Ongoing commissioning for commercial buildings

Project Leader

• R. Zmeureanu

Description

The monitoring of energy performance of an existing building is essential for the optimization of information extracted through the analysis of monitored data can reveal the effects of real operating conditions and performance of HVAC systems and subsystems, on the energy performance, particularly degradation over time. The improvement of energy performance can also be estimated if appropriate calculation methods are applied. Improved methods should be developed for analysis of performance, and integrated in building energy management systems. 

The terms commissioning, re-commissioning, retro-commissioning, continuous commissioning and ongoing commissioning are often used to describe the actions undertaken to verify compliance of building components and systems with the design specifications and the operator’s current goals. For new buildings, commissioning normally takes place before occupancy, and ensures the mechanical systems are checked for performance and system effectiveness at part-load and design conditions. For existing facilities, re-commissioning (retro-commissioning) is used to ensure the facility performance meets initial design specifications. The new concept of ongoing commissioning has been proposed for existing buildings to ensure that the strategies implemented continue to meet the increasingly stringent targets that are expected to evolve in the future. The objective is to attain optimum operation by performing 1) ongoing monitoring of the systems, 2) data analysis and 3) sensor recalibration, and 4) systems maintenance as identified by performance assessment procedures. This process has yet to be automated. Only basic steps have been taken in developing methods to automatically assess and maintain the performance of the mechanical systems. 

This project will build on the following: Annex 40 of the IEA, ‘‘Commissioning of Building HVAC systems for Improved Energy Performance”, International Performance Measurement and Verification Protocol (IPMV 2007), (ASHRAE, 2005, 2007a, 2008), and the ASHRAE Building EQ Labelling approach (Jarnagin, 2009) as well as on the results from three decades of related research projects and engineering applications (Haberl & Claridge, 1987; Haberl et al., 1996; Liu et al., 2002; Liu et al., 2003; Larsen et al., 2008; Ginestet & Marchio, 2010). The objective is the development of an integrated approach for assessing the as-operated energy performance of commercial/institutional buildings, and the identification of measures for improvement of performance as opposed to general benchmarking. The approach integrates the following three components: 

1. The ongoing commissioning of energy systems through the collection and analysis of monitored data to assess the as-operated energy performance of major HVAC equipment as well as the whole building energy performance. The development of benchmarking data from past monitored data, for use as reference data for comparison with data from the ongoing commissioning; 

2. The development of a new method for the calibration of building energy analysis models using monitored data (from the ongoing commissioning) and short-term measurements. 

3. The use of calibrated simulation models to estimate the as-designed energy performance and potential improvements in energy performance.

Sub-Projects

• 4.2a  Development of new analysis techniques of building energy performance and of benchmarking models based on monitored data
• 4.2b  Development of new methodologies for calibrated simulation models

Back to Theme IV : Smart Building Operating Strategies