The U.S Green Building Council was founded in 1993.  Thereafter the USGBC developed a standardized rating system for new construction that rewarded a project in eight sustainability categories for excellence in design and life cycle performance.  Each energy conserving or environmental quality included helped the applicant earn “credits.”  An increasing scale of total credits earned is used to identify graduated levels of achievement. 

Acceptance of the LEED Green Building Rating System has grown significantly over the past 10 years, including growth in membership, the number of rating systems available for occupied spaces (from New Construction to Core and Shell), to the services offered.  The USGBC currently counts 41 governments with LEED requirements and another 12 considering adding them.

The Council can now boast that: (1) all new GSA, DOS, EPA and most new military construction projects will require LEED certification to a minimum level, (2) at least 13 state governments offer incentives and/or passed requirements that involve LEED certification for public building projects, (including: CA, CT, ID, MA, MI, MD, ME, NJ, NY, OR, PA, UT, WA), and (3) Numerous cities now require some form of LEED certification or provide incentives for sustainability in new construction projects, both public and/or private. (To name a few of the more significant ones: Atlanta, Boston, New York City, Chicago, Boulder, Calgary, Vancouver, Austin, Dallas, Houston, Washington DC, Kansas City, Omaha, Phoenix, Scottsdale, Portland, Seattle, Los Angeles, Long Beach, San Francisco, San Jose, Santa Monica, and San Diego).  A complete list of the jurisdictions that require some form of LEED compliance is available from the USGBC or the author, upon request.

A draft of version 2.2 of the LEED - New Construction (NC) rating system has just been posted for public comment.  The comment period ends February 1st.  It is anticipated that there will be a second public review this spring, with membership balloting expected in the summer of 2005.  A complete copy of the draft (with or without the original text) can be downloaded from the USGBC web site. 
(http://www.usgbc.org/News/usgbcnews_details.asp?ID=1156)  I encourage everyone to review it and register your comments about the document.

You will find at least six of the proposed rating system credits and four prerequisite requirements are directly impacted or made easier to obtain, when using airflow measurement inputs to maintain and verify intake rates, for pressurization control and for commissioning.  These six credits are equally divided between the sections “Energy & Atmosphere” and “Indoor Environmental Quality”.  The “Existing Building” rating system (LEED-EB) already contains most of these new provisions and was approved by the council earlier this year.

The single most important credit for maintenance of minimum ventilation rates is EQc1 “Outdoor Air Delivery Monitoring.”  This credit will require that Outdoor Air be monitored continuously, that the minimum rates required by ASHRAE 62.1-2004 be maintained and that the BAS will provide an alarm (visible or audible to the occupants) when the intake rate falls more than 15% below the ASHRAE requirement, regardless of the method of measurement or control technology employed.

The revised LEED-NC 2.2 credit language also places significant restrictions on the use of CO2-based-Demand Controlled Ventilation and CO2 sensor usage:

• use only in densely occupied spaces (>24 persons/1000 SF), have at least one sensor per space, otherwise must monitor outside airflow rate directly,

• sensors must be located in breathing zone (not returns), as defined by ASHRAE 62.1

• certified by manufacturer, maximum sensor error 75 ppm and require calibration no more than once every five years

• if used for DCV – must comply with 62.1, and provide a means to satisfy the new area-based ventilation rate component.

The Draft also proposes that outdoor CO2 concentrations may be “assumed” at 400 ppm and not measured.  However, an incorrect assumption may lead to significantly large errors in the calculation of occupancy or air intake rate per person (as we have attempted to demonstrate in calculations and modeling contained in prior articles.)

Regardless of your predisposition on the subject of “Green” buildings, the LEED Rating system has the support of many local jurisdictions, state governments and federal agencies.  It will not be going away anytime soon.  So, unless we ignore the public sector of our controls markets, everyone should become familiar with the requirements of the LEED systems.

The USGBC has recently reached out to trade and professional organizations, the one most significant to us being ASHRAE.  Simultaneously, ASHRAE has taken a number of steps to better understand the movement and provide their membership with information required to make day-to-day design decisions in light of these environmental and conservation objectives. 

Within this context, I would like to invite anyone interested in participating in a newly formed ASHRAE Technical subcommittee on Optimized Control Strategies for Green Buildings, to contact me directly (by phone 843-756-1828 or email: Damiano@EBTRON.com).

The subcommittee is being developed under ASHRAE Technical Committee 1.4 “Control Theory and Applications” and will meet for the first time during the ASHRAE Winter Meeting on Sunday afternoon February 6, between 3 – 4 PM at Lake Buena Vista’s Wyndham Palace Resort.  We will use this meeting to establish the level of industry-wide interest, recruit members, begin to outline industry needs and committee objectives.  Membership in ASHRAE’s TC1.4 is not necessary to participate in the subcommittee, but “corresponding” membership is helpful for both the committee leadership and the members in order to keep track of activities and each other.

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