HVAC controller with integrated airside and waterside cost optimization

1. A heating, ventilating, or air conditioning (HVAC) system for a building, the HVAC system comprising:

a waterside system comprising waterside HVAC equipment that consumes one or more consumable resources from utility providers to generate a heated and/or chilled fluid;

an airside system comprising airside HVAC equipment that receives the heated and/or chilled fluid from the waterside system and uses the heated and/or chilled fluid to heat and/or cool a supply airflow provided to the building; and

a HVAC controller that receives inputs from both the waterside system and the airside system and performs an airside/waterside optimization process to determine control outputs, wherein the control outputs operate the waterside HVAC equipment and the airside HVAC equipment, wherein the airside/waterside optimization process comprises:

obtaining a function that calculates a predicted cost of the one or more consumable resources consumed by the waterside system and by the airside system; and

performing an integrated process that minimizes the predicted cost of the one or more consumable resources consumed by the waterside system and by the airside system over a plurality of discrete time steps subject to a set of constraints comprising temperature constraints for the building, the integrated process determining both an amount of thermal energy resources required by the building to satisfy the temperature constraints and control outputs for the waterside system that produce the amount of thermal energy resources required by the building based on the inputs from the waterside system and the airside system.

2. The HVAC system of claim 1 , wherein the function that calculates the predicted cost accounts for at least one of an amount of the one or more consumable resources consumed by the waterside system or the airside system and a monetary cost of purchasing the one or more consumable resources from the utility providers.

3. A predictive cost optimization system for a building HVAC system that uses both a waterside system and an airside system to heat and/or cool a supply airflow provided to a building, the predictive cost optimization system comprising:

a HVAC controller comprising a processor and memory that receives inputs from both the waterside system and the airside system and performs an airside/waterside optimization process to determine control outputs, wherein the control outputs operate the waterside system and the airside system, wherein the airside/waterside optimization process comprises:

obtaining a function that calculates a predicted cost of one or more consumable resources consumed by the waterside system and by the airside system;

performing an integrated process that minimizes the predicted cost of the one or more consumable resources consumed by the waterside system and by the airside system over a plurality of discrete time steps subject to a set of constraints comprising temperature constraints for the building, the integrated process determining both an amount of thermal energy resources required by the building to satisfy the temperature constraints and control outputs for the waterside system that produce the amount of thermal energy resources required by the building based on the inputs from the waterside system and the airside system.

4. The predictive cost optimization system of claim 3 , wherein:

the set of constraints comprises a temperature evolution model for the building; and

the temperature evolution model predicts a temperature of the building as a function of one or more thermal energy resources provided to the building by the waterside system.

5. The predictive cost optimization system of claim 3 , wherein performing the integrated process comprises determining an amount of the one or more consumable resources that must be purchased from utility providers to allow the waterside system to produce the amount of thermal energy resources required by the building.

6. The predictive cost optimization system of claim 5 , wherein determining the amount of the one or more consumable resources that must be purchased from the utility providers to allow the waterside system to produce the amount of thermal energy resources required by the building comprises:

accessing a performance curve for waterside HVAC equipment of the waterside system, wherein the performance curve defines relationship between a thermal energy resource produced by the waterside HVAC equipment and one or more consumable resources that must be consumed by the waterside HVAC equipment to produce the thermal energy resource.

7. The predictive cost optimization system of claim 6 , wherein:

the performance curve is at least three-dimensional and defines an amount of the thermal energy resource produced by the waterside HVAC equipment as a function of at least two input variables for each device of the waterside HVAC equipment at each time; and

performing the integrated process comprises independently adjusting the at least two input variables for each device of the waterside HVAC equipment at each time.

8. The predictive cost optimization system of claim 6 , wherein the HVAC controller is configured to generate the performance curve by converting a non-convex performance curve into a convex performance curve comprising a plurality of piecewise linear segments.

9. The predictive cost optimization system of claim 3 , wherein:

the integrated process uses linear programming and linearized performance curves for waterside HVAC equipment of the waterside system to adjust the control outputs over the plurality of discrete time steps; and

the airside/waterside optimization process comprises adjusting for inaccuracies in the linearized performance curves using nonlinear programming and nonlinear performance curves for the waterside HVAC equipment.

10. The predictive cost optimization system of claim 3 , wherein the function that calculates the predicted cost accounts for at least one of an amount of the one or more consumable resources consumed by the waterside system or the airside system and a monetary cost of purchasing the one or more consumable resources.

11. A heating, ventilating, or air conditioning (HVAC) system for a building, the HVAC system comprising:

a waterside system comprising waterside HVAC equipment that consumes one or more consumable resources from utility providers to generate a heated and/or chilled fluid;

an airside system comprising airside HVAC equipment that receives the heated and/or chilled fluid from the waterside system and uses the heated and/or chilled fluid to heat and/or cool a supply airflow provided to the building; and

a HVAC controller that receives inputs from both the waterside system and the airside system and performs an airside/waterside optimization process to determine control outputs, wherein the control outputs operate the waterside HVAC equipment and the airside HVAC equipment, wherein the airside/waterside optimization process comprises:

performing an integrated process that selects control outputs that correspond to a minimum predicted cost of the one or more consumable resources consumed by the waterside system and by the airside system over a plurality of discrete time steps subject to a set of constraints comprising temperature constraints for the building, the integrated process determining both an amount of thermal energy resources required by the building to satisfy the temperature constraints and control outputs for the waterside system that produce the amount of thermal energy resources required by the building based on the inputs from the waterside system and the airside system.

12. The HVAC system of claim 11 , wherein:

the set of constraints comprises a temperature evolution model for the building; and

the temperature evolution model predicts a temperature of the building as a function of one or more thermal energy resources provided to the building by the waterside system.

13. The HVAC system of claim 11 , wherein performing the airside/waterside optimization process comprises determining an amount of the one or more consumable resources that must be purchased from the utility providers to allow the waterside system to produce the amount of thermal energy resources required by the building.

14. The HVAC system of claim 13 , wherein determining the amount of the one or more consumable resources that must be purchased from the utility providers to allow the waterside system to produce the amount of thermal energy resources required by the building comprises:

accessing a performance curve for the waterside HVAC equipment, wherein the performance curve defines a relationship between a thermal energy resource produced by the waterside HVAC equipment and one or more consumable resources that must be consumed by the waterside HVAC equipment to produce the thermal energy resource.

15. The HVAC system of claim 14 , wherein:

the performance curve is at least three-dimensional and defines an amount of the thermal energy resource produced by the waterside HVAC equipment as a function of at least two input variables for each device of the waterside HVAC equipment; and

performing the integrated process comprises independently adjusting the at least two input variables for each device of the waterside HVAC equipment.

16. The HVAC system of claim 14 , wherein:

the waterside HVAC equipment comprises a chiller; and

the performance curve defines an amount of the thermal energy resource produced by the chiller as a function of both a load on the chiller and a temperature of the chilled fluid produced by the chiller.

17. The HVAC system of claim 14 , wherein the HVAC controller is configured to generate the performance curve by converting a non-convex performance curve into a convex performance curve comprising a plurality of piecewise linear segments.

18. The HVAC system of claim 11 , wherein:

the integrated process uses linear programming and linearized performance curves for the waterside HVAC equipment to adjust the control outputs over the plurality of discrete time steps; and

the airside/waterside optimization process also comprises adjusting for inaccuracies in the linearized performance curves using nonlinear programming and nonlinear performance curves for the waterside HVAC equipment.

19. The HVAC system of claim 11 , wherein the waterside system comprises thermal energy storage configured to store a thermal energy resource produced by the waterside HVAC equipment for subsequent use.

20. The HVAC system of claim 11 , wherein the predicted cost of the one or more consumable resources comprises at least one of an amount of the one or more consumable resources consumed by the waterside system or the airside system and a monetary cost of purchasing the one or more consumable resources from the utility providers.