Page 231 - Green Building Through Integrated Design

ENERGY DESIGN QUESTIONS 207

point we started looking at equipment selection and more basic control strategies.
That level of design consideration comes up after design development, typically.
In the construction documents phase, we then updated the model a couple of times.
Mostly at that time we were looking at refinements in the architecture—the type of
glass, for example—or we were looking at control strategies in the HVAC. It was a stan-
dard process for us, but what was unique about it was how responsive the architects
were. The design really moved a lot based on our input and the architects’critical review
of this work with us. We were able to give more and better input than normal. Because
they responded so quickly, we could do more and go further along in the design together
in the amount of the time we had. It was truly an iterative process. [In the design devel-
opment phase], we certainly looked at wall performance in great detail. There was a
long discussion about the south façade, specifically whether it should be a double
façade, which turned out to be prohibitively expensive (and we had some concerns
about controls and reliability.) In the end, it became an externally shaded façade. Then
®
Kieran Timberlake proposed backing up the spandrel glazing with Nanogel -filled
panels to make an exceptionally high-performance curtain wall. Kieran Timberlake
used [Kalwall’s] highest performing panel which is filled will an ultra-lightweight,
high-translucent insulation, called Nanogel. It’s exciting to use Nanogel because it per-
forms so well, also it was interesting because the architects located the Kalwall inside
the glazing, instead of its typical location as an external wall panel. Aside from the
façade analysis work, we probably did more work on modeling HVAC on this project
than we would do some other projects, to really confirm our hunches about the energy
benefits of displacement ventilation and heat recovery ventilation.

Here are some key questions you can ask during design development phase, to make sure
nothing has been overlooked that could significantly reduce energy use in the building.

1 Have we prepared hourly simulation models of the building design to assess
energy-efficiency measures, before 50 percent design development?
2 Have we used this model to evaluate various envelope and system measures?
3 What is the size and location of all thermal mass in the project; can this mass be
used as part of the heating and cooling properties of the building?
4 Can we use the project’s natural ventilation goals as an approach to help us refine
the sizing of windows and internal openings?
5 Can we train staff to operate and maintain the systems we are planning to use? If
not, are there outside contractors who will be required to operate our facility?
6 Can the design take advantage of cooling strategies such as “night flushing” of the
building or thermal energy storage to reduce mechanical cooling demand or shift
its peak, thereby saving operating costs for utilities?
7 Are there innovative strategies for climate control, water system management and
similar systems that are either economically feasible now or cost-effective over
the life cycle of the building?
8 How will we document compliance with state energy codes applicable to this
project? Will there be energy models integrated with our building information
modeling (BIM) software?