Page 178 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

156 Cha pte r F o u r

FIGURE 4.1.2 Trane TRAQ damper which balances air intake for both indoor air quality and
energy performance. (Photograph Courtesy of Trane.)

energy. Figure 4.1.3 depicts a Trane energy wheel. This wheel is part of an HVAC system
and is used to reduce energy demand. It can recover energy from the conditioned
exhaust air and uses it to pretreat the incoming outside air. Another developing concept
in improving efficiencies is the idea of thermal energy storage (TES), where cooling
energy is transferred into storage via mechanisms such as chilled water or ice during
off-peak hours and is then used during peak hours. This technique reduces the demand
on the equipment and the energy network. These are just a few of the examples of how
energy efficiencies can be improved.
Options 2 and 3 are prescriptive-based options. They have requirements where
certain specific actions must be taken which are the opposite of design-based
performance requirements, where many different actions may result in the same level
of performance. (The definition of prescriptive requirements is further explained in
EAp2.) Options 2 and 3 are summarized in Table 4.0.3. There are no calculations for
Option 2 or Option 3. Details of the prescriptive measures are not a part of this book but
can be found in the LEED-NC 2.2 and 2009 Reference Guides.

Option 1 The performance modeling procedures and various standard energy models used
for Option 1 are not a detailed part of this book. However, there are a few items relating to