Energy Manager

Chiller efficiency boosted 20% under proposed Standard 90.1 addendum

January 7, 2013 - Chiller efficiencies for air and water cooled chillers would be boosted to more than 20% under a proposed addendum to the ASHRAE/IES energy standard.

January 7, 2013  By  Alyssa Dalton

Proposed addendum ch to ANSI/ASHRAE/IES Standard 90.1-2010, Energy Standard for Buildings Except Low-Rise Residential Buildings, changes the requirements for air and water cooled chillers as defined in section and the efficiency requirements listed in table 6.8.1C. This change is a continuation of the efficiency improvements that were implemented in 2010 by further improving the efficiency requirements, according to Dick Lord, a member of the committee who developed the proposal through a working team of the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) chiller section.

Addendum ch is open for public review until January 14, 2013. For more information, visit

In 2010, a Path B was added to the standard for part load intensive water cooled chillers. Proposed addendum ch would expand Path B by adding requirements to include air cooled chillers. Also as part of this change, efforts were made to bring the efficiency requirements for water cooled positive displacement and centrifugal chillers together while considering the available technology, and to chillers to be applied at other application conditions where one technology may better suited than the other. If approved, the new efficiency requirements would go into effect on Jan. 1, 2015.

According to ASHRAE, the proposed efficiency requirements in addendum ch increase annual energy savings to 23.1% vs. Standard 90.1-2004 and 8.3% vs. Standard 90.1-2010. In 2010, the overall weighted average savings resulted in a 16.2% improvement in chiller annualized energy use vs. Standard 90.1-2004, it added.


Also open for public comment until January 14, 2013, is addendum aq that makes minor changes to improve clarity and to address issues identified in sections and

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