Methods and systems for optimized hvac operation

Abstract

Heating, cooling, and ventilation equipment in a building may be controlled to improve building performance and/or occupant comfort. For a building, such as a low-load building, with multiple sub-systems of an overall HVAC system that can be actuated to impact indoor environmental conditions, an operational mode used to control such HVAC equipment may be selected. The selection may be based on input data from sensors, including indoor and outdoor environmental conditions, and occupancy level in combination with multiple models. Data collected over time may be used to form multiple types of models, including predictive models of building performance, future indoor conditions, and occupancy levels, and/or energy usage. The models may be used to select a control strategy. Based on the selected strategy and user preferences, a set of rules may be applied to generate control signals that control operation of HVAC subsystems.

What is claimed is: 
     
         1 . A system for controlling indoor environmental conditions of a building, the system comprising:
 at least one processor configured to:
 store at least one user preference; 
 acquire indoor environmental conditions from sensor data; 
 acquire an occupancy level; 
 acquire outdoor environmental conditions; 
 predict future building conditions based on the indoor environmental conditions, the occupancy level, the at least one user preference, and the outdoor environmental conditions; 
 select at least one control output based on the future building conditions; and 
 transmit a control signal based on the at least one control output to at least one of heating equipment, cooling equipment, and ventilation equipment. 
   
     
     
         2 . The system of  claim 1 , wherein at least one of the acquired indoor environmental conditions, outdoor environmental conditions, and occupancy levels comprises historical data values. 
     
     
         3 . The system of  claim 1 , the at least one processor is further configured to:
 acquire an energy metric from at least one energy meter;   detect at least one of heating, cooling, and ventilation equipment requires service based on the energy metric; and   transmit a message signal to a user interface.   
     
     
         4 . The system of  claim 3 , wherein the user interface is operated by a service provider. 
     
     
         5 . The system of  claim 1 , wherein the occupancy level is acquired from a location signal transmitted by a portable electronic device. 
     
     
         6 . The system of  claim 5 , wherein the occupancy level is based on the location signal indicating within a proximity of the at least one processor. 
     
     
         7 . The system of  claim 1 , wherein:
 the processor is further configured to execute at least one predictive model; and   the at least one predictive model is an occupancy predictive model and determines an occupancy level for a future time point, the occupancy level indicating a likelihood of presence or activity of occupants in the building.   
     
     
         8 . The system of  claim 1 , wherein:
 the at least one processor is further configured to execute at least one predictive model and acquire energy consumption data values; and   the at least one predictive model is an energy consumption model and determines energy consumption levels for at least one of the heating equipment, cooling equipment, and ventilation equipment.   
     
     
         9 . The system of  claim 8 , wherein the at least one processor is further configured to transmit a notification when a current energy consumption data value differs from a predicted energy consumption value by more than a threshold amount, the notification recommending maintenance on at least one of the heating equipment, the cooling equipment, and the ventilation equipment. 
     
     
         10 . The system of  claim 1 , wherein the at least one processor is further configured to:
 simulate at least one scenario based on a building performance model and control inputs for at least one of the heating equipment, the cooling equipment, and the ventilation equipment   select a scenario based on selection criteria;   determine a target state based on the selected scenario and the occupancy level; and   select at least one control output based on the target state.   
     
     
         11 . The system of  claim 10 , wherein the building performance model is based on historical data having at least one of indoor environmental conditions, outdoor environmental conditions, occupancy levels, and energy consumption values for previous time points. 
     
     
         12 . The system of  claim 11 , wherein the building performance model determines a rate of change of indoor conditions in response to at least one of outdoor conditions and energy consumption. 
     
     
         13 . The system of  claim 1 , wherein the indoor environmental conditions are at least one of temperature values, humidity values, and indoor air quality values. 
     
     
         14 . The system of  claim 1 , wherein the at least one processor is further configured to:
 transmit a notification to a portable electronic device, the notification having a recommendation to a user for improving building performance.   
     
     
         15 . The system of  claim 1 , wherein the at least one control signal is to increase ventilation by controlling a fan based on a high occupancy level. 
     
     
         16 . A method of operating equipment to control indoor environmental conditions of a building, the method comprising:
 acquiring at least one current indoor state from at least one indoor sensor;   predicting a future occupancy level based on occupancy data;   setting, selectively based on the predicted future occupancy level, a target state based on user preferences;   setting, selectively based on the predicted future occupancy level, the target state based on at least one of a duration of time to reach user preferences and a minimization of at least one energy metric; and   controlling at least one of heating equipment, cooling equipment, and ventilation equipment based on the target state and the at least one current indoor state.   
     
     
         17 . The method of  claim 16 , the method further comprising:
 acquiring energy usage data from at least one energy meter;   monitoring performance information of at least one of heating equipment, cooling equipment, and ventilation equipment;   transmit energy usage data and performance information to at least one processor;   
     
     
         18 . The method of  claim 17 , the method further comprising:
 determining energy efficiency data based on the energy usage data and the performance information; and   sending a user alert signal when energy efficiency data is below a threshold value.   
     
     
         19 . The method of  claim 16 , wherein the occupancy data is derived from a signal transmitted by a portable electronic device. 
     
     
         20 . The method of  claim 16 , wherein:
 the at least one sensor is a plurality of sensors; and   a plurality of sensors are located within at least one zone of the building or at least one sensor is in more than one zone.   
     
     
         21 . The method of  claim 16 , wherein the target state is at least one of a temperature value and humidity value. 
     
     
         22 . The method of  claim 21 , wherein the target state is temporarily set to a different value based on a user defined range of values and a time period when the target state is allowed to be changed. 
     
     
         23 . The method of  claim 16 , wherein controlling the cooling equipment includes setting a target state to pre-cool or pre-heat the building to a certain temperature value. 
     
     
         24 . At least one non-transitory, tangible computer readable storage medium having computer-executable instructions, that when executed by a processor, perform a method of operating equipment, the method comprising:
 acquiring at least one current indoor state from at least one indoor sensor;   predicting a future occupancy level based on measured occupancy data;   receiving input indicating a user preference;   setting a target state based on the user preference by:
 when the user preference is a first preference, selecting the target state such that the user preference can be reached within a duration of time; and 
 when the user preference is a second preference, selecting the target state based on at least one energy metric; and 
   controlling at least one of heating, cooling, and ventilation equipment based on the target state and the at least one current indoor state.   
     
     
         25 . The at least one non-transitory, tangible computer readable storage medium of  claim 24 , wherein controlling at least one of heating, cooling, and ventilation equipment comprises:
 generating control signals to a ventilation subsystem and generating control signals to a heating or cooling subsystem.   
     
     
         26 . A system for controlling indoor environmental conditions of a building by generating control signals to a plurality of subsystems of an HVAC system, the system comprising:
 at least one processor configured to:
 receive user input indicating a user preferred environmental condition; 
 acquire sensor data; 
 for each of a plurality of scenarios for controlling the plurality of subsystems:
 simulate control of the HVAC system in accordance with the strategy and the acquired sensor data; 
 compare a simulated result of control according to the scenario to a criteria relating to building operation; and 
 based on the comparison and a comparison made for at least one other scenario of the plurality of scenarios, determine whether to apply the control scenario; and 
 
 generate to control values to the subsystems of the HVAC system in accordance with a control scenario determined to be applied. 
   
     
     
         27 . The system of  claim 26 , wherein the at least one processor is further configured to:
 detect at least one of heating, cooling, and ventilation equipment requires service based on comparing a simulated result of control according to the scenario to a criteria relating to building operation; and   transmit a message signal to a user interface recommending maintenance on at least one subsystem of the HVAC system.