HVAC Breaking News

Oct. 25, 2007: Chiller Proposal Represents Energy Savings for Standard 90.1

October 25, 2007
/ Print / Reprints /
/ Text Size+

ATLANTA - According to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), an estimated annual energy savings of 13 percent relative to ASHRAE/IESNA Standard 90.1-2004 should result from a proposed addendum regarding air- and water-cooled chillers.

ANSI/ASHRAE/IESNA Standard 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings, provides minimum requirements for the energy-efficient design of buildings except low-rise residential buildings. Fourteen proposed addenda to the 2007 standard, due out for publication later this year, currently are open for public comment.

Among the addenda is proposed addendum m, which establishes effective Jan. 1, 2010, an additional path of compliance for water-cooled chillers as well as consolidation and new requirements for some of the existing categories. The proposed addendum was developed by a team of Standard 90.1 members, industry manufacturers, and energy advocacy groups, including the American Council for an Energy-Efficient Economy (ACEEE) and the Air-Conditioning and Refrigeration Institute (ARI), and was supported by ARI chiller manufacturers.

Product development for water-cooled chillers in recent years has focused on improving off-design and part-load performance where most of the operating hours occur, according to Drake Erbe, chair of the standard’s mechanical subcommittee. Variable speed drive (VSD) technology has advanced and is finding widespread application in water-cooled chillers. The use of VSDs has led to off-design and part load improvement of the chiller’s performance with efficiencies of up to 30 percent in integrated part-load value (IPLV).

Under the proposed addendum, an alternative set of efficiency levels, Path B, is established for water-cooled chillers intended for applications where significant time is expected at part load. All Path B chillers must be equipped with demand limiting controls. Under this proposal, compliance with Standard 90.1 can be achieved by either meeting the requirements of Path B or Path A (intended for applications where significant operating time is expected at full load conditions). However, both full-load and IPLV levels must be met to fulfill the requirements of Paths A or B, according to Erbe.

The proposed addendum also combines water-cooled positive displacement chillers into one category and adds a new size category for centrifugal chillers at or above 600 tons. The air-cooled chiller without condenser equipment type category has been eliminated. All air-cooled chillers without condensers must now be rated with matching condensers.

The minimum efficiencies of air-cooled chillers have also been updated, Erbe said. Efficiencies in the inch-pound version of Standard 90.1 are now expressed in energy efficiency ratio (EER) for air-cooled chillers, kW/ton for water-cooled chillers, and coefficient of performance (COP) for absorption chillers to reflect industry practices. Tables 6.8.1 H through J listing minimum full load and non-standard part load value (NPLV) efficiencies of water-cooled centrifugal chillers at non-standard rating conditions have been eliminated and replaced by an algebraic equation. The tables will now be included in the User’s Manual.

This proposal is estimated to save 457.6 GWh of energy per year compared to the requirements of the 2004 version of Standard 90.1. This represents an annual chiller energy savings of 13.3 percent, according to Erbe.

Proposed addendum m to ASHRAE/IESNA Standard 90.1 is available during its public review period, which ends Oct. 29. To read the addendum or to comment, visit www.ashrae.org/publicreviews.

Publication date: 10/22/2007

Did you enjoy this article? Click here to subscribe to The NEWS Magazine

You must login or register in order to post a comment.



Image Galleries

2014 MCAA Annual Convention

Scenes from the 2014 MCAA Annual Convention in Scottsdale, Ariz.


NEWSmakers: Julian Scadden

Training is an ongoing process. Julian will discuss how you can generate maximum return on time and energy invested training by following a three part process. Listen to this podcast to get expert tips on training, tracking and follow up. 

More Podcasts



NEWS 04-14-14 cover

2014 April 14

Check out the weekly edition of The NEWS today!

Table Of Contents Subscribe


Which statement on service calls best applies to your business?
View Results Poll Archive


2014 National Plumbing & HVAC Estimator

Every plumbing and HVAC estimator can use the cost estimates in this practical manual!

More Products

Clear Seas Research


Clear Seas ResearchWith access to over one million professionals and more than 60 industry-specific publications, Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.


Magazine image
Register today for complete access to ACHRNews.com. Get full access to the latest features, Extra Edition, and more.


facebook icontwitter iconyoutube iconLinkedIn i con