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Modern Energy LLC

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Ronald F. Amberger PE
John DeFrees PE
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John A. DeFrees PE

Principal Engineer

Specialties include energy data analysis, energy utility analysis, project management and customer relations.

Professional Experience:

  • Founding Principal of Modern Energy, LLC.
  • Former Partner and Founding Principal of CDH Energy Corporation.
  • Management responsibility for divisional engineering office.
  • 27 years experience with commercial, industrial and residential energy systems.
  • Principal investigator on numerous technical and research projects.
  • Experienced with various industrial and commercial refrigeration technologies utilizing mechanical vapor compression and absorption technologies.
  • Participated in monitoring projects involving residential and commercial HVAC systems, commercial lighting, industrial refrigeration and applications involving steam boilers.
  • Designed and built test facility dedicated to utility steam condenser research projects.
  • Experienced with computer modeling and analysis techniques.
  • Eight years experience as adjunct faculty teaching heat transfer and thermofluid science at college level.

Employment History:

  • Founding Principal, Modern Energy, LLC.
  • Senior Energy Engineer, LaBella Associates, PC.
  • Founding Principal, CDH Energy Corporation, Cazenovia, New York.
  • Division Manager, The Fleming Group, East Syracuse, New York.
  • Senior Engineer, RIT Research Corporation, Rochester, New York.


  • Bachelor of Science, Mechanical Engineering, Rochester Institute of Technology, 1981


  • American Society of Heating, Refrigerating, and Air Conditioning Engineers
  • Association of Energy Engineers
  • Licensed Professional Engineer, State of New York


First Place, 1993 ASHRAE Technology Award, Category IV - Industrial Facilities or Processes, Honeywell Farms, Inc., Jamaica, New York.


  • DeFrees, J.A., R. Stuckey, ‘Demonstration of a Condensing Economizer,’ Energy Engineering, Volume105, Number 5, 2008
  • DeFrees, J.A., R. Stuckey, J. Foote, ‘Condensing Economizers,’ ASHRAE Journal, November 2007.
  • DeFrees, J.A., R. Stuckey, ‘Demonstration of a Condensing Economizer,’ World Energy Engineering Congress, August 2007.
  • DeFrees, J.A., A. Dickerson, ‘Traditional and Non-traditional Application of Condensing Boiler Economizers,’ American Council for Energy Efficient Economy, July 2005.
  • DeFrees, J.A., “Case Studies Synthesizing the Elements of Preferred Design,” Northeast Combined Heat and Power Application Center, June 2004
  • Amberger, R.F., J.A. DeFrees, ‘Retrofit Cogeneration System Increases Refrigeration Capacity,’ American Society of Heating, Refrigeration and Air Conditioning Engineers Journal, March 1993.
  • Amberger, R.F., J.A. DeFrees, E. Wichert, ‘Analysis of Engine Powered Refrigeration with Heat Recovery in Industrial Refrigeration Plants,’ International Institute of Ammonia Refrigeration, 1991 Annual Meeting, SanFrancisco, CA, March 1991.
  • DeFrees, J.A., R. O’Neil, ‘ Monitoring and Analysis of a Pulse Combustion Steam Boiler,’ 1992 International Gas Research Conference, Orlando, Florida, November 1992.
  • DeFrees, J.A., R. Drake, W. Tomala, E. Wichert, ‘Measurement and Evaluation of a Subcooling Engine-Driven Refrigeration System,’ 1992 International Gas Research Conference, Orlando Florida, November 1992.
  • Amberger, R.F., J.A. DeFrees, ‘Cascade Refrigeration Utilizing Waste Heat,’ 1988 Cogeneration Congress, Atlantic City, June 15-16, 1988.
  • Amberger, R.F., J.A. DeFrees, ‘Infiltration Analysis of a Residential High Rise Building,’ IAQ 87, Washington DC, May 18-20, 1987.
  • Amberger, R.F., J.A. DeFrees, R.M. Desmond, ‘Augmented Heat Transfer Rates in Steam Condensers,’ 9th World Energy Engineering Congress, Atlanta, Georgia, October 22-24, 1986.