LV-11-017 -- Applications of a Simplified Model Calibration Procedure for Commonly Used HVAC Systems ✓ Most Recent

A calibration procedure for simplified building energy simulation models for commonly used HVAC systems has been developed through an ASHRAE-sponsored project (ASHRAE RP-1092). The procedure is applied to five buildings. These five buildings include a 44-story office building, a low-rise office building, a church, a university teaching building, and a university research building. Three of the five buildings are located in Omaha, Nebraska (cold climate). Two buildings are located in College Station, Texas (hot and humid climate). This paper presents the calibration procedure and summary results of five case studies. A two-level calibration procedure provides a good approach for model calibration. The case studies strongly indicate that the simplified model calibration procedure developed can be used to accurately calculate long-term energy consumption data using short-term field energy measurement data for different types of buildings with different systems. The first-level calibration procedure is very important and improves the model accuracy significantly. The average absolute value of NMBE decreased from 41% to 6%, and CV(RMSE) decreased from 63% to 26% for these building models after the first-level calibration. The second-level calibration procedure further reduced these values to 2.5% and 22.4%, respectively. After calibration of the simulation using four weeks or less of measured hourly data, the average of the absolute values of the prediction error for annual consumption values was 2.5%, with a maximum error of 9% for the case studies examined. General information on the building and HVAC systems are the most critical input parameters for the simplified model calibration. Short-term hourly chilled-water consumption and hot-water consumption are the most critical energy data for calibration.