ASHRAE Insights

1049-RP, Building System Design Synthesis and Optimization

An ASHRAE study developed a model-based design optimization process to help reduce the capital cost and energy use of buildings. This design process can be used to evaluate design options including choices of system components, physical connections between components, and the size and operation of the components. This approach was evaluated on two example design briefs and shown to identify novel HVAC system configurations and an energy reduction up to 15% lower compared to an existing benchmark system design. The report presents a new metric for evaluating ‘effectiveness’ of a system in operating with the minimum possible energy used.

Three technical papers were submitted for presentation in future editions of the ASHRAE HVAC&R Research.

1049-RP was sponsored by TC 4.7, Energy Calculations. The principal investigator was Victor Hanby of Loughborough University.

1051-RP, Procedures for Reconciling Computer-Calculated Results with Measured Energy Data

Calibration simulation is the process of using an existing building simulation program and ‘tuning’ the various inputs so that the predictions match closely with observed energy use. Despite wide interest in this area, this calibration process has had to rely on user knowledge, past experience, statistical expertise, engineering judgment, and trial and error. This research developed a systematic calibration methodology to perform this reconciliation. A general methodology, consisting of four aspects, is proposed in the final report. Researchers deem this method to be robust, rational, efficient, and flexible enough to satisfy different user preferences. The final report illustrates the methodology with three case studies.

Two technical papers were published in the ASHRAE HVAC&R Research (Vol. 12(1), Jan. 2006 & Vol. 13(2), Mar. 2007).

1051-RP was sponsored by TC 4.7, Energy Calculations. The principal investigator was Dr. Agami Reddy of Drexel University.

1169-RP, Field Testing of Building Envelope Heat Recovery during Infiltration/Exfiltration

Past studies have found thermal coupling between conduction and infiltration/exfiltration airflow to be significant in building envelopes under controllable condition. On average 20% –40% infiltration/exfiltration heat recovery has been reported. However, field testing does not exist for buildings where both infiltration and exfiltration can occur simultaneously. This research develops a method to measure the energy impact of this simultaneous infiltration and exfiltration in residential buildings.   The research set out to develop information suitable for inclusion in the ASHRAE Handbook, Fundamentals volume, including a test method, infiltration heat recovery (IHR) data, and an analytic procedure to characterize IHR.

Technical papers (Vol. 112(2), QC-06-056-Pt. 1 & QC-06-056-Pt. 2) on this project were presented at the 2006 Annual Meeting and are now available.

1169-RP was sponsored by TC 4.3, Ventilation Requirements and Infiltration. The principal investigator was Mark Ackerman of the University of Alberta.

1173-RP, Improvement and Validation
Of Unitary Air Conditioner and Heat Pump Simulation Models at Off-Design Conditions

Current simulation tools for unitary air conditioners and heat pumps are limited in providing accurate predictions at some off-design conditions. This research project focuses on improved modeling methods for these part load conditions. Specific accomplishments detailed in the final report include identification of improved modeling methods for two phase refrigerant entering compressor, effects of non-uniform distribution of refrigerant flow and airflow, and improved tuning methods for charge modeling.

A technical paper on this project was published in the ASHRAE HVAC&R Research (Vol. 12(3), July 2007).

1173-RP, was sponsored by TC 8.11, Unitary and Room Air Conditioners and Heat Pumps. The principal investigator was Dr. Eckhard Groll of Purdue University.

1189-RP, Investigation of Mechanism and Operating Environments that Impact the Filtration Efficiency of Charged Air Filtration Media

Electrically charged filter materials are more common than ever in air cleaning applications. However, studies have shown that standard air filter tests do not reveal all phenomena that can take place when charged air filters are exposed to various contaminants. This research project helps designers better understand the performance of these charged air filtration media. The project studies behavior of various charged filter materials, performs lab and field testing, and characterizes factors such as operating conditions, particle size, and resistivity on filter efficiency degradation and pressure drop.

1189-RP was sponsored by TC 2.4, Particulate Air Contaminants and Particulate Air Contaminant Removal Equipment. The principal investigator was Matti Lehtimaki of VTT Automation.

1194-RP, Dynamic Modeling
Of Chilled Water Cooling Coils

This research developed a fully validated transient chilled water cooling coil model. It is believed to be the first fully validated by experimental data.   These computationally efficient models are valuable tools for developers and can help speed development of system control and fault detection and diagnostic (FDD) algorithms.

Four technical papers were submitted for future publication in the ASHRAE HVAC&R Research and future ASHRAE meetings.

1194-RP was sponsored by TC 7.4, Building Operation Dynamics. The principal investigator was Dr. James Braun of Purdue University.

1240-RP, Field Method-of-Test
For Identification and Quantification
Of Organic Acids on Desiccants so as to Determine Refrigeration Systems Chemical Condition

Quality manufactured hermetic systems are those free of processing debris and water contaminants. Desiccants work to trap moisture and any formed organic acids. This research developed a procedure to analyze desiccants from small to large hermetic systems to identify system dryness, system thermal response and lubricant life. This, coupled with existing standard measurements, provide the engineer with a more complete history of machine life.

A technical paper (Vol. 112(1), CH-06-14-2) on this project was presented at the 2006 Winter Meeting and are now available.

1240-RP was sponsored by TC 3.3, Refrigerant Contaminant Control. The principal investigator was Dr. Richard Cavestri of Imagination Resources.

The final reports for these projects are available for free for ASHRAE members. Members can log onto ASHRAE.org and go to the Research link under the Technology tab. ASHRAE Transactions papers are available for $5 for ASHRAE members at www.ashrae.org/bookstore.