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              Email:    Dr. Stanley A. Mumma,
   Ph.D., P.E



   Since February 15, 2001

Potential LEED Green Building Rating Points?

Executive Summary

The DOAS approach, as advocated at this web site, has the potential to generate up to 21 Green Building Rating points, up to 80% of the minimum points needed for Certification.

This section of the web site is intended to explore the potential rating points that the DOAS/radiant mechanical system design could contribute to the overall Green Building rating. This is significant for its energy and environmental impacts, and presently additional public money is available to encourage better design.

The Green Building Rating Standard
The Leadership in Energy and Environmental Design (LEED) Green Building Rating System (https://www.usgbc.org/ShowFile.aspx?DocumentID=1095), version 2.2 was promulgated to improve the environmental and economic performance of new and existing commercial, institutional, and high-rise residential buildings.

The rating system consists of the following 6 major categories, and maximum points:
    Sustainable Sites:                           14
    Water Efficiency:                             05
    Energy and Atmosphere:                  17
    Materials and Resources:                 13
    Indoor Environmental Quality:            15
    LEED Innovation Credits:                  05
    Total Maximum Possible Points:    69

Certification Levels:
    LEED Certified:                                     26-32 points or >37% of max.
    LEED Certified Silver Level:                    33-38 points or >47% of max.
    LEED Certified Gold Level:                     39-51 points or >56% of max.
    LEED Certified Platinum Level:               52-69 points or >75% of max.

Assessment of the DOAS Rating Point Potential against the LEED Std.
The DOAS/Radiant mechanical system has the potential to generate rating points in 5 of the major categories: i.e. Water Efficiency, Energy and Atmosphere, Materials and Resources, Indoor Environmental Quality, and LEED Innovation Credits. Each specific building project will require it's own analysis, however in general the following rating points should be realized with the DOAS approach.

Water Efficiency: (DOAS Potential 1 point in some geographic locations)
    Water Credit 3: Water Use Reduction of 20% 1 point, or 30% 2 points. Since the DOAS approach
      uses an enthalpy wheel to humidify the building during the winter, a significant reduction in
      municipal water supply is realized.

Energy and Atmosphere: (DOAS Potential 4 points)
    Energy credit 1: Optimize Energy Performance (HVAC, Bldg. envelope, Illumination, etc.), 2-10
      points. The DOAS approach reduces both the energy use and demand of the mechanical
      equipment and hence of the building. As a result there is about a 25% reduction in the mechanical
      system operating costs. This alone is close to enough to generate 2 points in new construction
      and 2-4 points in existing buildings.
    Energy credit 4: Elimination of HCFC's. This is accomplished by selecting new chiller equipment
      that does not use HCFC's. This generates 1 rating point.
    Energy credit 5: Measurement and verification. The required DOAS automation system will
      accomplish this objective. This generates an additional rating point.

Materials and Resources: (DOAS Potential 4 points)
    Material credit 3: Resource Reuse. The radiant system components can be reused without any
      additional treatment for reuse. This generates up to 2 rating points.
    Material credit 4: Recycled Content. The radiant system can be made from post-consumer or
      post-industrial recycled materials, i.e. aluminum, or copper. This can raise the percentage of
      recycled building material content. This generates up to 2 rating points.

Indoor Environmental Quality: (DOAS Potential 8 points)
    IEQ credit 1: Carbon Dioxide Monitoring with a maximum CO2 differential between the space and
      OA of 530 PPM. This is a standard part of the DOAS automation and control system. This
      generates 1 rating point.
    IEQ credit 2: Increase Ventilation Effectiveness. The DOAS approach accomplishes this by first
      placing the correct OA flow rate to each conditioned space (something all air VAV systems can
      not assure) and second by the use of high aspiration diffusers. This generates 1 rating point.
    IEQ credit 3: Construction IAQ Management Plan, to prevent absorptive materials from moisture
      damage during construction and to provide a two week purge with 100% OA prior to occupancy.
      The ability of the DOAS to decouple the space sensible and latent loads permits the first objective
      to be met. And the fact that the DOAS uses only 100% OA makes the 2nd objective easy to
      meet. This generates 2 rating points.
    IEQ credit 6: Controllability of Systems. One point is for perimeter spaces control, including
      illumination; and one point is for space by space illumination and temperature controls. This
      generates 2 rating points.
    IEQ credit 7: Thermal Comfort. The DOAS system hits a home run in this area by decoupling the
      space sensible and latent loads. As a result it is easy and energy efficient to maintain the
      operators humidity and temperature desires. This generates 2 rating points.

LEED Innovation Credits: (DOAS Potential 4 points)
    Functional integration of the fire suppression and thermal transport systems is a big resource
      conserving innovation
    The DOAS concept is an innovative solution to a very long-standing problem in our industry, i.e.
      proper delivery of ventilation air.
    Radiant cooling integrated with the DOAS system capable of decoupling the
      space sensible and latent loads provides innovative solutions to:
            excessive thermal transport energy use,
            improved thermal comfort, and
            large resource conservation by greatly reducing the building plenum depth (and associated
               materials for the structure, enclosure, partitions, vertical human transportation equipment,
               and vertical piping and ductwork).

Please visit the Papers section of this site for more information on
      Dedicated Outdoor Air Systems and Radiant Ceiling Panels.

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Copyright 2001 Bob Hedman.