System and method for characterization of retrofit opportunities in building using data from interval meters

Inventors

Zeifman, Michael • Lazrak, Amine

Assignees

Fraunhofer USA Inc

Abstract

Systems and methods for characterization of retrofit opportunities are described. The methods may comprise computing, using at least one computing device disposed remote from a building and based at least in part on heating, ventilation and air conditioning (HVAC) runtime data associated with the building, one or more thermal characteristics of the building. In some embodiments, a model-predicted indoor temperature may be fitted against thermal data measured by a thermostat at the building. The thermal characteristic of the building may comprise a thermal insulation, an air leakage rate and/or an HVAC efficiency. The method may be used to determine, using the at least one computing device, suitability of the building for a retrofit opportunity to improve energy efficiency of the building. Determining the suitability may comprise evaluating the one or more thermal characteristics. The HVAC runtime data may be computed based on data received from a thermostat or a meter, such as an electric or a gas meter.

Core Innovation

The invention relates to a remote, computing-device-based method for auditing a building by using electronic resource consumption information from an electronic resource consumption meter disposed remote from the building. The method records an actual resource consumption profile and constrains resource consumption information when data points fluctuate more than a threshold by varying a time period for at least two data points so that the constrained resource consumption information corresponds to the actual resource consumption profile. Heating, ventilation and air conditioning (HVAC) runtime data associated with the building is then computed based on the constrained resource consumption information.

The method executes a computer model to compute confidence intervals for one or more thermal characteristics of the building, where the thermal characteristic comprises at least one selected from thermal insulation, an air leakage rate, and HVAC efficiency. The confidence intervals are computed by performing a correlation of a solution of the computer model that computes a value indicative of a temperature of one or more walls of the building over time, and the confidence intervals are used to constrain a search space for possible values of the one or more thermal characteristics.

Using the constrained one or more thermal characteristics, the method calculates a calculated energy efficiency of the building and executes a simulation model to simulate one or more retrofit opportunity scenarios to determine suitability of the building for a retrofit opportunity to improve energy efficiency. For each scenario, a simulated energy efficiency of the building is calculated and compared with the calculated energy efficiency, and an electronic notification is transmitted comprising at least one recommendation corresponding to at least one simulated retrofit opportunity selected from upgrade of building thermal insulation, sealing of air leaks, and replacement of HVAC equipment.

Claims Coverage

Two independent claims are identified. Each claim includes remote receipt and constraining of fluctuating meter data to compute HVAC runtime data, followed by computing confidence intervals for thermal characteristics and using those intervals to constrain a search space, then calculating energy efficiency, simulating retrofit opportunity scenarios for suitability, and transmitting an electronic recommendation notification.

The independent claim set covers a workflow that constrains fluctuating meter-derived information to match an actual consumption profile, computes HVAC runtime data, uses a computer-model solution correlated to wall temperature over time to compute confidence intervals for thermal characteristics, constrains a search space based on those confidence intervals, calculates energy efficiency, simulates retrofit opportunity scenarios for suitability, and transmits electronic recommendations for retrofit actions.

Stated Advantages

Documented Applications