New Study on Geothermal Heat Pumps vs. Variable Refrigerant Flow Heating and Cooling

Discussion in 'General Discussions' started by GEO, Jan 8, 2015.

  1. GEO

    GEO Member Staff Member Forum Leader

    Definitive scientific research has shown that a geothermal heat pump (GHP) system offers far more efficiency in a large commercial building than a variable refrigerant flow (VRF) system.

    In January 2013, the Geothermal Exchange Organization (GEO)—with financial assistance from Southern Company—contracted a research team from Oklahoma State University and Oak Ridge National Laboratory to evaluate the relative performance of GHP vs. VRF heating and cooling systems installed at the American Society of Heating Refrigeration and Air-conditioning Engineers (ASHRAE) International Head-quarters Building in Atlanta, GA.*

    When ASHRAE contracted a major renovation of their two-story, 31,000 sq. ft. building in 2008, they established a “living lab” to offer the chance to evaluate commercial building energy and sustainability performance. In addition to improvements to its envelope, floor plan and sustainability features such as lighting, the building uses three separate heating, ventilation and air-conditioning (HVAC) systems:
    • A variable refrigerant flow system for spaces on the first floor;
    • A geothermal heat pump system, primarily for spaces on the second floor; and,
    • A dedicated outdoor air system (DOAS), which supplies fresh air to both floors.
    The GEO research team studied the relative performance of the GHP and VRF systems, determining energy consumption of each, and heating and cooling required by the building. “There’s no question about it—GHPs trump VRF systems for efficiency and cost savings,” said GEO President and CEO Doug Dougherty. “Our study of heating and cooling performance at the ASHRAE Building proves that over a two-year period—when all variables were accounted for—energy use by the geothermal system averaged 44% less than the VRF system.”

    Read the complete article

    Download the complete study: Performance of the HVAC Systems at the ASHRAE Headquarters Building
  2. GEO

    GEO Member Staff Member Forum Leader

    GEO Webinar
    Geothermal Heat Pumps vs.
    Variable Refrigerant Flow Systems

    A recent peer-reviewed scientific study of heating and cooling technologies has shown that a geothermal heat pump (GHP) system offers 44% greater efficiency than a variable refrigerant flow (VRF) system in a large commercial building.

    JOIN the Geothermal Exchange Organization (GEO) for a FREE Webinar on Wednesday, February 4, from 10:00 to 11:30 am (U.S. Central Time), which will describe this cutting-edge efficiency comparison of GHP vs. VRF heating and cooling systems at the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) Headquarters Building in Atlanta, GA.

    Moderated by GEO President and CEO Doug Dougherty, the webinar will feature a PowerPoint presentation and discussion by Principal Investigator, Dr. Jeff Spitler, Oklahoma State University Regents Professor of Mechanical Engineering and his research team from OSU and Oak Ridge National Laboratory.

    Who Should Attend? Everyone who tunes in to the GEO webinar will gain valuable insights into geothermal vs. VRF heating and cooling systems efficiency and how the GEO study arrived at its results. The webinar will be particularly interesting and useful to those involved in the design, engineering, acquisition, sales and installation of HVAC and geothermal heat pump systems, including:

    Architects • Builders • Utilities
    HVAC Engineers and Designers • HVAC Contractors
    Geothermal System Designers • Geothermal Equipment Providers
    Geothermal Sales Personnel​

    Learn More about Energy Efficiency Offered by Geothermal vs. VRF
    on Wednesday, February 4, from 10:00 to 11:30 a.m. (Central Time)

    Click Here for FREE Registration

  3. GEO

    GEO Member Staff Member Forum Leader

  4. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Some day one has money other days one has time. I ran out of both.

    Sorry I missed it.

    Remember when all the folks thought being a Geo-junkie was nuts?

    I get rack refrigeration, but am not sure about VRF yet.

    I was late to the party on EDM seals and stab fit fittings. But the force was with me. I will do the work to look at the links.

    Thank you,

  5. Karl McGaugh

    Karl McGaugh New Member

    This was an impressive study. ASHRAE bit the hand of Daikin VRF in the results. Geothermal is absolutely the winner for energy efficiency, and green sustainable construction.
    VRF is all hat and no horse. I will never look at VRF for anything new.
    I will also never look at a water source heat pump system that is not closed loop geothermal.
    The other aspect that was not discussed is the long term cost of ownership. GEO wins without any subsidies and with HDPE pipe warranties of 50 years the cost of the wells should be financed by The Electric Utility paying for all well field costs.
  6. James Myers

    James Myers New Member

    Nice study! This study will be helpful.
  7. FelipeDoyle

    FelipeDoyle Banned

    This study is really helpful.
  8. pole7

    pole7 New Member

    I wanted to know what you guys thought of the VRF manufacturer's reply to this study? They seem to bring up some valid points about the vast difference in building loads between the 1st and 2nd floors and how the the systems are used differently. Here is the video of their presentation. The main points are shown between minutes 1:30 and 5:30. Most of the remaining video is marking point for or against GHP and VRF.

  9. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    Pole7 in other venues the pros have discussed the validity of the research and the fact is one can read it however they want. A study often reflects the opinion of the studier.
    It is my feeling that first, it is not apples to apples and second both industries ignore obvious flaws in their own arguments.
    The VRV guys like their splits best and espouse the efficiency of ductless systems yet they use ducts and often ducted units to solve problems that one outlet can cause. They also ignore the obvious point that anything ducted has efficiency penalties, so a ductless geo for instance could be more efficient than a ductless air-source and a ductless furnace could be more efficient than a ducted one etc.

    Geo advocates suggest that air source is fundementally inefficient which is not true but much like geo, design/application often tanks efficiency.
    Geo is much more expensive and cost v benefit can not be ignored for the average consumer. In that context even at 30% or 50% less efficiency, air source might be a better fit for some applications.

    I have used both in one home without embarassment or inner conflict. Ducted house: geo. Slab addition with open floor plan: mini split. Cost v benefit in that case: home run.

    It is also worth mentioning the age of the equipment in that study means the technology is obselete. We might also note that minimum operating temps are dropping quickly for VRVs and will expand their reach North.
    Palace GeoThermal likes this.

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