The question, addressed by this project, is how to cost effectively save space conditioning energy and dollars in buildings with ducted constant air supply systems, particularly since many of these older central city buildings are 50% or less occupied. The problem for these older systems is how to design a low cost VAV system.
CBEI researchers worked with a local HVAC contractor to test a unique approach to this problem and determine the energy performance of a potential low cost option.
CBEI research has demonstrated through simulation that, for selected building types over a range of climate zones, HVAC package solutions exist that have the potential to provide at least 50% HVAC energy savings with a simple payback of 4 years or less.
This report is the pdf version of the CBEI Final report and results.
A fault detection and diagnostics system for rooftop air conditioners was developed using low-cost electronics. The system was designed to be compatible with the VOLTTRONTM platform. The underlying fault detection and diagnostics methodology utilizes virtual sensors to measure parts of the equipment operation that are sensitive to common faults. Using virtual sensors reduces costs while also providing accurate and reliable diagnostics.
This project implemented, validated and documented an automated system for training virtual refrigerant charge sensors for rooftop unit ACs. The system automatically tunes empirical parameters of a virtual sensor for estimating the amount of refrigerant in a system. The engineering time and costs associated with calibrating a virtual sensor are reduced because of the automated testing in an open laboratory and the reduced number of tests.
In 2015-16 United Technologies Research Center (UTRC), in collaboration with the CBEI, developed OpenStudio measures for seven systems/components used in HVAC retrofit packages identified with high energy saving potentials in BP4 for small office, medium office, stand-alone retail, and primary school buildings in certain climate zones.
This research investigates opportunities for improving building performance and occupant satisfaction through an iterative process of empirical fieldwork in green buildings and computer simulation modeling. This project demonstrates that the simulation-modeling framework is feasible and useful. Additionally, this project has generated a variety of important empirical insights about how the usability of building-level green features and social and organizational factors affect occupant and operator behavior.
A practical control algorithm for coordinating bot AC and refrigeration equipment was developed and evaluated using an energy simulation testbed for a convenience store. It was validated using actual convenience store data. The simulations allowed evaluations of savings for the unit coordinator compared to conventional control over a cooling season. The controller was designed to minimize implementation costs in that it does not require additional sensors and is self-learning.
Field demonstrations provided test and evaluation data for virtual sensor based AFDD concepts and provided a laboratory demonstration on the VOLTTRON platform.
HVAC package solutions were identified that met the stated objectives, based on 6 building types (quick service restaurant, full service restaurant, small hotel. large hotel, supermarket, and convenience store) in 6 region/climate zone combinations.
This report presents an overview of the development of the Energy Audit Tool along with case study results from the analysis of 40 buildings, and nine audited buildings at the Philadelphia Navy Yard.
A scalable low-cost optimal chiller plant control algorithm was developed and effectively demonstrated with 128 case studies covering a variety of chiller plant load variations with each case being a weekly simulation of whole-building dynamic HVAC system models with closed loop local controls and supervisory chiller plant controls. Model-in-the-loop (MiL) analysis suggests a promising average energy saving of ~15% for medium office buildings and an average energy saving of ~10% for large hotel buildings.
This project developed and demonstrated novel techniques for cost-effective AFDD for Air Handling Units for small/medium commercial buildings. The diagnostic accuracy is over 95% and the payback period is less than two years.
A BIM Planning Guide for Retrofit Projects was developed that enables design teams to quickly plan the use of energy and other model adoption process early in a project.
The goal of this project was to demonstrate and evaluate a practical business case for implementation of the RTU Coordinator across multiple locations. This report provides a summary of the PnP algorithm, a description of the savings estimates for previous PnP evaluations, a description of site selection processes and savings results for the BoA sites, and a description of the final demonstration sites, implementations and preliminary results.