit of the HVAC system of the building. The at least one of the thermostat and the IAQ control module is configured to, while the compressor is off: operate the blower at a first predetermined speed when the RH is less than a first predetermined RH but greater than a second predetermined RH; and operate the blower at a second predetermined speed that is greater than the first predetermined speed when the RH is less than the second predetermined RH. 
     In further features, the one of the thermostat and the IAQ control module is configured to, during cooling of the air within the building: selectively turn the compressor on and off based on the RH; and selectively turn the blower on and off based on the RH. 
     In further features, the one of the thermostat and the IAQ control module is configured to, in response to a determination that the RH is greater than a third predetermined RH: operate the blower; and operate the compressor. 
     In further features, the one of the thermostat and the IAQ control module is configured to, in response to a determination that the RH is less than a fourth predetermined RH that is less than the third predetermined RH: operate the blower; and disable the compressor. 
     In further features, the one of the thermostat and the IAQ control module is configured to, in response to a determination that the RH is greater than a third predetermined RH: operate the blower at a third predetermined speed; and operate the compressor. 
     In further features, the one of the thermostat and the IAQ control module is configured to, in response to a determination that the RH is greater than a fourth predetermined RH that is greater than the third predetermined RH: operate the blower at a fourth predetermined speed that is less than the third predetermined speed; and operate the compressor. 
     In further features, the one of the thermostat and the IAQ control module is configured to, in response to determinations that the RH is not greater than the third predetermined RH and is not less than the first predetermined RH: operate the blower at the third predetermined speed that is greater than the fourth predetermined speed; and operate the compressor. 
     In further features, the one of the thermostat and the IAQ control module is configured to, in response to a determination that the RH is less than a third predetermined RH: operate the blower at a third predetermined speed; and disable the compressor. 
     In further features, the one of the thermostat and the IAQ control module is configured to, in response to a determination that the RH is less than a fourth predetermined RH that is less than the third predetermined RH: operate the blower at a fourth predetermined speed that is greater than the third predetermined speed; and disable the compressor. 
     In a feature, an indoor air quality (IAQ) control method for a building, includes: by a temperature sensor, measuring a temperature of air within the building; by a relative humidity (RH) sensor, measuring a RH of the air within the building; and by at least one of a thermostat and an IAQ control module, during cooling of the air within the building, based on the RH, controlling operation of: a blower of an air handler unit of a heating, ventilation, and air conditioning (HVAC) system of the building; and a compressor of a condenser unit of the HVAC system of the building, where the control includes, while the compressor is off: operating the blower at a first predetermined speed when the RH is less than a first predetermined RH but greater than a second predetermined RH; and operating the blower at a second predetermined speed that is greater than the first predetermined speed when the RH is less than the second predetermined RH. 
     In further features, the controlling operation includes, by the at least one of the thermostat and the IAQ control module, during cooling of the air within the building, based on the RH: selectively turning the compressor on and off based on the RH; and selectively turning the blower on and off based on the RH. 
     In further features, the controlling operation includes, by the at least one of the thermostat and the IAQ control module, in response to a determination that the RH is greater than a third predetermined RH: operating the blower; and operating the compressor. 
     In further features, the controlling operation includes, by the at least one of the thermostat and the IAQ control module, during cooling of the air within the building, in response to a determination that the RH is less than a fourth predetermined RH that is less than the third predetermined RH: operating the blower; and disabling the compressor. 
     In further features, the controlling operation includes, by the at least one of the thermostat and the IAQ control module, during cooling of the air within the building, in response to a determination that the RH is greater than a third predetermined RH: operating the blower at a third predetermined speed; and operating the compressor. 
     In further features, the controlling operation includes, by the at least one of the thermostat and the IAQ control module, during cooling of the air within the building, in response to a determination that the RH is greater than a fourth predetermined RH that is greater than the third predetermined RH: operating the blower at a fourth predetermined speed that is less than the third predetermined speed; and operating the compressor. 
     In further features, the controlling operation includes, by the at least one of the thermostat and the IAQ control module, during cooling of the air within the building, in response to determinations that the RH is not greater than the third predetermined RH and is not less than the first predetermined RH: operating the blower at the third predetermined speed that is greater than the fourth predetermined speed; and operating the compressor. 
     In further features, the controlling operation includes, by the at least one of the thermostat and the IAQ control module, during cooling of the air within the building, in response to a determination that the RH is less than a third predetermined RH: operating the blower at a third predetermined speed; and disabling the compressor. 
     In further features, the controlling operation includes, by the at least one of the thermostat and the IAQ control module, during cooling of the air within the building, in response to a determination that the RH is less than a fourth predetermined RH that is less than the third predetermined RH: operating the blower at a fourth predetermined speed that is greater than the third predetermined speed; and disabling the compressor. 
     In a feature, a humidifier control system for a building is described. An IAQ sensor module is located within the building and includes: a particulate sensor configured to measure an amount of particulate of at least a predetermined size present in air at the IAQ sensor module; a volatile organic compound (VOC) sensor configured to measure an amount of VOCs present in air at the IAQ sensor module; and an average module configured to determine an average relative humidity (RH) of air within the building. An IAQ score module is configured to determine an IAQ score value for air within the building based on the amount of particulate, the amount of VOCs, a RH of air within the building, and a temperature of air within the building. A humidifier control module is configured to selectively open and close a water feed valve of a humidifier within the building based on the IAQ score value and the average RH. 
     In further features, the humidifier control module is configured to open the water feed valve of the humidifier in response to a determination that the average RH is less than a predetermined RH while a blower that blows air through the humidifier is on. 
     In further features, the humidifier control module is configured to maintain the water feed valve of the humidifier open until an increase in the IAQ score value over a period is less than or equal to zero. 
     In further features, the humidifier control module is configured to close the water feed valve of the humidifier in response to a determination that the increase in the IAQ score value over a period is less than or equal to zero. 
     In further features, the humidifier control module is configured to close the water feed valve of the humidifier in response to a determination that a temperature of air output by an air handler unit to the building is less than a predetermined temperature. 
     In further features, a setpoint module is configured to adjust the predetermined RH in response to receipt of user input. 
     In further features, the humidifier control module is further configured to turn on a humidifier blower when the water feed valve is open. 
     In further features, the humidifier control module is configured to close the water feed valve of the humidifier in response to a determination that a temperature of air output by an air handler unit to the building is less than a predetermined temperature. 
     In further features, the IAQ sensor module further includes: a temperature sensor configured to measure the temperature of air; and a RH sensor configured to measure the RH of air. 
     In further features, the IAQ sensor module further includes a carbon dioxide sensor configured to measure an amount of carbon dioxide present in air at the IAQ sensor module. The IAQ score module is configured to determine the IAQ score value for the air further based on the amount of carbon dioxide. 
     In further features, at least one of: the IAQ score module is configured to decrease the IAQ score value when the amount of particulate is greater than a predetermined amount of particulate; the IAQ score module is configured to decrease the IAQ score value when the amount of VOCs is greater than a predetermined amount of VOCs; the IAQ score module is configured to decrease the IAQ score value when the amount of carbon dioxide is greater than a predetermined amount of carbon dioxide; the IAQ score module is configured to decrease the IAQ score value when the RH is outside of a predetermined RH range; and the IAQ score module is configured to decrease the IAQ score value when the temperature is outside of a predetermined temperature range. 
     In further features, all of: the IAQ score module is configured to decrease the IAQ score value when the amount of particulate is greater than a predetermined amount of particulate; the IAQ score module is configured to decrease the IAQ score value when the amount of VOCs is greater than a predetermined amount of VOCs; the IAQ score module is configured to decrease the IAQ score value when the amount of carbon dioxide is greater than a predetermined amount of carbon dioxide; the IAQ score module is configured to decrease the IAQ score value when the RH is outside of a predetermined RH range; and the IAQ score module is configured to decrease the IAQ score value when the temperature is outside of a predetermined temperature range. 
     In further features, at least one of: the IAQ score module is configured to decrease the IAQ score value as a first period that the amount of particulate has been greater than a predetermined amount of particulate increases; the IAQ score module is configured to decrease the IAQ score value as a second period that the amount of VOCs has been greater than a predetermined amount of VOCs increases; the IAQ score module is configured to decrease the IAQ score value as a third period that the amount of carbon dioxide has been greater than a predetermined amount of carbon dioxide increases; the IAQ score module is configured to decrease the IAQ score value as a fourth period that the RH has been outside of a predetermined RH range increases; and the IAQ score module is configured to decrease the IAQ score value as a fifth period that the temperature has been outside of a predetermined temperature range increases. 
     In a feature, a humidifier control method includes: by a particulate sensor of an indoor air quality (IAQ) sensor module within a building, measuring an amount of particulate of at least a predetermined size present in air at the IAQ sensor module; by a volatile organic compound (VOC) sensor of the IAQ sensor module within the building, measuring an amount of VOCs present in air at the IAQ sensor module; and determining an average relative humidity (RH) of air within the building; determining an IAQ score value for air within the building based on the amount of particulate, the amount of VOCs, a RH of air within the building, and a temperature of air within the building; and selectively opening and closing a water feed valve of a humidifier within the building based on the IAQ score value and the average RH. 
     In further features, selectively opening and closing a water feed valve includes opening the water feed valve of the humidifier in response to a determination that the average RH is less than a predetermined RH while a blower that blows air through the humidifier is on. 
     In further features, selectively opening and closing a water feed valve includes maintaining the water feed valve of the humidifier open until an increase in the IAQ score value over a period is less than or equal to zero. 
     In further features, selectively opening and closing a water feed valve includes closing the water feed valve of the humidifier in response to a determination that the increase in the IAQ score value over a period is less than or equal to zero. 
     In further features, selectively opening and closing a water feed valve includes closing the water feed valve of the humidifier in response to a determination that a temperature of air output by an air handler unit to the building is less than a predetermined temperature. 
     In further features, the humidifier control method further includes adjusting the predetermined RH in response to receipt of user input. 
     In further features, the humidifier control method further includes turning on a humidifier blower when the water feed valve is open. 
     In further features, selectively opening and closing a water feed valve includes closing the water feed valve of the humidifier in response to a determination that a temperature of air output by an air handler unit to the building is less than a predetermined temperature. 
     In further features, the humidifier control method further includes: by a temperature sensor of the IAQ sensor module, measuring the temperature of air; and by a RH sensor of the IAQ sensor module, measuring the RH of air. 
     In further features, the humidifier control method further includes, by a carbon dioxide sensor of the IAQ sensor module within the building, measuring an amount of carbon dioxide present in air at the IAQ sensor module, where determining the IAQ score value includes determining the IAQ score value for the air further based on the amount of carbon dioxide. 
     In further features, determining an IAQ score value includes at least one of: decreasing the IAQ score value when the amount of particulate is greater than a predetermined amount of particulate; decreasing the IAQ score value when the amount of VOCs is greater than a predetermined amount of VOCs; decreasing the IAQ score value when the amount of carbon dioxide is greater than a predetermined amount of carbon dioxide; decreasing the IAQ score value when the RH is outside of a predetermined RH range; and decreasing the IAQ score value when the temperature is outside of a predetermined temperature range. 
     In further features, determining an IAQ score value includes all of: decreasing the IAQ score value when the amount of particulate is greater than a predetermined amount of particulate; decreasing the IAQ score value when the amount of VOCs is greater than a predetermined amount of VOCs; decreasing the IAQ score value when the amount of carbon dioxide is greater than a predetermined amount of carbon dioxide; decreasing the IAQ score value when the RH is outside of a predetermined RH range; and decreasing the IAQ score value when the temperature is outside of a predetermined temperature range. 
     In further features, determining an IAQ score value includes at least one of: decreasing the IAQ score value as a first period that the amount of particulate has been greater than a predetermined amount of particulate increases; decreasing the IAQ score value as a second period that the amount of VOCs has been greater than a predetermined amount of VOCs increases; decreasing the IAQ score value as a third period that the amount of carbon dioxide has been greater than a predetermined amount of carbon dioxide increases; decreasing the IAQ score value as a fourth period that the RH has been outside of a predetermined RH range increases; and decreasing the IAQ score value as a fifth period that the temperature has been outside of a predetermined temperature range increases. 
     In a feature, a humidifier control system for a building is described. A humidity load module is 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, where the future predetermined period is after the first time. A humidification module is 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. A humidifier control module is 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. 
     In further features, 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. 
     In further features, 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. 
     In further features, 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. 
     In further features, 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. 
     In further features, an indoor air quality (IAQ) module of the building includes: 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. 
     In further features, 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. 
     In further features, 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. 
     In further features, the temperature of air within the building is a setpoint temperature within the building. 
     In further features, the RH of air within the building is a setpoint RH within the building. 
     In further features, the temperature of air within the building is an average air temperature within the building over the previous predetermined period. 
     In further features, the RH of air within the building is an average RH of air within the building over the previous predetermined period. 
     In a feature, a humidifier control system for a building is described. A humidity load module is configured to: obtain an outdoor ambient temperature at the building and an outdoor relative humidity (RH) at the building; and determine 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. A humidification module is configured to determine 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. A humidifier control module is configured to open a water feed valve of the humidifier in response to a determination that the humidification is less than the humidity load. 
     In a feature, a humidifier control method includes: 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, where 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. 
     In further features, 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. 
     In further features, 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. 
     In further features, 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. 
     In further features, 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. 
     In further features, the humidifier control method further includes: 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. 
     In further features, the humidifier control method further includes: 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. 
     In further features, the humidifier control method further includes: 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. 
     In further features, the temperature of air within the building is a setpoint temperature within the building. 
     In further features, the RH of air within the building is a setpoint RH within the building. 
     In further features, the temperature of air within the building is an average air temperature within the building over the previous predetermined period. 
     In further features, the RH of air within the building is an average RH of air within the building over the previous predetermined period. 
     In a feature, a humidifier control method includes: 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. 
     Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  is a block diagram of an example heating, ventilation, and air conditioning (HVAC) system; 
         FIG. 2A  is a functional block diagram of an air handler unit of an example HVAC system; 
         FIGS. 2B and 2C  are functional block diagrams of example condenser units of example HVAC systems; 
         FIG. 3  is a functional block diagram of an example indoor air quality (IAQ) sensor module that can be used with an HVAC system and/or other mitigation devices; 
         FIGS. 4A-4C  are a functional block diagram of an example IAQ control system; 
         FIG. 5A  is a functional block diagram of an example remote monitoring system; 
         FIG. 5B  is a functional block diagram of an example monitoring system; 
         FIGS. 6-9  are example user interfaces displayed by a user computing device during execution of an application based on data received from a remote monitoring system; 
         FIGS. 10A and 10B  include an example table of example sequences for activating control modes and mitigation devices for different combinations of conditions; 
         FIG. 11  includes a flowchart depicting an example method of mitigating IAQ parameters; 
         FIG. 12  includes an example table of compressor operation and blower speed for various humidity control modes; 
         FIG. 13  includes an example method of controlling a blower and a compressor based on relative humidity; 
         FIG. 14  includes an example table of compressor operation and blower speed for various humidity control modes; 
         FIG. 15  includes an example method of controlling a blower and a compressor based on relative humidity; 
         FIG. 16  includes a functional block diagram of an example implementation of a thermostat; and 
         FIGS. 17-18  include flowcharts depicting example methods of controlling operation of a humidifier. 
     
    
    
     In the drawings, reference numbers may be reused to identify similar and/or identical elements. 
     DETAILED DESCRIPTION 
     According to the present disclosure, an indoor air quality (IAQ) sensor module can be used with one or more mitigation devices of a residential or light commercial HVAC (heating, ventilation, and/or air conditioning) system of a building and/or one or more other mitigation devices. The IAQ sensor module includes one, more than one, or all of a temperature sensor, a relative humidity (RH) sensor, a particulate sensor, a volatile organic compound (VOC) sensor, and a carbon dioxide (CO2) sensor. The IAQ sensor module may also include one or more other IAQ sensors, such as occupancy, barometric pressure, light, sound, etc. The temperature sensor senses a temperature of air at the location of the IAQ sensor. The RH sensor measures a RH of air at the location of the IAQ sensor. The particulate sensor measures an amount (e.g., concentration) of particulate greater than a predetermined size in the air at the location of the IAQ sensor. The VOC sensor measures an amount of VOCs in the air at the location of the IAQ sensor. The carbon dioxide sensor measures an amount of carbon dioxide in the air at the location of the IAQ sensor. Other IAQ sensors would measure an amount of a substance or condition in the air at the location of the IAQ sensor. 
     Higher humidity in a building may increase the level of other IAQ parameters such as particulate matter (PM), VOCs, and carbon dioxide within the building. Operating an indoor fan air flow for circulation and ventilation to improve the above IAQ parameters may also increase humidity. There is a need for better control of the humidity range by combining dehumidification and humidification functions. An ideal range of humidity for IAQ may be between 40% and 50%. 
     The IAQ sensor module is wirelessly connected to a thermostat of the HVAC system, such as via a Bluetooth or WiFi. The IAQ sensor module may additionally or alternatively be wirelessly connected to a control module. The IAQ sensor module communicates measurements from its sensors, and optionally, a time and date to the thermostat and/or the control module. The control module and/or the thermostat controls operation of the mitigation devices based on the measurements from the IAQ sensor module. For example, the control module and/or the thermostat controls operation of the mitigation devices based on maintaining a temperature measured by the IAQ sensor module within a upper and lower temperature limits, based on maintaining a RH measured by the IAQ sensor within upper and lower RH limits, based on maintaining the amount of particulate in the air at the IAQ sensor module below a predetermined amount of particulate, based on maintaining the amount of VOCs in the air at the IAQ sensor module below a predetermined amount of VOCs, and/or based on maintaining the amount of carbon dioxide in the air at the IAQ sensor module below a predetermined amount of carbon dioxide. 
     The control module and/or the thermostat can provide information on the measurements of the IAQ sensor and other data (e.g., statuses of mitigation devices, local outdoor air conditions, etc.) to one or more user devices (e.g., of tenants, occupants, customers, contractors, etc.) associated with the building. For example, the building may be a single-family residence, and the customer may be the homeowner, a landlord, or a tenant. In other implementations, the building may be a light commercial building, and the customer may be the building owner, a tenant, or a property management company. 
     A humidifier control module controls operation of a humidifier of a building during heating to maintain RH within the building within a predetermined RH range and maintain other IAQ parameters less than respective predetermined values or within respective predetermined ranges. To this end, an IAQ score module determines an IAQ score of the air within the building based on the IAQ parameters. The IAQ score module may decrease the IAQ score when one or more of the IAQ parameters are outside of the respective predetermined ranges or greater than the respective predetermined values, and vice versa. After turning on the humidifier, the humidifier control module may maintain the humidifier on until the IAQ score stops improving (e.g., increasing) or until heating is discontinued (e.g., due to air temperature within the building becoming greater than a predetermined value). 
     The humidifier control module may additionally or alternatively predictively control operation of the humidifier based on a predicted humidity load of the building over a predetermined period in the future. The predicted humidity load corresponds to the amount of water to be added to the air within the building during the predetermined period to reach an RH setpoint. A humidification module may determine a predicted humidification of the building that may be provided by the humidifier over the predetermined period in the future based on how long the humidifier was on during a predetermined period prior to the future predetermined period and a predetermined evaporation rate of the humidifier. 
     When the predicted humidification is less than the predicted humidity load, the humidifier control module may turn the humidifier on more frequently and/or for a longer period before and/or during the future predetermined period. This may at least to some extent offset the predicted humidity load over the future predetermined period and prevent low RH situations from occurring before and during the future predetermined period. When the predicted humidification is greater than the predicted humidity load, the humidifier control module may maintain the humidifier off more frequently and/or for a longer period before and/or during the future predetermined period. This may at least to some extent offset the predicted humidity load over the future predetermined period and prevent high RH situations from occurring before and during the future predetermined period. 
     As used in this application, the term HVAC can encompass all environmental comfort systems in a building, including heating, cooling, humidifying, dehumidifying, and air exchanging and purifying, and covers devices such as furnaces, heat pumps, humidifiers, dehumidifiers, ventilators, and air conditioners. HVAC systems as described in this application do not necessarily include both heating and air conditioning, and may instead have only one or the other. 
     In split HVAC systems, an air handler unit is often located indoors, and a condensing unit is often located outdoors. In heat pump systems, the function of the air handler unit and the condensing unit are reversed depending on the mode of the heat pump. As a result, although the present disclosure uses the terms air handler unit and condensing unit, the terms indoor unit and outdoor unit could be used instead in the context of a heat pump. The terms indoor unit and outdoor unit emphasize that the physical locations of the components stay the same while their roles change depending on the mode of the heat pump. A reversing valve selectively reverses the flow of refrigerant from what is shown in  FIG. 1  depending on whether the system is heating the building or cooling the building in a heat pump system. When the flow of refrigerant is reversed, the roles of the evaporator and condenser are reversed—i.e., refrigerant evaporation occurs in what is labeled the condenser while refrigerant condensation occurs in what is labeled as the evaporator. 
     The control module and/or the thermostat upload data to a remote location. The remote location may be accessible via any suitable network, including the Internet. The remote location includes one or more computers, which will be referred to as servers. The servers execute a monitoring system on behalf of a monitoring company. Additionally or alternatively, a user computing device may serve as the monitoring system. The monitoring system receives and processes the data from the controller and/or thermostat of customers who have such systems installed. The monitoring system can provide performance information, diagnostic alerts, and error messages to one or more users associated with the building and/or third parties, such as designated HVAC contractors. 
     A server of the monitoring system includes a processor and memory. The memory stores application code that processes data received from the controller and/or the thermostat. The processor executes this application code and stores received data either in the memory or in other forms of storage, including magnetic storage, optical storage, flash memory storage, etc. While the term server is used in this application, the application is not limited to a single server. 
     A collection of servers may together operate to receive and process data from multiple buildings. A load balancing algorithm may be used between the servers to distribute processing and storage. The present application is not limited to servers that are owned, maintained, and housed by a monitoring company. Although the present disclosure describes diagnostics and processing and alerting occurring in a remote monitoring system, some or all of these functions may be performed locally using installed equipment and/or customer resources, such as on a customer computer or computers. 
     Customers and/or HVAC contractors may be notified of current and predicted issues (e.g., dirty filter) affecting effectiveness or efficiency of the HVAC system and/or the mitigating devices, and may receive notifications related to routine maintenance. The methods of notification may take the form of push or pull updates to an application, which may be executed on a smart phone, tablet, another type of mobile device, or on a computer (e.g., laptop or desktop). Notifications may also be viewed using web applications or on local displays, such as on the thermostat and/or other displays located throughout the building. Notifications may also include text messages, emails, social networking messages, voicemails, phone calls, etc. 
     Based on measurements from the control module, the thermostat, and/or the IAQ sensor module, the monitoring company can determine whether various components are operating at their peak performance. The monitoring company can advise the customer and a contractor when performance is reduced. This performance reduction may be measured for the system as a whole, such as in terms of efficiency, and/or may be monitored for one or more individual components. 
     In addition, the monitoring system may detect and/or predict failures of one or more components of the system. When a failure is detected, the customer can be notified and potential remediation steps can be taken immediately. For example, components of the HVAC system may be shut down to prevent or minimize damage, such as water damage, to HVAC components. A contractor can also be notified that a service call may be required. Depending on the contractual relationship between the customer and the contractor, the contractor may schedule a service call to the building. 
     The monitoring system may provide specific information to a contractor, such as identifying information of the customer&#39;s components, including make and model numbers, as well as indications of the specific part numbers of components. Based on this information, the contractor can allocate the correct repair personnel that have experience with the specific components and/or the system. In addition, a service technician is able to bring replacement parts, avoiding return trips after diagnosis. 
     Depending on the severity of the failure, the customer and/or contractor may be advised of relevant factors in determining whether to repair or replace some or all of the components. For example only, these factors may include relative costs of repair versus replacement, and may include quantitative or qualitative information about advantages of replacement equipment. For example, expected increases in efficiency and/or comfort with new equipment may be provided. Based on historical usage data and/or electricity or other commodity prices, the comparison may also estimate annual savings resulting from the efficiency improvement. 
     As mentioned above, the monitoring system may also predict impending failures. This allows for preventative maintenance and repair prior to an actual failure of components. Alerts regarding detected or impending failures reduce the time when the HVAC system is out of operation and allows for more flexible scheduling for both the customer and contractor. If the customer is out of town, these alerts may prevent damage from occurring when the customer is not present to detect the failure of a component. For example, failure of heating components of the HVAC system in winter may lead to pipes freezing and bursting. 
     Alerts regarding potential or impending failures may specify statistical timeframes before the failure is expected. For example only, if a sensor is intermittently providing bad data, the monitoring system may specify an expected amount of time before it is likely that the sensor effectively stops working due to the prevalence of bad data. Further, the monitoring system may explain, in quantitative or qualitative terms, how the current operation and/or the potential failure will affect operation of the HVAC system. This enables the customer to prioritize and budget for repairs. 
     For the monitoring service, the monitoring company may charge a periodic rate, such as a monthly rate. This charge may be billed directly to the customer and/or may be billed to the contractor. The contractor may pass along these charges to the customer and/or may make other arrangements, such as by requiring an up-front payment and/or applying surcharges to repairs and service visits. 
     The monitoring service allows the customer to remotely monitor real-time data within the building, outside of the building, and/or control components of the system, such as setting temperature and RH setpoints and other IAQ setpoints, enabling or disabling heating, cooling, ventilation, air purification, etc. In addition, the customer may be able to track usage data for components of the system and/or historical data. 
     In addition to being uploaded to the remote monitoring service (also referred to as the cloud), monitored data may be transmitted to a local device in the building. For example, a smartphone, laptop, or proprietary portable device may receive monitoring information to diagnose problems and receive real-time performance data. Alternatively, data may be uploaded to the cloud and then downloaded onto a local computing device, such as via the Internet from an interactive web site. 
     In  FIG. 1 , a block diagram of an example HVAC system is presented. In this particular example, a forced air system with a gas furnace is shown. Return air is pulled from the building through a filter  104  by a circulator blower  108 . The circulator blower  108 , also referred to as a fan, is controlled by a control module  112 . The control module  112  receives signals from a thermostat  116 . For example only, the thermostat  116  may include one or more temperature set points specified by the user. 
     The thermostat  116  may direct that the circulator blower  108  be turned on at all times or only when a heat request or cool request is present (automatic fan mode). In various implementations, the circulator blower  108  can operate at one or more discrete speeds or at any speed within a predetermined range. For example, the control module  112  may switch one or more switching relays (not shown) to control the circulator blower  108  and/or to select a speed of the circulator blower  108 . 
     The thermostat  116  provides the heat and/or cool requests to the control module  112 . When a heat request is made, the control module  112  causes a burner  120  to ignite. Heat from combustion is introduced to the return air provided by the circulator blower  108  in a heat exchanger  124 . The heated air is supplied to the building and is referred to as supply air. 
     The burner  120  may include a pilot light, which is a small constant flame for igniting the primary flame in the burner  120 . Alternatively, an intermittent pilot may be used in which a small flame is first lit prior to igniting the primary flame in the burner  120 . A sparker may be used for an intermittent pilot implementation or for direct burner ignition. Another ignition option includes a hot surface igniter, which heats a surface to a high enough temperature that, when gas is introduced, the heated surface initiates combustion of the gas. Fuel for combustion, such as natural gas, may be provided by a gas valve  128 . 
     The products of combustion are exhausted outside of the building, and an inducer blower  132  may be turned on prior to ignition of the burner  120 . In a high efficiency furnace, the products of combustion may not be hot enough to have sufficient buoyancy to exhaust via conduction. Therefore, the inducer blower  132  creates a draft to exhaust the products of combustion. The inducer blower  132  may remain running while the burner  120  is operating. In addition, the inducer blower  132  may continue running for a set period of time after the burner  120  turns off. 
     A single enclosure, which will be referred to as an air handler unit  136 , may include the filter  104 , the circulator blower  108 , the control module  112 , the burner  120 , the heat exchanger  124 , the inducer blower  132 , an expansion valve  140 , an evaporator  144 , and a condensate pan  146 . In various implementations, the air handler unit  136  includes an electrical heating device (not shown) instead of or in addition to the burner  120 . When used in addition to the burner  120 , the electrical heating device may provide backup or secondary (extra) heat to the burner  120 . 
     In  FIG. 1 , the HVAC system includes a split air conditioning system. Refrigerant is circulated through a compressor  148 , a condenser  152 , the expansion valve  140 , and the evaporator  144 . The evaporator  144  is placed in series with the supply air so that when cooling is desired, the evaporator  144  removes heat from the supply air, thereby cooling the supply air. During cooling, the evaporator  144  is cold (e.g., below the dew point of the air within the building), which causes water vapor to condense. This water vapor is collected in the condensate pan  146 , which drains or is pumped out. 
     A control module  156  receives a cool request from the control module  112  and controls the compressor  148  accordingly. The control module  156  also controls a condenser fan  160 , which increases heat exchange between the condenser  152  and outside air. In such a split system, the compressor  148 , the condenser  152 , the control module  156 , and the condenser fan  160  are generally located outside of the building, often in a single condensing unit  164 . 
     In various implementations, the control module  156  may include a run capacitor, a start capacitor, and a contactor or relay. In various implementations, the start capacitor may be omitted, such as when the condensing unit  164  includes a scroll compressor instead of a reciprocating compressor. The compressor  148  may be a variable-capacity compressor and may respond to a multiple-level cool request. For example, the cool request may indicate a mid-capacity call for cooling or a high-capacity call for cooling. The compressor  148  may vary its capacity according to the cool request. 
     The electrical lines provided to the condensing unit  164  may include a 240 volt mains power line (not shown) and a 24 volt switched control line. The 24 volt control line may correspond to the cool request shown in  FIG. 1 . The 24 volt control line controls operation of the contactor. When the control line indicates that the compressor should be on, the contactor contacts close, connecting the 240 volt power supply to the compressor  148 . In addition, the contactor may connect the 240 volt power supply to the condenser fan  160 . In various implementations, such as when the condensing unit  164  is located in the ground as part of a geothermal system, the condenser fan  160  may be omitted. When the 240 volt mains power supply arrives in two legs, as is common in the U.S., the contactor may have two sets of contacts, and can be referred to as a double-pole single-throw switch. 
     Typically, the thermostat  116  includes a temperature sensor and a relative humidity (RH) sensor. When in a heating (heat) mode, the thermostat  116  generates a heat request when the temperature measured by the temperature sensor is less than a lower temperature limit. When in a cooling (cool) mode, the thermostat  116  generates a cool request when the temperature measured by the temperature sensor is greater than an upper temperature limit. The upper and lower temperature limits may be set to a setpoint temperature+ and − a predetermined amount (e.g., 1, 2, 3, 4, 5 degrees Fahrenheit), respectively. The setpoint temperature may be set to a predetermined temperature by default and may be adjusted by a user. 
       FIGS. 2A-2B  are functional block diagrams of an example monitoring system associated with an HVAC system of a building. The air handler unit  136  of  FIG. 1  is shown for reference. The thermostat  116  of  FIG. 1  is a WiFi thermostat  208  having networking capability. 
     In many systems, the air handler unit  136  is located inside the building, while the condensing unit  164  is located outside the building. The present disclosure is not limited to that arrangement, however, and applies to other systems including, as examples only, systems where the components of the air handler unit  136  and the condensing unit  164  are located in close proximity to each other or even in a single enclosure. The single enclosure may be located inside or outside of the building. In various implementations, the air handler unit  136  may be located in a basement, garage, or attic. In ground source systems, where heat is exchanged with the earth, the air handler unit  136  and the condensing unit  164  may be located near the earth, such as in a basement, crawlspace, garage, or on the first floor, such as when the first floor is separated from the earth by only a concrete slab. 
     In  FIG. 2A , a transformer  212  can be connected to an AC line in order to provide AC power to the control module  112  and the thermostat  208 . For example, the transformer  212  may be a 10-to-1 transformer and therefore provide either a 12V or 24V AC supply depending on whether the air handler unit  136  is operating on nominal 120 volt or nominal 240 volt power. 
     The control module  112  controls operation in response to signals from the thermostat  208  received over control lines. The control lines may include a call for cool (cool request), a call for heat (heat request), and a call for fan (fan request). The control lines may include a line corresponding to a state of a reversing valve in heat pump systems. 
     The control lines may further carry calls for secondary heat and/or secondary cooling, which may be activated when the primary heating or primary cooling is insufficient. In dual fuel systems, such as systems operating from either electricity or natural gas, control signals related to the selection of the fuel may be monitored. Further, additional status and error signals may be monitored, such as a defrost status signal, which may be asserted when the compressor is shut off and a defrost heater operates to melt frost from an evaporator. 
     One or more of these control signals (on the control lines) is also transmitted to the condensing unit  164  (shown in  FIGS. 2B and 2C ). In various implementations, the condensing unit  164  may include an ambient temperature sensor that generates temperature data. When the condensing unit  164  is located outdoors, the ambient temperature represents an outside (or outdoor) ambient temperature. The temperature sensor supplying the ambient temperature may be located outside of an enclosure of the condensing unit  164 . Alternatively, the temperature sensor may be located within the enclosure, but exposed to circulating air. In various implementations the temperature sensor may be shielded from direct sunlight and may be exposed to an air cavity that is not directly heated by sunlight. Alternatively or additionally, online (including Internet-based) weather data based on the geographical location of the building may be used to determine sun load, outside ambient air temperature, relative humidity, particulate, VOCs, carbon dioxide, etc. 
     In  FIG. 2C , an example condensing unit  268  is shown for a heat pump implementation. The condensing unit  268  may be configured similarly to the condensing unit  164  of  FIG. 2B . Although referred to as the condensing unit  268 , the mode of the heat pump determines whether the condenser  152  of the condensing unit  268  is actually operating as a condenser or as an evaporator. A reversing valve  272  is controlled by a control module  276  and determines whether the compressor  148  discharges compressed refrigerant toward the condenser  152  (cooling mode) or away from the condenser  152  (heating mode). The control module  276  controls the reversing valve  272  and the compressor  148  based on the control signals. The control module  276  may receive power, for example, from the transformer  212  of the air handler unit  136  or via the incoming AC power line. 
       FIG. 3  includes a functional block diagram of an example indoor air quality (IAQ) sensor module  304  that can be used with an HVAC system and/or one or more other mitigation devices. The IAQ sensor module  304  includes one, more than one, or all of: a temperature sensor  308 , a relative humidity (RH) sensor  312 , a particulate sensor  316 , a volatile organic compounds (VOC) sensor  320 , and a carbon dioxide sensor  324 . The IAQ sensor module  304  may also include a sampling module  328  and a transceiver module  332 . 
     A power supply  336  may receive AC power from a standard wall outlet (or receptacle)  340  via a plug  344 . For example, the standard wall outlet  340  may provide nominal 120 volt or nominal 240 volt AC power. The power supply  336  may include an AC to direct current (DC) converter that converts the AC power into DC power, such as 5 volt, 12 volt, or 24 volt DC power. The power supply  336  supplies power to the components of the IAQ sensor module  304  including the sensors, the sampling module  328 , and the transceiver module  332 . While the example of the power supply  336  being integrated within the IAQ sensor module  304  is provided, the power supply  336  may be integrated with the plug  344  in various implementations. Also, while the example of the power supply  336  providing one DC voltage to the components of the IAQ sensor module  304 , the power supply  336  may provide two or more different DC voltages to different components of the IAQ sensor module  304 . 
     Additionally or alternatively, the power supply  336  may include one or more batteries or one or more solar cells that supply power to the components of the IAQ sensor module  304 . The one or more batteries may be replaceable or non-replaceable. In the example of the one or more batteries being non-replaceable, the one or more batteries may be re-chargeable, such as via a standard wall outlet. In this example, the IAQ sensor module  304  may include a charger that charges the one or more batteries using power supplied, for example, via a standard wall outlet. 
     The IAQ sensor module  304  is portable and can be moved into different rooms of a building. The IAQ sensor module  304  could also be placed outside the building, for example, to measure one or more conditions outside of the building, calibration, or for one or more other reasons. The temperature sensor  308  measures a temperature of air at the IAQ sensor module  304 . The RH sensor  312  measures a relative humidity of air at the IAQ sensor module  304 . The particulate sensor  316  measures an amount (e.g., a mass flow rate, such as micrograms (μg) per cubic meter) of particulate in air at the IAQ sensor module  304  having a diameter that is less than a predetermined size (e.g., 2.5 or 10 micrometers (μm)). The VOC sensor  320  measures an amount (e.g., parts per billion (ppb)) of VOC in air at the IAQ sensor module  304 . The carbon dioxide sensor  324  measures an amount (e.g., ppm) of carbon dioxide in air at the IAQ sensor module  304 . The included ones of the temperature sensor  308 , the RH sensor  312 , the particulate sensor  316 , the VOC sensor  320 , and the carbon dioxide sensor  324  will be referred to collectively as the IAQ sensors. 
     The sampling module  328  samples (analog) measurements of the IAQ sensors. The sampling module  328  may also digitize and/or store values of the measurements of the IAQ sensors. In various implementations, the IAQ sensors may be digital sensors and output digital values corresponding to the respective measured parameters. In such implementations, the sampling module  328  may perform storage or may be omitted. 
     The IAQ sensor module  304  may include one or more expansion ports to allow for connection of additional sensors and/or to allow connection to other devices. Examples of other devices include one or more other IAQ sensor modules, one or more other types of the IAQ sensors not included in the IAQ sensor module  304 , a home security system, a proprietary handheld device for use by contractors, a mobile computing device, and other types of devices. 
     The transceiver module  332  transmits frames of data corresponding to predetermined periods of time. Each frame of data may include the measurements of the IAQ sensors over a predetermined period. One or more calculations may be performed for the data of each frame of data, such as averaging the measurements of one or more of the IAQ sensors. Each frame (including the calculations and/or the measurements) may be transmitted to a monitoring system, as discussed further below. The measurements of the IAQ sensors may be sampled at a predetermined rate, such as 10 samples per minute or another suitable rate. Each frame may correspond to a predetermined number of sets of samples (e.g., 10). The monitoring system may provide visual representations of the measurements over predetermined periods of time along with other data, as discussed further below. 
     The transceiver module  332  transmits each frame (including the calculations and/or the measurements) to an IAQ control module  404  and/or the thermostat  208 . The transceiver module  332  transmits the frames wirelessly via one or more antennas, such as antenna  348 , using a proprietary or standardized, wired or wireless protocol, such as Bluetooth, ZigBee (IEEE 802.15.4), 900 Megahertz, 2.4 Gigahertz, WiFi (IEEE 802.11). The IAQ sensor module  304  may communicate directly with the IAQ control module  404  and/or the thermostat  208  or with a separate computing device, such as a smartphone, tablet, or another type of computing device. In various implementations, a gateway  408  is implemented, which creates a wireless network for the IAQ sensor module  304 , the IAQ control module  404 , and the thermostat  208 . The gateway  408  may also interface with a customer router  412  using a wired or wireless protocol, such as Ethernet (IEEE 802.3). 
     Referring now to  FIGS. 4A-4C , functional block diagrams of example IAQ control systems are presented. The IAQ control module  404  may communicate with the customer router  412  using WiFi. Alternatively, the IAQ control module  404  may communicate with the customer router  412  via the gateway  408 . The thermostat  208  may also communicate with the customer router  412  using WiFi or via the gateway  408 . In various implementations, the IAQ control module  404  and the thermostat  208  may communicate directly or via the gateway  408 . 
     The IAQ sensor module  304 , the IAQ control module  404 , and/or the thermostat  208  transmits data measured by the IAQ sensor module  304  and parameters of the IAQ control module  404  and/or the thermostat  208  over a wide area network  416 , such as the Internet (referred to as the Internet  416 ). The IAQ sensor module  304 , the IAQ control module  404 , and/or the thermostat  208  may access the Internet  416  using the customer router  412  of the customer. The customer router  412  may already be present to provide Internet access to other devices (not shown) within the building, such as a customer computer and/or various other devices having Internet connectivity, such as a DVR (digital video recorder) or a video gaming system. 
     The IAQ sensor module  304 , the IAQ control module  404 , and/or the thermostat  208  transmit the data to a remote monitoring system  420  via the Internet  416  using the customer router  412 . Further discussion of the remote monitoring system  420  is provided below. 
     The IAQ control module  404  and/or the thermostat  208  control operation (e.g., on, off, speed, etc.) of mitigation devices  424  based on the measurements from the IAQ sensor module  304 . For example, the measurements of the IAQ sensor module  304  may be provided to the thermostat  208  and the thermostat  208  may control operation of the mitigation devices  424  in various implementations (e.g.,  FIG. 4A ). The IAQ control module  404  can be omitted in such implementations. While the example of the thermostat  208  controlling the mitigation devices  424  will be discussed, alternatively the IAQ control module  404  may control operation of the mitigation devices  424  (e.g.,  FIG. 4B ), or the thermostat  208  and the IAQ control module  404  may together control the mitigation devices  424  (e.g.,  FIG. 4C ). 
     The IAQ control module  404  and/or thermostat  208  control and communicate with the mitigation devices  424  wirelessly, by wire, using a combination of wireless and wired connections. In the case of wireless control and communication, the IAQ control module  404 , the thermostat  208 , and the mitigation devices  424  include respective transceivers. 
     The mitigation devices  424  include: (i) the condensing unit  164 , (ii) the air handler unit  136  (e.g., the circulator blower  108 ), (iii) an air cleaner/purifier  428 , (iv) a humidifier  432 , (v) a dehumidifier  436 , and (vi) a ventilator  440 . The air cleaner/purifier  428  may be separate from the air handler unit  136  (e.g., a standalone air cleaner/purifier). In various implementations, the air handler unit  136  may serve as the air cleaner/purifier  428 . The air cleaner/purifier  428  draws in air and forces the air through a filter before expelling filtered air to the building. The filter may be rated (e.g., minimum efficiency reporting value, MERV) to remove a predetermined amount (e.g., 95%) of particulate of the size measured by the particulate sensor  316 . Operation of the air cleaner/purifier  428  may include whether the air cleaner/purifier  428  is on or off and, when on, a speed of the air cleaner/purifier  428 . The air cleaner/purifier  428  may have a single speed or multiple discrete speeds. 
     Operation of the air cleaner/purifier  428  may be controlled via wire or wirelessly by the thermostat  208 . Examples of wireless communication and control include, but are not limited to, Bluetooth connections and WiFi connections. For example only, the thermostat  208  may wirelessly control whether the air cleaner/purifier  428  is on or off and, if on, the speed of the air cleaner/purifier  428 . As one example, the thermostat  208  may turn the air cleaner/purifier  428  on when the amount of particulate measured by the particulate sensor  316  is greater than a first predetermined amount of particulate. The thermostat  208  may leave the air cleaner/purifier  428  on until the amount of particulate measured by the particulate sensor  316  is less than a second predetermined amount of particulate that is less than the first predetermined amount of particulate. The thermostat  208  may turn the air cleaner/purifier  428  off when the amount of particulate measured by the particulate sensor  316  is less than the second predetermined amount of particulate. In various implementations, the thermostat  208  may vary the speed of the air cleaner/purifier  428  based on the amount of particulate measured by the particulate sensor  316 . For example, the thermostat  208  may increase the speed of the air cleaner/purifier  428  as the amount of particulate increases and vice versa. 
     The humidifier  432  humidifies air within the building. The humidifier  432  may be included with the air handler unit  136  or a standalone humidifier. For example, when included with the air handler unit  136 , the humidifier  432  may add moisture to the supply air before the supply air is output from vents to the building. The humidifier  432  may add moisture to air, for example, by supplying water to a medium (e.g., a pad) and forcing air (e.g., supply air) through the hydrated medium. Alternatively, the humidifier  432  may spray water in the form of mist into air (e.g., supply air). In the example of a standalone humidifier, the humidifier  432  may spray water in the form of mist into air. Examples of humidifiers include drum type humidifiers (drained and drainless), evaporative pad humidifiers, and powered flow humidifiers, etc. 
       FIG. 1  includes an example implementation of the humidifier  432  with the air handler unit  136 , although other configurations are possible. The thermostat  208  controls water flow to the humidifier  432  (via opening of a water feed valve  434 , such as a solenoid valve) from a water system of the building. Standalone humidifiers  432  also include a water feed valve. For standalone humidifiers, the water feed valve  434  may control water flow from a water tank or reservoir. Some humidifiers also include a humidifier blower  435  that increases airflow to through the humidifier  432  (e.g., through an evaporative pad) to help facilitate humidification. 
     Operation of the humidifier  432  may include whether the humidifier  432  is on (the water feed valve  434  is open) or off (the water feed valve  434  is closed). In various implementations, operation of the humidifier  432  may also include a humidification rate (e.g., an amount of water supplied to the pad or into the air as mist or opening of the water feed valve  434 ). The humidifier  432  may be configured to provide only a single humidification rate or may be configured to provide multiple different humidification rates. 
     Operation of the humidifier  432  may be controlled via wire or wirelessly by the thermostat  208 . For example only, the thermostat  208  may control (by wire) whether the humidifier  432  included with the air handler unit  136  is on or off. As another example, if the humidifier  432  is implemented separately from the air handler unit  136 , the thermostat  208  may wirelessly control whether the humidifier  432  is on or off and a humidification rate when on. Examples of wireless communication include, but are not limited to, Bluetooth connections and WiFi connections. For example only, the thermostat  208  may turn the humidifier  432  on when the RH measured by the RH sensor  312  is less than a humidification RH setpoint. The thermostat  208  may leave the humidifier  432  on until the RH measured by the RH sensor  312  is greater than a second RH setpoint that is greater than the first RH setpoint. The thermostat  208  may turn the humidifier  432  off when the RH measured by the RH sensor  312  is greater than the second RH setpoint. Control of operation of the humidifier  432  is discussed further below. While the humidifier is shown in the example of  FIG. 1 , the humidifier  432  could also be implemented with the example of  FIG. 2A . As discussed above, the humidifier  432  may alternatively be a standalone humidifier. 
     The dehumidifier  436  dehumidifies (i.e., removes humidity from) air within the building. The dehumidifier  436  may be included with the air handler unit  136  or a standalone dehumidifier. For example, the dehumidifier  436  may draw moisture from the supply air (or add dry air to the supply air) before the supply air is output from vents to the building. Operation of the dehumidifier  436  may include whether the dehumidifier  436  is on or off. 
     Operation of the dehumidifier  436  may be controlled via wire or wirelessly by the thermostat  208 . For example only, the thermostat  208  may control (by wire) whether the dehumidifier  436  included with the air handler unit  136  is on or off. As another example, the thermostat  208  may wirelessly control whether the dehumidifier  436 , implemented as a standalone device, is on or off. For example only, the thermostat  208  may turn the dehumidifier  436  on when the RH measured by the RH sensor  312  is greater than a first dehumidification RH setpoint. The first dehumidification RH setpoint may be the same as the second RH setpoint or different than (e.g., greater than) the second RH setpoint. The thermostat  208  may leave the dehumidifier  436  on until the RH measured by the RH sensor  312  is less than a second dehumidification RH setpoint that is less than the first dehumidification RH setpoint. The thermostat  208  may turn the dehumidifier  436  off when the RH measured by the RH sensor  312  is less than the second dehumidification RH setpoint. The second dehumidification RH setpoint may be the same as the first RH setpoint or different than (e.g., greater than) the first RH setpoint. 
     The ventilator  440  vents air from within the building out of the building. This also passively draws air from outside of the building into the building. The ventilator  440  may be included with the air handler unit  136  (e.g., the inducer blower  132 ) or a standalone ventilator. Examples of standalone ventilators include blowers that blow air from within the building out of the building (e.g., range hoods fans, bathroom fans, the inducer blower, etc.). Operation of the ventilator  440  may include whether the ventilator  440  is on or off and, when on, a speed. The ventilator  440  may be configured to operate at a single speed or at multiple different speeds. 
     Operation of the ventilator  440  may be controlled via wire or wirelessly by the thermostat  208 . For example only, the thermostat  208  may wirelessly control whether the ventilator  440  is on or off and, if on, the speed of the ventilator  440 . As one example, the thermostat  208  may turn the ventilator  440  on when the amount of VOCs measured by the VOC sensor  320  is greater than a first predetermined amount of VOCs. The thermostat  208  may leave the ventilator  440  on until the amount of VOCs measured by the VOC sensor  320  is less than a second predetermined amount of VOCs that is less than the first predetermined amount of VOCs. The thermostat  208  may turn the ventilator  440  off when the amount of VOCs measured by the VOC sensor  320  is less than the second predetermined amount of VOCs. 
     As another example, the thermostat  208  may turn the ventilator  440  on when the amount of carbon dioxide measured by the carbon dioxide sensor  324  is greater than a first predetermined amount of carbon dioxide. The thermostat  208  may leave the ventilator  440  on until the amount of carbon dioxide measured by the carbon dioxide sensor  324  is less than a second predetermined amount of carbon dioxide that is less than the first predetermined amount of carbon dioxide. The thermostat  208  may turn the ventilator  440  off when the amount of carbon dioxide measured by the carbon dioxide sensor  324  is less than the second predetermined amount of carbon dioxide. 
     The mitigation devices described above are only described as example. One or more of the example mitigation devices may be omitted. One or more other types of mitigation devices may be included. Additionally, while the example of only one of each type of mitigation device is provided, two or more of a given type of mitigation device may be included and controlled. 
     Changes in temperature and/or humidity also cause changes in particulate, VOCs, and/or carbon dioxide. For example, a change in temperature may cause a change in VOCs, RH, particulate, and/or carbon dioxide. As another example, a change in RH may cause a change in particulate, VOCs, and/or carbon dioxide. For example, particulate may increase as RH increases and vice versa. 
     The thermostat  208  therefore controls operation of the mitigation devices  424  based on one, more than one, or all of the parameters measured by the IAQ sensor module  304  in an attempt to: adjust the temperature within a predetermined temperature range, adjust the RH within a predetermined RH range, adjust the amount of particulate (if measured) to less than a predetermined amount of particulate, adjust the amount of VOCs (if measured) to less than a predetermined amount of VOCs, and to adjust the amount of carbon dioxide (if measured) to less than a predetermined amount of carbon dioxide. 
       FIG. 5A  includes a functional block diagram of an example monitoring system. In  FIG. 5A , the IAQ control module  404  and/or the thermostat  208  are shown transmitting, using the customer router  412 , data to the remote monitoring system  420  via the Internet  416 . In other implementations, the IAQ control module  404  and/or the thermostat  208  may transmit the data to an external wireless receiver. The external wireless receiver may be a proprietary receiver for a neighborhood in which the building is located, or may be an infrastructure receiver, such as a metropolitan area network (such as WiMAX), a WiFi access point, or a mobile phone base station. 
     The remote monitoring system  420  includes a monitoring server  508  that receives data from the IAQ control module  404  and/or the thermostat  208  and maintains and verifies network continuity with the IAQ control module  404  and/or the thermostat  208 . The monitoring server  508  executes various algorithms to store setpoints for the building and to store measurements from the thermostat  208  and/or the IAQ sensor module  304  taken over time. 
     The monitoring server  508  may notify a review server  512  when one or more predetermined conditions are satisfied. This programmatic assessment may be referred to as an advisory. Some or all advisories may be triaged by a technician to reduce false positives and potentially supplement or modify data corresponding to the advisory. For example, a technician device  516  operated by a technician may be used to review the advisory and to monitor data (in various implementations, in real-time) from the IAQ control module  404  and/or the thermostat  208  via the monitoring server  508 . 
     A technician using the technician device  516  may review the advisory. If the technician determines that a problem or fault is either already present or impending, the technician instructs the review server  512  to send an alert to a customer device  524  that is associated with the building. The technician may be determine that, although a problem or fault is present, the cause is more likely to be something different than specified by the automated advisory. The technician can therefore issue a different alert or modify the advisory before issuing an alert based on the advisory. The technician may also annotate the alert sent to the customer device  524  with additional information that may be helpful in identifying the urgency of addressing the alert and presenting data that may be useful for diagnosis or troubleshooting. 
     In various implementations, minor problems may not be reported to the customer device  524  so as not to alarm the customer or inundate the customer with alerts. The review server  512  (or a technician) may determine whether a problem is minor based on a threshold. For example, an efficiency decrease greater than a predetermined threshold may be reported to the customer device  524 , while an efficiency decrease less than the predetermined threshold may not be reported to the customer device  524 . 
     In various implementations, the technician device  516  may be remote from the remote monitoring system  420  but connected via a wide area network. For example only, the technician device  516  may include a computing device such as a laptop, desktop, smartphone, or tablet. 
     Using the customer device  524  executing an application, the customer can access a customer portal  528 , which provides historical and real-time data from the IAQ control module  404  and/or the thermostat  208 . The customer portal  528  may also provide setpoints and predetermined ranges for each of the measurements, local outdoor air quality data, statuses of the mitigation devices  424  (e.g., on or off), and other data to the customer device  524 . Via the customer device  524 , the customer may change the setpoints and predetermined ranges. The monitoring server  508  transmits changed setpoints and predetermined ranges to the thermostat  208  and/or the IAQ control module  404  for use in controlling operation of the mitigation devices  424 . 
     The remote monitoring system  420  includes a local data server  520  that obtains local data at (outside) the building. The local data server  520  may obtain the local data from one or more local data sources  532  via a wide area network, such as the internet  416 , using a geographical location of the building. The geographical location may be, for example, an address, zip code, coordinates, or other geographical identifier of the building. The remote monitoring system  420  may obtain the geographical location of the building, for example, via the customer device  524  before providing data to the customer device  524 . The local data includes, for example, air temperature within a predetermined geographical area including the geographical location of the building, RH within the predetermined geographical area, amount of VOCs in the air within the predetermined geographical area, amount of particulate of the predetermined size measured by the particulate sensor  316  within the predetermined geographical area, and amount of carbon dioxide within the predetermined geographical area. 
       FIG. 5B  includes a functional block diagram of an example monitoring system where the customer device  524  serves as a monitoring system and provides the functionality of the remote monitoring system  420 . The thermostat  208  and/or the IAQ control module  404  transmit data to the customer device  524  wirelessly, such as via a Bluetooth connection, WiFi, or another wireless connection. The customer device  524  may obtain the local data from the local data sources  532  via a wide area network, such as the internet  416 . Alternatively, the IAQ control module  404  or the thermostat  208  may serve as a monitoring system and provide the functionality of the remote monitoring system  420 . 
       FIG. 6  includes an example user interface displayed by the customer device  524  during execution of the application based on data from the customer portal  528 . It should be understood that the following functions are performed by the customer device  524  during execution of the application. 
     As shown in  FIG. 6 , the customer device  524  may display real-time values of the temperature, RH, amount of VOCs, amount of particulate, and amount of carbon dioxide (CO2) measured by the IAQ sensor module  304 . In  FIG. 6 , these are illustrated in the row labeled “indoor” as they represent parameters within the building. The real-time values may be received by the customer device  524  from the monitoring server  508  via the customer portal  528 . 
     The customer device  524  may also display real-time values of the temperature, RH, amount of VOCs, amount of particulate, and amount of carbon dioxide (CO2) measured outside of the building but within the predetermined geographical area including the geographical area of the building. In  FIG. 6 , these are illustrated in the row labeled “outdoor” as they represent parameters outside of the building. The real-time values may be received by the customer device  524  from the monitoring server  508  via the customer portal  528 . 
     The customer device  524  may also display present setpoints for beginning heating (Heat) of the building, cooling (Cool) of the building, humidification (Humidify), dehumidification (Dehumidify), VOC removal (VOCs), particulate removal (Particulate), and carbon dioxide removal (Carbon Dioxide). In  FIG. 6 , these setpoints are illustrated in the row labeled “setpoints” as they represent setpoints for beginning associated mitigation actions within the building. The present setpoints may be received by the customer device  524  from the monitoring server  508  via the customer portal  528 . 
     A predetermined range for a measurement may be set based on the setpoint for a measurement. For example, a predetermined range for heating may be set to the temperature setpoint for heating plus and minus a predetermined amount. A predetermined range for cooling may be set to the temperature setpoint for cooling plus and minus a predetermined amount. The predetermined amount may be user adjustable in various implementations. 
     The customer device  524  also allows a user to adjust one or more of the present setpoints via the customer device  524 . For example, the customer device  524  may provide positive and negative adjustment inputs in association with one, more than one, or all of the setpoints to allow for adjustment of the present setpoints.  FIG. 6  includes the example of +serving as the positive adjustment input and −serving as the negative adjustment input. Adjustment inputs labeled and provided differently, however, may be used. 
     In response to receipt of input indicative of user interaction (e.g., touching, clicking, etc.) with an adjustment input associated with a setpoint, the customer device  524  may transmit a command to the monitoring server  508  to adjust (i.e., increment or decrement) the setpoint by a predetermined amount. For example, in response to receipt of input indicative of user interaction (e.g., touching, clicking, etc.) with the positive adjustment input associated with the heating temperature setpoint, the customer device  524  may transmit a command to the monitoring server  508  to increment the heating temperature setpoint by a first predetermined amount. In response to receipt of input indicative of user interaction (e.g., touching, clicking, etc.) with the negative adjustment input associated with the heating temperature setpoint, the customer device  524  may transmit a command to the monitoring server  508  to decrement the heating temperature setpoint by the first predetermined amount. As another example, in response to receipt of input indicative of user interaction (e.g., touching, clicking, etc.) with the positive adjustment input associated with the humidification RH setpoint, the customer device  524  may transmit a command to the monitoring server  508  to increment the humidification RH setpoint by a second predetermined amount. In response to receipt of input indicative of user interaction (e.g., touching, clicking, etc.) with the negative adjustment input associated with the humidification RH setpoint, the customer device  524  may transmit a command to the monitoring server  508  to decrement the humidification RH setpoint by the second predetermined amount. 
     The monitoring server  508  relays (transmits) received commands for adjusting setpoints to the thermostat  208  and/or the IAQ control module  404  via the internet  416 . Alternatively, the customer device  524  may transmit commands for adjusting setpoints to the thermostat  208  and/or the IAQ control module  404  directly or via the internet  416 . The thermostat  208  and/or the IAQ control module  404  adjust the associated setpoints in response to the commands received from the monitoring server  508 . 
     As discussed above, one or more than one IAQ sensor module  304  may be concurrently used within the building, such as in different rooms of the building.  FIG. 7  includes an example user interface displayed by the customer device  524  during execution of the application when the building includes multiple IAQ sensor modules. In the example of  FIG. 7 , the measurements from each IAQ sensor module are shown in a separate column. 
     As also discussed above, one or more of the IAQ sensors may be omitted from an IAQ sensor module. For example, as shown in the right-most column of  FIG. 7 , the associated IAQ sensor module only includes a particulate sensor and a carbon dioxide sensor. The temperature, relative humidity, and VOCs of zero may indicate that the IAQ sensor module does not include a temperature sensor, a humidity sensor, or a VOC sensor in the example of  FIG. 7 . 
       FIG. 8  includes an example user interface displayed by the customer device  524  during execution of the application based on additional data indicative of present statuses of control modes and present (operation) statuses of various devices and modes of devices of the building. The present statuses may be, for example, on or off. The present status of a control mode, device, or mode of a device may be on (currently in use) or off (not currently in use). One type of indicator may be used to indicate a present status of on, while another type of indicator may be used to indicate a present status of off. The customer device  524  may display the additional data concurrently with the data from one or more IAQ modules, the local data, and/or the setpoint data. 
     The customer device  524  selectively displays measurements of one or more IAQ sensor modules, local data, control modes, and/or statuses from a predetermined period of time. The predetermined period of time may be, for example, the present day, a predetermined number of days (including or not including the present day), a predetermined number of hours before a present time, a predetermined number of minutes before the present time, or another suitable period. By default, a predetermined period may be selected (e.g., the present day), but a user may select a different predetermined period and the customer device  524  may display the data for the selected predetermined period. 
       FIG. 9  includes an example user interface displayed by the customer device  524  during execution of the application for the present day (from 12:01 pm of the present day to the present time (approximately 10 pm in this example)). The customer device  524  displays data selected by a user of the customer device  524 . By default, all data may be selected, but a user may select less than all of the data to be displayed, and the customer device  524  may display only the selected data. 
     For example, in  FIG. 9 , only outdoor temperature (from the local data), outdoor RH (from the local data), indoor temperature (from the IAQ sensor module  304 ), indoor RH (from the IAQ sensor module  304 ), and particulate (from the IAQ sensor module  304 ) are graphed over time. Indicators of the statuses of the cooling mode, the heating mode, and use of the circulator blower  108  are also concurrently shown over time. Indoor Carbon dioxide (from the IAQ sensor module  304 , if measured) and indoor VOCs (from the IAQ sensor module  304 , if measures) are not graphed over time in this example. 
     The customer device  524  selectively displays a user interface for user selection of a priority for mitigating deviations in IAQ parameters. For example, the customer device  524  may display a user interface that allows user assignment of an order of prioritization for: (i) temperature control: (ii) RH control; (iii) particulate control; (vi) VOC control; and (v) carbon dioxide control. Temperature control may refer to maintaining, as much as possible, the temperature within the building within a predetermined temperature range. RH control may refer to maintaining, as much as possible, the RH within the building within a predetermined RH range. Particulate control may refer to maintaining, as much as possible, the amount of particulate within the building less than a predetermined amount of particulate. VOC control may refer to maintaining, as much as possible, the amount of VOCs within the building less than a predetermined amount of VOCs. Carbon dioxide control may refer to maintaining, as much as possible, the amount of carbon dioxide within the building less than a predetermined amount of carbon dioxide. The order of prioritization for (i)-(v) may be initially preset, but may be user selected/adjusted, as stated above. 
     The thermostat  208  and/or the IAQ control module  404  may control the mitigation devices  424  based on the prioritization (order). For example, when particulate control is the first priority, the thermostat  208  may control the mitigation devices  424  to decrease particulate as quickly as possible as opposed to, for example, controlling the mitigation devices  424  to more quickly adjust temperature or RH or to more quickly decrease the amount of VOCs and/or the amount of carbon dioxide. 
     The user interfaces provided by the customer device  524  provide visual information to the user regarding real-time measurements, historical measurements over a period of time, trends, and efficacy of IAQ mitigation and control. The user interfaces also enable the user to adjust setpoints to be used to control the mitigation devices  424  to control comfort and IAQ within the building. The user interfaces also enable the user to adjust prioritization in which IAQ conditions are mitigated. All of the above improves IAQ within the building and user experience regarding IAQ within the building. 
     As discussed above, RH and temperature both affect the amount of VOCs, the amount of carbon dioxide, and the amount of particulate. The thermostat  208  and/or IAQ control module  404  controls the mitigation devices  424  to mitigate deviations of the temperature outside of the predetermined temperature range and deviations of the RH outside of the predetermined RH range. When at least one of the temperature is outside of the predetermined temperature range and the RH is outside of the predetermined RH range, the thermostat  208  sequences execution of ones of the control modes based on the prioritization when one or more of the following are also true: the amount of particulate is greater than the predetermined amount of particulate, the amount of VOCs is greater than the predetermined amount of VOCs, and the amount of carbon dioxide is greater than the predetermined amount of carbon dioxide. The thermostat  208  controls the mitigation devices  424  based on the control modes. 
     The control modes includes the cooling mode, the heating mode, an extra heating mode, a humidify mode, a dehumidify mode, an extra dehumidify mode, a Departicle (or remove particulate) mode, a DeCO2 (or remove carbon dioxide) mode, an extra DeCO2 mode, a DeVOC (or remove VOC) mode, and an extra DeVOC mode. The thermostat  208  and/or IAQ control module  404  activates only one of the control modes at a time and determines a sequence for activating control modes when at least one of (I) and (II) is true and at least one of (A), (B), and (C) is true: 
     (I) the temperature is outside of the predetermined temperature range for heating or the predetermined temperature range for cooling; and 
     (II) the RH is outside of the predetermined RH range; and 
     (A) the amount of particulate is greater than the predetermined amount of particulate; 
     (B) the amount of VOCs is greater than the predetermined amount of VOCs; and 
     (C) the amount of carbon dioxide is greater than the predetermined amount of carbon dioxide. 
     The thermostat  208  and/or the IAQ control module  404  also activates an associated one of the control modes when one of (I), (II), (A), (B), and (C) is true and the other ones of (I), (II), (A), (B), and (C) are not true and when two or more of (I), (II), (A), (B), and (C) are true and the other ones of (I), (II), (A), (B), and (C) are not true. 
     When the heating mode is active, the thermostat  208  and/or IAQ control module  404  operates the burner  120  and/or the heat pump to generate heat. The thermostat  208  also operates the blower  108  at a predetermined speed, such as a predetermined medium speed when the heating mode is active. The heating mode may be activated when the temperature is less than the lower temperature limit of the predetermined temperature range for heating. 
     When the extra heating mode is active, the thermostat  208  and/or IAQ control module  404  may additionally (to the burner  120  and/or the heat pump and the blower  108 ) operate an electric heater to generate additional heat. The extra heating mode may be activated when the temperature is less than the lower temperature limit of the predetermined temperature range for heating continuously for greater than a predetermined period, such as 30 minutes or another suitable predetermined period. The heating mode and the extra heating mode may be deactivated when the temperature becomes greater than the upper temperature limit of the predetermined temperature range for heating. 
     When the cooling mode is active, the thermostat  208  and/or IAQ control module  404  operates the condensing unit  164 . In the example of a heat pump, the thermostat  208  may switch the reversing valve  272  to provide cooling. The thermostat  208  also operates the blower  108  at a predetermined speed, such as a predetermined high speed when the cooling mode is active. The predetermined high speed is greater than the predetermined medium speed. The cooling mode may be activated when the temperature is greater than the upper temperature limit of the predetermined temperature range for cooling. The cooling mode may be deactivated when the temperature becomes less than the lower temperature limit of the predetermined temperature range for cooling. 
     When the humidify mode is active, the thermostat  208  and/or control module  404  operates the humidifier  432 . The thermostat  208  also operates the blower  108  at a predetermined speed, such as the predetermined high speed when the humidify mode is active. The humidify mode may be activated when the RH is less than the first RH setpoint. The humidify mode may be deactivated when the RH becomes greater than the second RH setpoint. Other options for humidification without the use of the humidifier  432  are discussed below. 
     When the dehumidify mode is active, the thermostat  208  and/or IAQ control module  404  may operate the dehumidifier  436 . Additionally or alternatively, the thermostat  208  may toggle operation of the blower  108  between operation at a predetermined low speed for a predetermined period and the predetermined high speed for the predetermined period when the dehumidify mode is active. The dehumidify mode may be activated when the RH is greater than the first dehumidification RH setpoint. The predetermined period may be, for example, 5 minutes or another suitable period. 
     When the extra dehumidify mode is active, the thermostat  208  and/or IAQ control module  404  may also operate the blower  108  at the predetermined high speed. The thermostat  208  may additionally operate the compressor  148  and/or an electric heater to provide more rapid dehumidification when the extra dehumidify mode is active. Additionally or alternatively, the thermostat  208  may transition to the cooling mode. The dehumidify mode may be activated when the RH is at least a predetermined amount (e.g., 1 percent) greater than the second dehumidification RH setpoint. The dehumidify mode and the extra dehumidify may be deactivated when the RH becomes less than the second dehumidification RH setpoint. 
     When the Departicle mode is active, the thermostat  208  and/or IAQ control module  404  may operate the blower  108  at a predetermined speed, such as the predetermined high speed. Additionally or alternatively, the thermostat  208  may operate the air cleaner/purifier  428  when the Departicle mode is active. The Departicle mode may be activated when the amount of particulate is greater than the predetermined amount of particulate. The Departicle mode may be deactivated when the amount of particulate becomes less than the predetermined amount of particulate. 
     When the DeVOC mode is active, the thermostat  208  and/or IAQ control module  404  may operate the inducer blower  132  at a predetermined speed, such as the predetermined low speed. Additionally or alternatively, the thermostat  208  may operate one or more ventilators, such as one or more bathroom fans or range hood fans. The DeVOC mode may be activated when the amount of VOCs is greater than the predetermined amount of VOCs. 
     When the extra DeVOC mode is active, the thermostat  208  and/or IAQ control module  404  may operate the blower  108  at the predetermined high speed. The thermostat  208  may additionally operate one or more other ventilators to more rapidly decrease VOCs the extra DeVOC mode is active. The extra DeVOC mode may be activated when the amount of VOCs remains greater than the predetermined amount of VOCs for greater than a predetermined period when the DeVOC mode is active, such as 1 hour. The extra DeVOC mode and the DeVOC may be deactivated when the amount of VOCs becomes less than the predetermined amount of VOCs. 
     When the DeCO2 mode is active, the thermostat  208  and/or IAQ control module may operate the blower  108  at a predetermined speed, such as the predetermined low speed. Additionally or alternatively, the thermostat  208  may operate one or more ventilators, such as one or more bathroom fans or range hood fans. The DeCO2 mode may be activated when the amount of carbon dioxide is greater than the predetermined amount of carbon dioxide. 
     When the extra DeCO2 mode is active, the thermostat  208  and/or IAQ control module  404  may operate the blower  108  at the predetermined high speed. The thermostat  208  may additionally operate one or more other ventilators to more rapidly decrease carbon dioxide the extra DeCO2 mode is active. The extra DeCO2 mode may be activated when the amount of carbon dioxide remains greater than the predetermined amount of carbon dioxide for greater than a predetermined period when the DeCO2 mode is active, such as 1 hour. The extra DeCO2 mode and the DeCO2 may be deactivated when the amount of carbon dioxide becomes less than the predetermined amount of carbon dioxide. 
     When at least one of (A), (B), and (C) is satisfied and at least one of (I) and (II) is satisfied, the thermostat  208  and/or IAQ control module  404  determines the sequence for the control modes based on the prioritization of modes and the conditions that are satisfied, as discussed above. As discussed above, the prioritization may be set to a predetermined prioritization by default, but the user may adjust the prioritization via the customer device  524 . 
       FIGS. 10A and 10B  include a table of example sequences for activating ones of the control modes when different combinations of conditions are present given a prioritization. Example ranges are provided for temperature and RH, and example predetermined amounts are provided for particulate, VOCs, and carbon dioxide. 
     In the column headed “temp”, a lack of Temp+ or Temp− indicates that the temperature is between the upper and lower temperature limits. Temp+ in the example of  FIGS. 10A and 10B  indicates that the temperature is greater than the upper temperature limit. Temp− indicates that the temperature is less than the lower temperature limit. 
     In the example provided, one predetermined RH range (e.g., defined by the first RH setpoint and the second RH setpoint) is used for humidification and de-humidification. In the column headed “RH”, a lack of RH+ or RH− indicates that the RH is within a predetermined range (e.g., between the first RH setpoint and the second RH setpoint). RH+ is used to indicate that the RH is above the predetermined RH range (e.g., greater than the second RH setpoint). RH− is used to indicate that the RH is below the predetermined RH range (e.g., less than the first RH setpoint). 
     In the column headed “PM2.5”, a lack of PM2.5 indicates that the amount of particulate is less than the predetermined amount of particulate. PM2.5 indicates that the amount of PM is greater than the predetermined amount of particulate. VOC indicates that the amount of VOCs is greater than the predetermined amount of VOCs. In the column headed “VOC”, a lack of VOC indicates that the amount of VOCs is less than the predetermined amount of VOCs. In the column headed “CO2”, a lack of CO2 indicates that the amount of carbon dioxide is less than the predetermined amount of carbon dioxide. CO2 indicates that the amount of carbon dioxide is greater than the predetermined amount of carbon dioxide. 
     Example sequences of control modes used to mitigate a given set of conditions are provided in a time based order. For example, control modes listed under the column headed “Mode 1” would be performed temporally before control modes listed under the columns headed “Mode 2”, “Mode 3”, “Mode 4”, and “Mode 5”. As another example, control modes listed under the column headed “Mode 2” would be performed temporally before control modes listed under the columns headed “Mode 3”, “Mode 4”, and “Mode 5”. The lack of a control mode in a given column, however, does not indicate the existence of a significant period between the use of control modes. The lack of a control mode in a given column simply indicates the non-use of the associated control mode when mitigating the then present conditions. “Cool” indicates the cooling mode, while “Heat” indicates the heating mode. “Dehumidify” indicates the Dehumidify mode, “Humidify” indicates the humidify mode, PM indicates the Departicle mode, and VOC/CO2 indicates the DeVOC or the DeCO2 mode. In various implementations, the DeVOC and DeCO2 modes may be considered a single control mode because mitigation may be accomplished via operation of the same mitigation devices. The control modes labeled “extra”, such as the extra DeVOC mode or the extra heat mode may be automatically activated by the thermostat  208  as described above after a predetermined period of operation in the associated (non-extra) control mode, such as the DeVOC mode. 
     Generally speaking, the thermostat  208  determines whether (I), (II), (A), (B), or (C) is satisfied. For example, (I), (A), and (C) may be satisfied at a given time while (II) and (B) are not satisfied. If at least one of (I), (II), (A), (B), and (C) is satisfied, the thermostat  208  determines the sequence for mitigating the satisfied ones of (I), (II), (A), (B), and (C) given the prioritization. 
     The example of  FIGS. 10A and 10B  illustrate the example prioritization of: first priority is temperature (e.g., cool mode then heat mode); second priority is RH (e.g., dehumidify mode then humidify mode); third priority is Departicle mode; and fourth priority is VOCs and carbon dioxide (e.g., DeVOC mode and DeCO2 mode). In the example of (I), (A), and (C) being satisfied while (II) and (B) are not satisfied and the example prioritization, the thermostat  208  may determine to first activate the heat or cool mode and to heat or cool the building, second activate the Departicle mode and remove particulate from the air within the building, and third activate the DeVOC or DeCO2 mode and remove VOCs and/or carbon dioxide from the air within the building. This mitigates (I), (A), and (C) and first brings the temperature within the predetermined temperature range, second brings the amount of particulate below the predetermined amount of particulate, and third, brings the amount of VOCs or carbon dioxide below the predetermined amount of VOCs or the predetermined amount of carbon dioxide. 
     Indicators under the columns headed “fan” indicate operation of the blower  108 . The blower  108  may operate at multiple different speeds. For example, “L-Hx30s” indicates the above described toggling of the blower  108  between the predetermined low and high speeds for a predetermined period. “Medium” indicates the use of the predetermined medium speed, “low” indicates the use of the predetermined low speed, and “high” indicates the use of the predetermined high speed. The indicator “ON 20S-OFF 40s” under the columns headed “Elec Heat” indicates toggling between the electric heater being on for a predetermined period (e.g., 20 seconds) and off for a predetermined period (e.g., 40 seconds). For example, “L-Hx30s” indicates the above described toggling of the blower  108  between the predetermined low and high speeds for a predetermined period. 
       FIG. 11  includes a flowchart depicting an example method of mitigating multiple IAQ parameters. The example of  FIG. 11  illustrates a sequence for mitigating VOC and/or carbon dioxide before mitigating particulate matter then mitigating RH. The mitigation sequence can be configured, for example, based on user input regarding the mitigation sequence. Control begins with  1104  where the thermostat  208  may determine whether the amount of carbon dioxide is greater than the predetermined amount of carbon dioxide. If  1104  is true, the thermostat  208  operates one or more ventilation devices, such as the ventilator  440 , on a predetermined speed such as a predetermined high speed at  1108 , and control returns to  1104 . The operation of the one or more ventilation devices introduces fresh air into the building, thereby decreasing carbon dioxide within the air. If  1108  is true, control continues with  1112 . 
     At  1112 , the thermostat  208  determines whether the amount of VOCs is greater than the predetermined amount of VOCs. If  1112  is true, control continues with  1108  as discussed above. The operation of the one or more ventilation devices introduces fresh air into the house, thereby decreasing VOCs within the air. If  1112  is false, control continues with  1116 . At  1116 , the thermostat  208  determines whether the amount of particulate within the building is greater than the predetermined amount of particulate. If  1116  is false, control transfers to  1124 , which is discussed further below. If  1116  is true, control continues with  1120 . 
     At  1120 , the thermostat  208  determines whether the amount of particulate in the air outside the building is greater than the predetermined amount of particulate. The local data server  520  determines the amount of particulate in the air outside the building based on the geographical location of the building. If  1120  is false, control continues with  1108  as discussed above. The operation of the one or more ventilation devices brings fresh air into the house, decreasing the amount of particulate in the air. If  1120  is true, control continues with  1128  or optionally  1124 . 
     At optional  1124 , the thermostat  208  determines whether a temperature difference within the building is greater than a predetermined value (temperature). The predetermined value may be calibratable and may be set to, for example, approximately 2° F. or another suitable value. The thermostat  208  determines the temperature difference with the building based on the difference between: (i) a highest temperature measured by one of the IAQ sensor modules and the thermostat  208 ; and (ii) a lowest temperature measured by one of the IAQ sensor modules and the thermostat  208 . This provides a greatest difference in temperature between different locations where temperature is measured within the building. If  1124  is true, control transfers to  1128 . If  1124  is false, control may return to  1104 . In various implementations,  1124  may be omitted. 
     At  1128 , the thermostat  208  operates the blower  108  at a predetermined speed, such as the predetermined high speed. Control continues with  1132 . At  1132 , the thermostat  208  determines whether the RH is greater than the predetermined RH range (e.g., the second RH setpoint or the first dehumidification RH setpoint). If  1132  is true, the thermostat  208  operates the dehumidifier  436  at  1136 , and control returns to  1104 . In various implementations, the thermostat  208  may operate one or more other devices to dehumidify the air with the building, such as operate the electric heater, the compressor  148 , and/or one or more other mitigation devices that dehumidify air within the building. If  1132  is false, control continues with  1140 . 
     At  1140 , the thermostat  208  determines whether the RH is less than the predetermined RH range (e.g., the first RH setpoint or the second dehumidification RH setpoint). If  1140  is true, thermostat  208  operates the humidifier  432  at  1144 , and control returns to  1104 . In various implementations, the thermostat  208  may operate one or more other mitigation devices to humidify the air within the building. If  1132  is false, control returns to  1104 . 
     In various implementations, the blower  108  can serve as a humidifier and a dehumidifier when the condensing unit  164  is being used (i.e., the compressor  148  is on) to cool the air within the building. More specifically, circulating the air within the building dehumidifies the air within the building. During cooling, condensation collects on the evaporator  144  and in the condensate pan  146 . Via the blower  108 , the condensation can be used to humidify the air within the building. 
     In various implementations, the IAQ control module  404  is configured to control a speed of the blower  108  to humidify or dehumidify the air within the building. While the example of the IAQ control module  404  being configured to control the speed of the blower  108  is provided, the thermostat  208  may be configured to control the speed of the blower  108 , as discussed further below, or another blower control module may be configured to control the speed of the blower  108 . 
     Although not shown in  FIG. 11 , it is assumed the thermostat will control temperature within the building based on the temperature set point. When the temperature of the air within the building is greater than the lower temperature limit for cooling, the thermostat  208  generates a cooling request. More specifically, the thermostat  208  generates the control signals to apply power to the compressor  148  and the condenser fan  160  via the control module  156  or  276 . When the cooling request is received from the thermostat  208 , the IAQ control module  404  determines a humidity control mode based on the RH within the building. The RH of the air within the building may be measured by the thermostat  208  or the IAQ sensor module  304 . There may be times when both the thermostat  208  may request for the blower to operate for cooling/heating while the IAQ control module  404  may also request the blower to operate for IAQ control. This overlap is normal as part of multiple IAQ parameter control. 
     Although not shown in  FIG. 11 , the blower and one or more vent fans (e.g., one or more bathroom fans and/or a range hood fan) may be turned on after the predetermined threshold for PM, VOC, and carbon dioxide has been exceed. The blower and the one or more other vent fans can be turned off after decreasing the PM, VOC, and carbon dioxide to below the same or lower predetermined thresholds or after being on for a predetermined period to avoid excessive overrun. 
       FIG. 12  includes an example table of compressor operation and blower speed for various humidity control modes.  FIG. 13  includes an example method of determining the humidity control mode based on RH within the building and controlling the blower  108  and the compressor  148  based on the humidity control mode. 
     Referring to  FIGS. 12 and 13 , at  1304 , the IAQ control module  404  determines whether a cooling request has been received from the thermostat  208  or the control module  112 . The thermostat  208  generates a cooling request when the temperature measured by the thermostat  208  (or the IAQ sensor module  304 ) is greater than the upper temperature limit of the predetermined temperature range for cooling. As described above, the upper temperature limit may be equal to or based on the setpoint temperature plus a predetermined temperature (e.g., 1, 2, or 3 degrees F.). The lower temperature limit of the predetermined temperature range for cooling may be equal to or based on the setpoint temperature minus the predetermined temperature. After generating the cooling request, the thermostat  208  maintains the cooling request until the temperature becomes less than the lower temperature limit of the predetermined temperature range for cooling. If  1304  is false, at  1308  the IAQ control module  404  sets the humidity control mode to a fifth control mode (Mode 5) and turns the blower  108  off (i.e., discontinues power to the blower  108 ). The blower  108  then slows to a stop. The thermostat  208  (or the IAQ control module  404 ) also turns off the compressor  148  at  1308 . Control returns to  1304  after  1308 . If  1304  is true, control continues with  1312 . 
     At  1312 , the IAQ control module  404  determines whether the RH within the building is greater than a first dehumidification RH setpoint (Predetermined RH1). The first dehumidification RH setpoint is calibratable and may be set, for example, to approximately 50% RH or another suitable value. If  1312  is false, control transfers to  1336 , which is discussed further below. If  1312  is true, the IAQ control module  404  increments a first timer value (Timer 1) by a predetermined increment amount at  1316 , and control continues with  1320 . 
     At  1320 , the IAQ control module  404  determines whether the RH within the building is greater than a second predetermined dehumidification RH. The second predetermined dehumidification RH is calibratable and is greater than the first predetermined dehumidification RH. For example only, the second predetermined dehumidification RH may be approximately 60% RH or another suitable value. If  1320  is false, control transfers to  1328 , which is discussed further below. If  1320  is true, control continues with  1324 . 
     At  1324 , the IAQ control module  404  sets the humidity control mode to a third control mode (Mode 3) and operates the blower  108  at the predetermined low speed (e.g., corresponding to approximately 250 CFM/ton of the condensing unit  164 ). The thermostat  208  (or the IAQ control module  404 ) also operates the compressor  148  at  1324  by applying power to the compressor  148  and the condenser fan  160  via the control module  156  or  276 . Operating the blower  108  at the predetermined low speed while operating the compressor  148  decreases the RH more quickly than operating the blower  108  at a higher speed. Control resets a second timer value (Timer 2) to a predetermined reset value (e.g., zero) at  1334 , and control returns to  1304 . 
     At  1328  (when the RH within the building is not greater than the second predetermined dehumidification RH at  1320 ), the IAQ control module  404  determines whether the first timer value (Timer 1) is greater than a first predetermined value. The first predetermined value corresponds to a first predetermined period. The first predetermined value may be calibrated, for example, to correspond to approximately 10 minutes or another suitable period. If  1328  is true, control transfers to  1324 , as discussed above. If  1328  is false, control continues with  1332 . 
     At  1332 , the IAQ control module  404  sets the humidity control mode to a first control mode (Mode 1) and operates the blower  108  at the predetermined medium speed (e.g., corresponding to approximately 300 CFM/ton of the condensing unit  164 ). The thermostat  208  (or the IAQ control module  404 ) also operates the compressor  148  at  1332  by applying power to the compressor  148  and the condenser fan  160  via the control module  156  or  276 . Operating the blower  108  at the predetermined medium speed while operating the compressor  148  decreases the RH more quickly than operating the blower  108  at a higher speed (e.g., conventional operation) but less quickly than operating the blower at a lower speed (e.g., the first control mode). Control then transfers to  1334 , as discussed above. 
     Referring back to  1336  (when the RH within the building is not greater than the first predetermined dehumidification RH at  1312 ), the IAQ control module  404  resets the first timer value (Timer 1) to the predetermined reset value at  1336 , and control continues with  1340 . At  1340 , the IAQ control module  404  determines whether the RH within the building is less than a third dehumidification RH setpoint (Predetermined RH3). The third dehumidification RH setpoint is calibratable and is less than the first dehumidification RH setpoint. For example, the third dehumidification RH setpoint may be set to approximately 40% RH or another suitable value. If  1340  is false, the IAQ control module  404  sets the humidity control mode to a sixth control mode (conventional operation) and operates the blower  108  at the predetermined high speed (e.g., corresponding to approximately 400 CFM/ton of the condensing unit  164 ). The thermostat  208  (or the IAQ control module  404 ) also operates the compressor  148  at  1344  by applying power to the compressor  148  and the condenser fan  160  via the control module  156  or  276 . Operating the blower  108  at the predetermined high speed while operating the compressor  148  decreases the RH but does so less quickly than operating the blower  108  at a lower speed (e.g., the first control mode or the third control mode). Control then returns to  1304 . If  1340  is true, the IAQ control module  404  increments the second timer value (Timer 2) by the predetermined increment amount at  1348 , and control continues with  1352 . 
     At  1352 , the IAQ control module  404  determines whether the RH within the building is less than a fourth dehumidification RH setpoint. The fourth dehumidification RH setpoint is calibratable and is less than the third dehumidification RH setpoint. For example only, the fourth dehumidification RH setpoint may be approximately 30% RH or another suitable value. If  1352  is false, control transfers to  1360 , which is discussed further below. If  1352  is true, control continues with  1356 . 
     At  1356 , the IAQ control module  404  sets the humidity control mode to a second control mode (Mode 2) and operates the blower  108  at the predetermined medium speed (e.g., corresponding to approximately 300 CFM/ton of the condensing unit  164 ). The thermostat  208  (or the IAQ control module  404 ), however, maintains the compressor  148  off at  1356  and does not apply power to the compressor  148  and the condenser fan  160 . This humidifies the air within the building using condensation on the evaporator  144  and/or in the condensate pan  146 . Control then returns to  1304 . 
     At  1360  (when the RH within the building is not less than the fourth predetermined dehumidification RH at  1356 ), the IAQ control module  404  determines whether the second timer value (Timer 2) is greater than a second predetermined value. The second predetermined value corresponds to a second predetermined period. The second predetermined value may be calibrated, for example, to correspond to approximately 10 minutes or another suitable period. The first and second predetermined values may be the same or different. If  1360  is true, control transfers to  1356 , as discussed above. If  1360  is false, control continues with  1364 . 
     At  1364 , the IAQ control module  404  sets the humidity control mode to a fourth control mode (Mode 4) and operates the blower  108  at the predetermined low speed (e.g., corresponding to approximately 250 CFM/ton of the condensing unit  164 ). The thermostat  208  (or the IAQ control module  404 ), however, maintains the compressor  148  off at  1364  and does not apply power to the compressor  148  and the condenser fan  160 . This humidifies the air within the building using condensation on the evaporator  144  and/or in the condensate pan  146  but humidifies the air less quickly than operating the blower  108  at a higher speed. Control then returns to  1304 . 
       FIG. 14  includes an example table of compressor operation and blower speed for various humidity control modes.  FIG. 15  includes an example method of determining the humidity control mode based on RH within the building and controlling the blower  108  and the compressor  148  based on the humidity control mode that may be performed by the thermostat  208 . 
     Referring to  FIGS. 14 and 15 , at  1504 , the thermostat  208  determines whether the thermostat  208  is set to cooling (not heat or off). If  1504  is false, at  1508  the thermostat  208  sets the humidity control mode to a standby mode (Standby) and turns the blower  108  off (i.e., discontinues power to the blower  108 ). The thermostat  208  also turns off the compressor  148  at  1508 . Control returns to  1504  after  1508 . If  1504  is true, control continues with  1512 . 
     At  1512 , the thermostat  208  determines whether the RH within the building is greater than a first dehumidification RH setpoint (Predetermined RH1). The first dehumidification RH setpoint is calibratable and may be set, for example, to approximately 50% RH or another suitable value. If  1512  is false, control transfers to  1520 , which is discussed further below. If  1512  is true, control continues with  1516 . At  1516 , the thermostat  208  sets the humidity control mode to a first control mode (Mode 1) and operates the blower  108  (e.g., at a predetermined fixed speed). The thermostat  208  also operates the compressor  148  at  1516  by applying power to the compressor  148  and the condenser fan  160  via the control module  156  or  276 . Operating the blower  108  while operating the compressor  148  decreases the RH (i.e., dehumidifies) the air within the building. Control returns to  1504 . 
     At  1520  (when the RH is not greater than the first dehumidification RH setpoint at  1512 ), the thermostat  208  determines whether the RH within the building is less than a second dehumidification RH setpoint. The second dehumidification RH setpoint is calibratable and is less than the first dehumidification RH setpoint. For example, the second dehumidification RH setpoint may be set to approximately 40% RH or another suitable value. If  1520  is false, control returns to  1504  and maintains the states of the blower  108  and the compressor  148 . If  1520  is true, control continues with  1524 . 
     At  1524 , the thermostat  208  sets the humidity control mode to a second control mode (Mode 2) and operates the blower  108  (e.g., at the predetermined fixed speed). The thermostat  208 , however, does not operate the compressor  148  at  1524 . Instead, the thermostat  208  does not apply power to the compressor  148  and the condenser fan  160 . Operating the blower  108  while not operating the compressor  148  increases the RH (i.e., humidifies) the air within the building via condensation on the evaporator  144  and/or in the condensate pan  146 . Control returns to  1504 . 
       FIG. 16  includes a block diagram of an example implementation of a mitigation system using the example of the thermostat  208 . While the example of the thermostat  208  is provided for purposes of discussion, the modules of the thermostat  208  may alternatively be implemented within the IAQ control module  404  or within a combination of the thermostat  208  and the IAQ control module  404 . 
     The thermostat  208  includes a RH sensor  1604  and a temperature sensor  1608 . The temperature sensor  1608  measures a temperature of air at the thermostat  208 . The RH sensor  1604  measures a RH of air at the thermostat  208 . The thermostat  208  may also include a sampling module that samples (analog) measurements of the RH and temperature sensors  1604  and  1608 . The sampling module may also digitize and/or store values of the measurements of the sensors. In various implementations, the RH and temperature sensors  1604  and  1608  may be digital sensors and output digital values corresponding to the respective measured parameters. In such implementations, the sampling module may perform storage or may be omitted. 
     An average module  1612  determines an average RH within the building based on a plurality of RHs measured by the RH sensor  1604  and/or a plurality of RHs measured by the RH sensor  312 . For example, the average module  1612  may set the average RH based on or equal to an average (e.g., non-weighted) of all of the RHs measured by the RH sensor  1604  during a predetermined period before the present time. As another example, the average module  1612  may set the average RH based on or equal to an average (e.g., non-weighted) of all of the RHs measured by the RH sensor  312  during the predetermined period before the present time. As another example, the average module  1612  may set the average RH based on or equal to an average (e.g., non-weighted) of all of the RHs measured by the RH sensor  312  and the RH sensor  1604  during a predetermined period before the present time. The predetermined period may be a predetermined number of samples (e.g., 1-100) or a predetermined period of time (e.g., 1 second to 1 minute). 
     An IAQ score module  1616  determines a present IAQ score for the air within the building based on (all of) the IAQ parameters measured by the IAQ sensor module  304 . As discussed above, the IAQ parameters include RH, temperature, amount of VOCs, amount of carbon dioxide, and amount of particulate. In various implementations, the RH measured by the RH sensor  1604  may be used in place of the RH measured by the RH sensor  312 . Alternatively, an average of the RHs measured by the RH sensors  312  and  1604  may be used. In various implementations, the temperature measured by the temperature sensor  1608  may be used in place of the temperature measured by the temperature sensor  308 . Alternatively, an average of the temperatures measured by the temperature sensors  316  and  1608  may be used. The IAQ score module  1616  determines the IAQ score using one or more lookup tables and/or equations that relate sets of IAQ parameters (RH, temperature, particulate, carbon dioxide, and VOCs) to IAQ scores. 
     For example, the IAQ score module  1616  may set the IAQ score to a value between a predetermined minimum value (e.g., 0) and a predetermined maximum value (e.g., 100), inclusive. The IAQ score module  1616  may decrease the IAQ score toward the predetermined minimum value when one of the IAQ parameters is outside of a respective predetermined range (in the examples of temperature and RH) or is greater than a respective predetermined value (in the examples of carbon dioxide, particulate, and VOCs). A magnitude of the decrease may be based on a magnitude of a deviation of the one of the IAQ parameters outside of the respective predetermined range or above the respective predetermined value. For example, the magnitude of the decrease may increase as the magnitude of the deviation increases and vice versa. 
     The IAQ score module  1616  may increase the IAQ score toward the predetermined maximum value when one of the IAQ parameters transitions from outside of the respective predetermined range or greater than the respective predetermined values to within the respective predetermined range or to less than the respective predetermined value. The IAQ score module  1616  may do the above for each of the IAQ parameters. When all of the IAQ parameters are within the respective predetermined range or less than the respective predetermined value, the IAQ score module  1616  may set the IAQ score toward or to the predetermined maximum value. 
     The IAQ score module  1616  may additionally set the IAQ score based on periods of time that the IAQ parameters have been within the respective predetermined ranges, outside of the respective predetermined ranges, less than the respective predetermined values, or greater than the respective predetermined values. For example, the IAQ score module  1616  may increase the IAQ score toward the predetermined maximum value when the period that one of the IAQ parameters has been within the respective predetermined range increases. The IAQ score module  1616  may decrease the IAQ score toward the predetermined minimum value when the period that the one of the IAQ parameters has been outside of the respective predetermined range increases. The IAQ score module  1616  may increase the IAQ score toward the predetermined maximum value when the period that one of the IAQ parameters has been less than the respective predetermined value increases. The IAQ score module  1616  may decrease the IAQ score toward the predetermined minimum value when the period that the one of the IAQ parameters has been greater than the respective predetermined value increases. The IAQ score module  1616  may do the above for each of the IAQ parameters. 
     A setpoint module  1620  sets the RH setpoint. The RH setpoint may be set to a predetermined value by default. The setpoint module  1620  may set the RH setpoint to a first predetermined RH during heating and may set the RH setpoint to a second predetermined RH that is greater than or equal to the first predetermined RH during cooling. The setpoint module  1620  may adjust the RH setpoint in response to receipt of user input (e.g., to the thermostat  208  or the customer device  524 ). 
     Based on the RH setpoint, a range module  1624  sets a RH range including the humidification RH setpoint and the dehumidification RH setpoint. The dehumidification setpoint is greater than the humidification setpoint. For example, the range module  1624  may set the humidification RH setpoint to the RH setpoint minus a predetermined amount and set the dehumidification RH setpoint to the RH setpoint plus the predetermined amount. The range module  1624  may adjust the predetermined amount in response to receipt of user input (e.g., to the thermostat  208  or the customer device  524 ). Adjustment of the predetermined amount increases or decreases a size of the range defined by the humidification and dehumidification RH setpoints. 
     A humidifier control module  1628  controls operation of the humidifier  432  based on the average RH and the IAQ score. As described above, the humidifier blower  435  may be included with the humidifier  432 . When turning the humidifier  432  on and off (opening and closing the water feed valve  434 , e.g., shown in  FIG. 1 ), the humidifier control module  1628  may additionally turn the humidifier blower  435  on and off. 
       FIG. 17  includes a flowchart depicting an example method of controlling operation of the humidifier  432 . Control may begin with  1704  where the average module  1612  determines the average RH and the IAQ score module  1616  determines the IAQ score, as described above. At  1708 , the humidifier control module  1628  may determine whether the average RH is greater than the RH setpoint. If  1708  is true, control may transfer to  1720 , which is discussed further below. If  1708  is false, control may continue with  1712 . 
     At  1712 , the humidifier control module  1628  may determine whether the circulator blower  108  is ON or whether the air handler unit  136  is in the heating mode. The circulator blower  108  is ON in the heating mode. Thus, the humidifier  432  can humidify the building during operation in the heating mode. If  1712  is true, the humidifier control module  1628  may turn (or maintain) the humidifier  432  on at  1716 , and control may return to  1704 . The humidifier control module  1628  opens the water feed valve  434  of the humidifier  432  to provide water (e.g., to an evaporative pad) for humidification of the air within the building. The humidifier control module  1628  may also turn on the humidifier blower  435  of the humidifier  432 . If  1712  is false, control may transfer to  1724 , which is discussed further below. 
     At  1720 , the humidifier control module  1628  may determine whether the average RH is greater than the dehumidification RH setpoint. If  1720  is true, control may transfer to  1728 . If  1720  is false, control may continue with  1724 . At  1724 , the humidifier control module  1628  may determine whether the average RH is less than the humidification RH setpoint. If  1724  is true, the humidifier control module  1628  may turn (or maintain) the humidifier  432  on at  1716 , and control may return to  1704 . 
     The humidifier control module  1628  may determine whether the supply air temperature is greater than a predetermined temperature at  1728 . Supply air temperature less than the predetermined temperature (e.g., 87 degrees F. or another suitable temperature) may imply that humidification is adding too much moisture and may decrease user comfort. A supply air temperature sensor  1750  (e.g., see  FIG. 1 ) may measure the supply air temperature. The supply air temperature may be the temperature of air output to the building at the air handler unit  136 . The supply air temperature sensor  1750  may be implemented, for example, in ducting that provides supply air to vents of the building or at an outlet of one of the vents. If  1728  is false, control may continue with  1732 . If  1728  is true, control may transfer to  1736 . 
     At  1732 , the humidifier control module  1628  may determine whether the IAQ score is increasing. For example, the humidifier control module  1628  may determine whether the IAQ score (e.g., determined at  1704 ) is greater than a previously determined value of the IAQ score (e.g., from a last instance of  1704 ). If  1732  is true, humidification of the building is contributing to increasing the IAQ score, so the humidifier control module  1628  may turn (or maintain) the humidifier  432  on at  1716 , and control may return to  1704 . If  1732  is false, the humidifier control module  1628  turns (or maintains) the humidifier  432  off at  1736 , and control may return to  1704 . This balances the interest of humidifying the building with the interest of maintaining other ones of the IAQ parameters within their respective predetermined ranges or less than their respective predetermined values. Higher RH can also contribute to higher VOCs and/or carbon dioxide. 
     Referring back to  FIG. 16 , the thermostat  208  may additionally or alternatively (to the average module  1612  and the IAQ score module  1616 ) include a humidity load module  1640 , an on period module  1644 , and a humidification module  1648 . 
     The humidity load module  1640  determines a (predicted) humidity load on the building over the next predetermined period, such as the next day (24 hours) or another suitable future period (e.g., day, 12 hours, etc.). The humidity load corresponds to an amount (e.g., in gallons) of water to be added to the air within the building during the next predetermined period (e.g., day) to achieve the RH setpoint. 
     The humidity load module  1640  determines the (real-time) humidity load based on outdoor ambient temperature (OAT), outdoor RH, indoor ambient temperature (IAT), indoor RH, a predetermined air change per hour of the building, and a predetermined volume of the building. The humidity load module  1640  may determine the humidity load using one or more equations and/or lookup tables that relate OATs, outdoor RHs, IATs, indoor RHs, air changes, and building volumes to humidity loads. For example, the humidity load module  1640  may set the humidity load based on or using the equation: 
     
       
         
           
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                 * 
                 
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                 Conversion 
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                 ⁢ 
                 Value 
               
             
           
         
       
     
     where Load is the humidity load (e.g., in gallons of water per day or per hour), V is the predetermined volume of the building (e.g., in cubic feet), ACH is the predetermined air change per hour of the building, Wi is an indoor moisture content (e.g., in grains/lb of dry air), Wo is outdoor moisture content (e.g., in grains/lb of dry air), and Conversion Value is a predetermined conversion value. The ACH (e.g., in cubic feet of air per hour) may be calibrated and may be, for example, 0.5 for a (air) tightly sealed building, 1.0 for a less (air) tightly sealed building, and 1.5 for a (air) leaky building. For the example of humidity load in gallons per day, the predetermined conversion value may be 33,082. The OAT and the outdoor RH can be measured or obtained, for example, based on the location of the building. The IAT and the indoor RH can be measured by the thermostat  208  and/or the IAQ sensor module  304 . 
     The humidity load module  1640  may determine the indoor moisture content based on the IAT and the indoor RH. The humidity load module  1640  may determine the outdoor moisture content based on the OAT and the outdoor RH. The humidity load module  1640  may determine the indoor moisture content and the outdoor moisture content, for example, using a lookup table or an equation that relates ambient temperatures and RHs to moisture contents. The lookup table or equation may be calibrated based on standard air properties. 
     In various implementations, the humidity load module  1640  may determine the humidity load using the equation above with an average predicted OAT over the next day and an average predicted outdoor RH over the next day. The setpoint temperature and the setpoint RH may also be used. The humidity load module  1640  may determine the average predicted OAT and the average predicted outdoor RH based on weather data for the location of the building, such as from the local data sources  532 . For example, the local data sources  532  may provide predicted OATs and outdoor RHs at the location of the building by hour during the next day. The humidity load module  1640  may average the predicted OATs and average the predicted outdoor RHs to determine the average predicted OAT and the average predicted RH that are used to determine the humidity load for the next day. The humidity load module  1640  may update the humidity load each day for the next day. 
     In various implementations, the humidity load module  1640  may determine the humidity load by determining individual (predicted) humidity loads per hour during the next day and summing individual humidity loads per hour to determine the humidity load during the next day. The humidity load module  1640  may determine the individual humidity loads based on the predicted OATs and outdoor RHs by hour obtained via the weather data for the location of the building, such as from the local data sources  532 . For example, the humidity load module  1640  may determine the individual humidity load for 2-3 pm based on the predicted OAT at 2 pm (or 3 pm) and the predicted outdoor RH at 2 pm (or 3 pm). The humidity load module  1640  may determine the individual humidity loads based on the equation above. In the example of determining individual (hourly) humidity loads, the predetermined conversion value may be 792,968 (33,082*24). 
     As discussed above, the humidifier  432  can be on (and dispensing water for evaporation to humidify the air within the building) or off (and not dispensing water for evaporation). The ON period module  1644  tracks the total amount of time that the humidifier  432  is on during each day. The total amount of time will be referred to as a humidifier ON period (e.g., in hours) of a day. The ON period module  1644  increments the humidifier ON period when the humidifier  432  is on. The ON period module  1644  maintains the humidifier ON period (and does not increment or decrement the humidifier ON period) when the humidifier  432  is off. The ON period module  1644  begins a new humidifier ON period each day. The ON period module  1644  may store one or more previous humidifier ON periods from one or more previous days, such as a last (complete) day. 
     The humidifier  432  has a predetermined evaporation rate of water provided (e.g., in gallons per hour). A predetermined water feed rate of the water feed valve  434  is greater than the predetermined evaporation rate such that the water feed valve  434  provides enough water to the humidifier  432  so the humidifier  432  can achieve the predetermined evaporation rate. 
     The humidification module  1648  determines a predicted humidification (e.g., in gallons of water) that may be provided to the air within the building by the humidifier  432  during the next day based on the predetermined evaporation rate of the humidifier  432  and the humidifier ON period of the last day. The humidification module  1648  may determine the predicted humidification using one of an equation and a lookup table that relates humidifier ON periods and predetermined evaporation rates to humidification values. For example, the humidification module  1648  may set the predicted humidification based on or equal to the predetermined evaporation rate of the humidifier  432  multiplied by the humidifier ON period of the last (previous) day before the present day. 
     The humidifier control module  1628  may compare the humidity load of the next day with the predicted humidification of the next day. If the predicted humidification is less than the humidity load, the humidifier control module  1628  may increase operation of the humidifier  432  before and/or during the next day. For example, the humidifier control module  1628  may turn the humidifier  432  on at times when the circulator blower  108  is on and the humidifier  432  would otherwise be off, such as due to the RH within the building being greater than the humidification RH setpoint. The increased operation of the humidifier  432  may, at least to some extent, offset the predicted humidity load of the next day in an effort to prevent low RH situations from occurring before and during the next day. 
       FIG. 18  includes an example method of controlling operation of the humidifier  432 . Control may begin with  1804  where the humidity load module  1640  determines the humidity load for the next day. As described above, the humidity load module  1640  may determine the humidity load for the next day based on the average predicted OAT for the next day and the average predicted outdoor RH for the next day or the individual predicted OATs and outdoor RHs by hour. 
     At  1808 , the humidification module  1648  determines the predicted humidification for the next day based on the predetermined evaporation rate of the humidifier  432  and the humidifier ON period of the previous (e.g., last) day. At  1816 , the humidifier control module  1628  determines whether the predicted humidification is less than the humidity load. If  1816  is false, the humidifier control module  1628  may maintain the present humidification rate at  1820  and turn the humidifier  432  on, for example, when the RH is less than the humidification RH setpoint or as described in the example of  FIG. 17 . Alternatively, the humidifier control module  1628  may decrease the humidification rate (by turning the humidifier  432  on less frequently and/or for a shorter period while the circulator blower  108  is on) at  1820  before and/or during the next day. For example, the humidifier control module  1628  may leave the humidifier  432  off at times when the circulator blower  108  is on and the humidifier  432  would otherwise be on, such as due to the RH within the building being less than the humidification RH setpoint. This may at least to some extent offset the expected humidity load of the next day in an effort to prevent high RH situations from occurring before and during the next day. 
     If  1816  is true, the humidifier control module  1628  may increase the humidification rate (by turning the humidifier  432  on more frequently and/or for a longer period while the circulator blower  108  is on) at  1824  before and/or during the next day. For example, the humidifier control module  1628  may turn on the humidifier  432  at times when the circulator blower  108  is on and the humidifier  432  would otherwise be off, such as due to the RH within the building being greater than the humidification RH setpoint. This may at least to some extent offset the expected humidity load of the next day in an effort to prevent low RH situations from occurring before and during the next day. 
     The humidifier control module  1628  may also provide various data regarding humidity and humidification to the customer device  524 . For example, the humidifier control module  1628  may provide the IAQ score, humidifier ON period per day, water usage of the humidifier per day (e.g., humidifier ON period multiplied by predetermined feed rate of the water feed valve  434 ), the IAQ score, humidification (e.g., humidifier ON period multiplied by predetermined evaporation rate), humidity load, predicted humidification, and/or other data. As described above, the customer device  524  may display received data on a display. As described above, the customer device  524  may allow a user to adjust RH setpoints and other parameters, for example, to balance IAQ, water, and blower usage. 
     The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.” It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. 
     In this application, including the definitions below, the term module may be replaced with the term circuit. The term module may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC); a digital, analog, or mixed analog/digital discrete circuit; a digital, analog, or mixed analog/digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor (shared, dedicated, or group) that executes code; memory (shared, dedicated, or group) that stores code executed by a processor; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-chip. 
     The term code, as used above, may include software, firmware, and/or microcode, and may refer to programs, routines, functions, classes, and/or objects. The term shared processor encompasses a single processor that executes some or all code from multiple modules. The term group processor encompasses a processor that, in combination with additional processors, executes some or all code from one or more modules. The term shared memory encompasses a single memory that stores some or all code from multiple modules. The term group memory encompasses a memory that, in combination with additional memories, stores some or all code from one or more modules. The term memory may be a subset of the term computer-readable medium. The term computer-readable medium does not encompass transitory electrical and electromagnetic signals propagating through a medium, and may therefore be considered tangible and non-transitory. Non-limiting examples of a non-transitory tangible computer readable medium include nonvolatile memory, volatile memory, magnetic storage, and optical storage. 
     The apparatuses and methods described in this application may be partially or fully implemented by one or more computer programs executed by one or more processors. The computer programs include processor-executable instructions that are stored on at least one non-transitory tangible computer readable medium. The computer programs may also include and/or rely on stored data.