The Air-Conditioning and Refrigeration Technology Institute (ARTI) is focused on the future with itsHVAC&R Research for the 21st Century(21-CR) program. This private-public sector collaboration has the mission of identifying and undertaking precompetitive research to decrease energy consumption and increase indoor environmental quality (IEQ).

The 21-CR program is pursuing research projects that will provide both innovations and incremental improvements.

The goal is to overcome technological barriers that prevent the commercialization of next-generation systems.

Alternative Equipment

This research area involves investigation of hvacr cycles other than fluorocarbon vapor compression cycles. Selected projects include:

  • The Efficiency of Water Vapor Compressors Suitable for Air-Conditioning Applications — Phase I. Develop general design concepts and efficiency limits for water-vapor compressors.

  • Evaluation of the Performance Potential of CO2 as a Refrigerant in Air-to-Air Air Conditioners and Heat Pumps: System Modeling and Analysis. Study the potential of CO2 as a refrigerant.

High-Efficiency Equipment

This area looks at improved heat exchangers, motors, compressors, etc. Some projects are:

  • High Performance Heat Exchangers for Air Conditioning and Refrigeration Applications — Phase I. Evaluate serpentine fins used with flat tubes in a fluid-to-air heat exchanger.

  • Refrigerant Evaporation Characteristics Inside Flat Passages. Evaluate refrigerant evaporation heat transfer and pressure drop characteristics inside flat passages.

System Integration

This encompasses improved distribution systems, waste heat recovery, advanced controllers, etc. A sample project is:

  • Energy Savings Potential of Flexible and Adaptive HVAC Distribution Systems for Office Buildings — Phase I. Document recent developments, and the barriers and opportunities for development of these systems.

Indoor Environmental Quality

This area incorporates enhan-ced control of temperature, moisture, indoor contaminants, ventilation, etc. Projects underway include:

  • Investigation of the Causes of “Black Soot Phenomena.” Inves-tigate reports of deposition of “black soot” occurring in residential and commercial buildings.

  • Defining the Effectiveness of UV Lamps Installed in Circulating Air Ductwork. Identify the key factors and validate the impact of these factors on the effectiveness of UV light in ductwork.

Environmentally Friendly Working Fluids

This covers refrigerants, lubricants, secondary heat transfer fluids, etc. A typical project is:

  • Assessing the Commercial Implications for ASHRAE A3 Flam-mable Refrigerants Used in Air Conditioning and Refrigeration Systems. Report on the current state of knowledge on flammable refrigerants in North America, including a regulatory assessment.

Additional information on the 21-CR program is available online at