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Daikin AC Provides Clarifications to Geothermal System Comprisons


CARROLLTON, TX – Daikin AC recently made available a technical article clarifying marketing information circulated by other manufacturers, comparing the performance of geothermal water source heat pump systems and air-cooled variable refrigerant volume heat pump systems installed at the updated ASHRAE National Headquarters in Atlanta, Georgia.

Several attempts to compare system energy efficiencies have been made public. However, the comparisons have been expressed only in energy consumed, without consideration of the load characteristics (usage, solar load, ventilation, etc.) between the areas served. As a result, Daikin believes the published “efficiency numbers” are of little real value, and the messaging potentially misleading.

As stated in the article,This is essentially the same as stating which car is most fuel efficient, only looking at input (gallons) without relating input to output (miles per gallon). A true measurement of efficiency/performance must include the ratio between input and output”. The report also points out that ASHRAE has a disclaimer on their website in response to this issue, in part which states “…To fully evaluate the performance of these systems, additional data will be required to account for the difference in loads on the various systems. The areas served by each system as well as the envelope, occupant and ventilation loads differ.” 

The report is available at http://www.daikinac.com/content/resources/white-papers-and-guides/