ASHRAE Journal - February 2010 - 10

Comfort and Performance The discussion of ASHRAE’s building energy labeling program in the December 2009 issue does not address how the label correlates level of comfort with a building’s energy performance. During the Energy Crisis of 1974, all sorts of skull-duggery was used to reduce energy consumption, including the misguided removal of lamps from lighting fixtures (without disconnecting ballasts), closing outdoor air dampers and adjusting thermostats to uncomfortable and unproductive levels of control. Buildings that earn an A+ energy label, while subjecting occupants to miserable service, ultimately get the rating they deserve from the market. The idea resembles the Danish Energy Agency’s regulated scoring system for buildings as described to participants in the University of Washington’s IDL Study Tour of Energy Efficient Scandinavian Hospitals in June 2009. (http://idlseattle.com/Resources/HD_Tours_2009info. html) A key element of the Danish program is a uniform (and user friendly) rating tool that scores each building on a common platform based on its inherent qualities of design and installation. However, challenges of administering the program could overwhelm local governments, leading to a lack of enforcement, low confidence in the credential and high levels of non-participation or misleading scores. For the label to mean anything, it needs to be correlated with the quality of service provided. If comfort was not a concern, ASHRAE would likely not exist and the accounting office of Scrooge and Marley from Dickens’s A Christmas Carol would earn an “A” for belowmarket levels of coal and lamp oil use. Jim Moler, P.E., Member ASHRAE, Brentwood, Tenn. the 1970s in the U.S. as a response to the energy crisis. The EBTRs and other strategies conceived in that timeframe led to the “freezing in the dark” syndrome for describing energy conservation. Not only did the committee consider the maintenance of comfort essential for receiving a Building EQ label, but they also felt that onsite verification by a professional was an absolute necessity. This requirement was strongly emphasized by our colleagues from CIBSE in the U.K. based on their experiences with building energy labeling. Mr. Moler may wish to review the ASHRAE Building Energy Labeling Program Report of June 2009 to note the references and requirements for maintenance of comfort and onsite verification contained in Appendix A. This report, along with other information on the Building EQ program may be found online at www.buildingeq.com. We would like to thank Mr. Moler for emphasizing this very important point. Ronald E. Jarnagin, P.E., Fellow ASHRAE, Richland, Wash. Re: A Closer Look at Chiller Ratings I have questions about the article “A Closer Look at Chiller Ratings” by W. Ryan Geister and Mike Thompson. I tried to follow the authors’ logic for the weightings assigned in Table 1 of the article and had questions regarding Figure 6. It was stated that it is important to understand this figure as a demonstration of the tool. Looking at Figure 6, it appears that points that are either above 75% load or above 75°F ECWT (not just points that satisfy both conditions) are lumped in the 100% load, 85°F ECWT bucket. So, from Figure 6, an operating point of 80% load and 70°F ECWT or a point of 45% load and 80°F ECWT is put in the bucket of 100% load and 85°F ECWT. Is this correct? The descriptive paragraph states “that this typical application demonstrates 54% of operation with warmer than 75°F condenser water with loads greater than 75% load.” Should this say “with warmer than 75°F condenser water or with loads greater than 75% load”? Also, do the authors have any feel for how many twochiller plants are sized at 100% of the system load vs. 125% or 150%? William Dietrich, Member ASHRAE, Catonsville, Md. Author Responds The authors strongly agree with Mr. Moler that favorable ratings should not be allowed if human comfort is compromised. This issue was discussed early on in the project committee that developed the program. The general feeling was that the ratings would only have meaning provided that comfort was maintained. We are all too aware of the effect of the Emergency Building Temperature Regulations (EBTR) that were imposed in 10 ASHRAE Journal Authors Respond Thank you, Mr. Dietrich, for pointing this out. It is correct to state that the condition does not always meet both the condenser water temperature above 75°F (24°C) and load points above 75%, but it is more accurately stated “with ashrae.org February 2010

ASHRAE Journal - February 2010

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