Wednesday, August 13, 2014

Changes in LEED v4 that Affect Air Distribution

Last fall at the Greenbuild show in Philadelphia, the USGBC rolled out the latest version of the LEED rating system, called LEED v4. There are some significant changes in LEED v4 from the credit categories to the specific credits themselves.

First, the credit categories were changed a little. Two new categories were created: Integrative Process and Location & Transportation. Many of the Location & Transportation credits came from the Sustainable Sites section of the previous version of LEED. The Water Efficiency section did not change much, but did get a couple new credits and prerequisites.

Many of the credits that pertained to Titus products were eliminated or combined with other credits to form new credits. The Materials and Resources section was changed the most of all the sections. Only the Storage and Collection of Recyclables prerequisite and the Construction Waste Management credit were not changed much.

For instance, the most common questions we receive with respect to LEED is whether we meet the requirements of the Recycled Content and Regional Material credits. These two credits are replaced with Building Product Disclosure and Optimization—Environmental Product Declarations and Building Product Disclosure and Optimization—Sourcing of Raw Materials.

Both Building Product Disclosure and Optimization credits are designed to encourage the use of products and materials for which life-cycle information is available and that have environmentally, economically, and socially preferable life-cycle impacts. The Environmental Product Declarations covers the old Regional Material credit, but instead of defining regional as a 500 mile radius, it uses a 100 mile radius. The Sourcing of Raw Materials covers the old Recycled Content credit. This new credit requires that 25% of the building products meet one of several requirements, one of which is that it is recycled.

Many of the credits in the new Materials and Resources section are based on disclosing information related to environmental and health impacts of products going into the building and the life cycle of these materials.

Several credits in the Indoor Environmental Quality section were combined into new credits. We frequently received questions about the paint on our diffusers and the glue for our VAV box liners and whether they complied to the Low Emitting Materials Paints and Coatings and Adhesives and Sealants credits. These are now combined into one credit called Low Emitting Interiors. The new credit is more specific about the paints and adhesives being applied on site, so the paint and adhesives applied to our products at the plants are more clearly not applicable now.

The Controllability of Systems - Thermal Comfort and Thermal Comfort – Design credits have been combined and the Thermal Comfort – Verification credit has been eliminated. To achieve the new combined credits, a building must be designed to ASHRAE Standard 55-2010, Thermal Comfort Conditions for Human Occupancy, (or ISO 7730 or CEN Standard EN 15251) and provide 50% of the occupants with individual comfort control. Underfloor systems and VAV diffusers are still a good way to achieve the individual comfort control portion of this credit.

A new credit for Acoustic Performance has been added to the Indoor Environmental Quality section as well. This credit states that room noise levels from building mechanical systems must be within the sound level ranges shown in 2011 ASHRAE Handbook, HVAC Applications, Chapter 48, Table 1, AHRI Standard 885-2008, Table 15 or a local equivalent. It also has requirements for sound isolation, reverberation time and reverberant noise buildup, and paging, masking, and sound reinforcement systems. There are additional acoustic requirements for schools and healthcare. For schools, it states that the background noise level must be 35 dBA or less from the HVAC systems in classrooms. For healthcare, the building must meet the sound and vibration criteria adapted from the 2010 FGI Guidelines for Design and Construction of Health Care Facilities.

The Energy and Atmosphere section is still the section with the most possible points, primarily due to the Optimize Energy Performance credit.  The previous version of LEED had a prerequisite of meeting ASHRAE 90.1-2007. This has been updated to require a minimum energy performance based on ASHRAE 90.1, 2010. The Optimize Energy Performance credit is also now based on ASHRAE 90.1, 2010. You can achieve up to 20 points for improving the building’s energy usage from 6% to 50%. Another method of achieving this credit is to design using the ASHRAE 50% Advanced Energy Design Guide.

LEED v4 was a dramatically updated version of LEED. Possibly as a response to criticisms that LEED buildings were not performing as designs, LEED v4 has a more performance based focus than previous versions requiring energy monitoring and reporting. It also has a stronger focus on material transparency because, as Beth Heider, USGBC’s 2012 chair, said, “If you create a really tight, energy-efficient building and fill it full of noxious materials, you’ve created the perfect gas chamber.”

Titus has three LEED APs and several LEED Green Associates to help you navigate through your customers’ questions about this new, improved version of LEED.