LEED-Certification Appeal
I read with great interest the Liability & Litigation column by Gina Vitiello, LEED AP, on the appeal of the LEED certification awarded to Northland Pines High School in Eagle River, Wis., in the August issue of HPAC Engineering ("Appeal Raises Questions About LEED Certification"). Unfortunately, these kinds of problems were inevitable from the get-go. I believe this column will be a wake-up call for architects and engineers.

I have been concerned about liabilities arising from green design guidelines for about a year now. In June, I gave a presentation at NeoCon in Chicago. One of the points I raised concerned legal liabilities and the U.S. Green Building Council's (USGBC's) refusal to accept any responsibility for the "advice" about guideline compliance it gives to architects during the design process.

This issue, as the column stated, will not go away; it will be amplifying in the future. Engineers and architects should be aware of the potential dangers they face by blindly following green design guidelines. Insurance agencies already are well aware of them.
Stephen J. Vamosi, PE
Intertech Design Services Inc.
Cincinnati, Ohio

The USGBC seems to prey on undereducated, underinformed owners and the public. Now LEED seems to have wormed its way into contract documents. Some now even require that a certain level of certification be achieved. This is very common with federal projects. Maybe LEED should include statements that the certification system shall not be used to contractually bind architects, engineers, and contractors to meet any level of certification. Liability and responsibility should be synonymous. If LEED has no legal liability, why should it be given any responsibility in making sure a contract is green?
MikeH
excerpted from HPAC.com

I knew this was coming. I watch them put "frosting" on buildings to gain LEED points regardless of its actual value to the building. The worst part is that most of these are public buildings, and our tax dollars are going to waste. The principles of green construction are good; certification brings out all of the fancy language, worthless additions, etc.
Rjb67zl
from HPAC.com

LEED is a standard of relative greenness, not a contract document for overpaid lawyers and underemployed engineers to litigate. Before LEED, there was little awareness of green design principles, much less an understanding of related issues.

While I have my own gripes with the LEED scoring and certification system, the LEED process has been a powerful force in bringing green design mainstream. Just the fact designs can be 40 to 60 percent more efficient with little or no increase in first cost is testament to the opportunity for the United States to become more competitive and less dependent on fossil fuels.
Ronald Perkins
Supersymmetry USA Inc.
Navasota, Texas

There long has been plenty of awareness of energy-efficient, sustainable design, and it was implemented to the extent clients were willing to invest in the future value of their projects. What we lacked was a bureaucratic entity to take credit for it. Now that we have one, it should be consistent and objective, or it will not be sustainable itself.
Nyse Guy
from HPAC.com

Thank you for printing the column on the appeal of the LEED certification awarded to Northland Pines High School. It reinforces my concerns about LEED.

In Cincinnati, The Herald Building received LEED certification despite the removal of a dozen houses and associated mature trees. I am not saying this was a bad redevelopment project. I just do not understand how removing trees and using new materials to construct an office building in a city with a surplus of office space meets the USGBC's implied intent to preserve the environment.
Jim Drye, PE
Cincinnati, Ohio

Fan Selection
I found the article "Fan Selection and Energy Savings"  very useful.

I come from an industrial environment. We have many HVAC units on the roof. The fan blows into a discharge plenum. From the plenum, three or four ducts go in many different directions. According to the article, the plenum should be two-and-a-half times the diameter of the duct from the discharge of the fan. I have seen different sizes of plenums, but haven’t seen any article or best practices concerning plenum design and how to tie discharge ductwork from a fan into a plenum for the best efficiency. Can the author help?
Bill Thaman
Milford Center, Ohio

Author's response:
The article gives a recommendation for the length of straight duct required at the discharge of a fan to achieve a uniform velocity profile of fluid before any free discharge or elbow. This will eliminate system effect at such a transition.

I understand space often is a luxury not present in HVAC designs. For such instances, AMCA Publication 201-02, Fans and Systems, provides excellent guidelines. Page 26 of the publication gives a graph used to calculate a system-effect factor to account for various installations. This factor can be added to static pressure during design of a system.

Later sections of the publication give charts for various installations that need to be used in conjunction with the graph on Page 26. Pages 30 and 31 give charts for finding the correct system-effect curve, depending on the amount of ductwork between a fan and a free discharge or, in your application, plenum.

AMCA Publication 201-02 gives a recommendation for straight ductwork. A built-in transition will alleviate some of the system effect associated with the rapid expansion of air at a free discharge.
Brian Mleziva
Greenheck Fan Corp.
Schofield, Wis.