BUILDING ENERGY - Fall 2017 - 41

being interrupted. The difference is that
each clip typically requires two screws
(in this case galvanized) that penetrate
the entire insulation layer, while girt
screws only penetrate the sheathing and
structure, not the exterior insulation.
The cumulative heat flow through these
points outweighs the flow through
the continuous thin web in the girts.
Additionally, the effect of a clip system
on the exterior insulation is reduced when
attached to CMU as opposed to a steel
stud backup structure.
Understanding differences between
products early in the design process
can save time and money. Structural
efficiency and cost are closely tied to
the thermal efficiency of a system and
achieving a balance between all three will
be determined by the design of the entire
assembly, from backup system to fa ade
material. This is not as easy a task as it
was even a decade ago. In the world of
low consumption, the recipe for achieving
efficiency calls for an entirely new set
of ingredients.

design and energy modeling research at
Steven Winter Associates. Before working
for SWA, he completed his Master's in
Product Architecture and Engineering at
Stevens Institute of Technology where
he oversaw the energy modeling team
for the SURE House, a storm resistant
Passive House and winner of the 2015
Department of Energy Solar Decathlon. His
current work includes several multi-family
apartment buildings and college dorms
in NYC and around the Northeast U.S.
and Canada.
BUSINESS MEMBER
ABOUT THE PEER REVIEWER
Jordan Goldman is a specialist in energy
modeling and mechanical engineering,
and manages the HVAC design practice for
ZeroEnergy Design. He is fluent in building
envelope strategies and energy efficient
construction systems, building science
design principles, as well as mechanical
system design, specification, and sizing
for enhanced energy performance. He is a
Certified Passive House Consultant, LEED
Accredited Professional, and HERS Rater.
Jordan studied Environmental Engineering
at Cornell University, where he received
both a Bachelor of Science and Master
of Engineering.
BUSINESS MEMBER

ABOUT THE AUTHOR
Chris Hamm is a Building Systems
Engineer focused on Passive House

HEART & SOLAR
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in higher complexity, which can decrease
constructability. Finally, depending on the
project requirements, NFPA 285 testing
may be unavailable for products that are
still new or made from less conductive and
often more flammable materials.
Quantitative factors include cost,
structural efficiency and thermal
efficiency: how do the material costs
compare, and will they be entirely
outweighed by the increase in labor/
detailing later on? How deep is the offset
required for the insulation and ventilation
gap and what is the weight of the fa ade?
Finally, to what degree will the exterior
insulation R-value be degraded as a
result of the thermal bridging from the
attachment system?
While this article does not answer all
of these questions, many resources exist
to provide guidance. For instance, the
Masonry Systems Guide produced by the
Masonry Institute and many publications
by RDH such as their Technical Bulletin
No.11 provide road maps to most of
these systems with regard to detailing,
constructability and thermal performance.
The research presented in this article
evaluates the thermal performance of
several systems assuming a uniform
layout by quantifying the exterior
insulation efficiency. This metric is
commonly used in similar studies to
evaluate exterior cladding attachment
systems and is defined as:
(Modeled R-Value)
Insulation Efficiency =
(Nominal R-Value)
The base cases for this study were
meant to represent typical mid- to
high-rise new construction projects in the
northeast U.S. The goal was to achieve
around an R-30 wall and to evaluate
the effect of each system using two
different backup systems - a 6-inch steel
stud cavity filled with mineral wool and
2 inches of exterior XPS and an 8-inch
CMU wall with a 6-inch interior cavity
and 2 inches of exterior XPS. All clips
were spaced 16 inches horizontally and
24 inches vertically, which is typical if not
the worst-case scenario. The modeling
was done in a three-dimensional thermal
modeling program called Heat3.
This research revealed a few very
interesting observations. First, a
continuous girt made of a low conductivity
material such as fiberglass results in
the lowest reduction in efficiency. It
is counterintuitive that a continuous
fiberglass girt would perform better than
intermittent fiberglass clips - the material
is the same, but there is less insulation

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BUILDING ENERGY - Fall 2017

Table of Contents for the Digital Edition of BUILDING ENERGY - Fall 2017

From the Executive Director: A strategic plan for emerging professionals.
From the Board Chair: Taking flight into new territory.
What is Strategic Electrification? Simply Put, It’s an Energy Transformation: A core pathway to deep carbon reduction.
Better Steam Heat: Generating steam system upgrades in New York City.
Going All the Way:What it will really take to achieve net zero energy in Burlington, VT.
Are You Forging the Weakest Link?: A deeper dive into how the quest for resilience alters the design process.
Air Quality in Your Bedroom: Nighttime Carbon Dioxide Levels in the Bedrooms of 22 Vermont Homes: Can occupants of leaky houses breathe easy in their sleep?
Inclusive Diversity Key to Sustainability: Opinion: Sustainability planning must embrace diversity.
BuildingEnergy Bottom Lines: An interview with Jonathan Orpin.
High Performance Walls: Discover an alternative to traditional insulation methods that can reach superior insulation performance with thinner walls.
SAF®– A Solar Faade to Stay?: A technical overview of the newest attachment systems in the low-energy construction market.
NESEA Green Pages: This premier resource for sustainability professionals in the Northeast and beyond is just a few pages away. To have your business listed in next year’s Green Pages and become a NESEA business member today, visit nesea.org/join.
Index to Advertisers
BUILDING ENERGY - Fall 2017 - Intro
BUILDING ENERGY - Fall 2017 - cover1
BUILDING ENERGY - Fall 2017 - cover2
BUILDING ENERGY - Fall 2017 - 3
BUILDING ENERGY - Fall 2017 - 4
BUILDING ENERGY - Fall 2017 - 5
BUILDING ENERGY - Fall 2017 - From the Executive Director: A strategic plan for emerging professionals.
BUILDING ENERGY - Fall 2017 - 7
BUILDING ENERGY - Fall 2017 - From the Board Chair: Taking flight into new territory.
BUILDING ENERGY - Fall 2017 - 9
BUILDING ENERGY - Fall 2017 - What is Strategic Electrification? Simply Put, It’s an Energy Transformation: A core pathway to deep carbon reduction.
BUILDING ENERGY - Fall 2017 - 11
BUILDING ENERGY - Fall 2017 - 12
BUILDING ENERGY - Fall 2017 - 13
BUILDING ENERGY - Fall 2017 - 14
BUILDING ENERGY - Fall 2017 - 15
BUILDING ENERGY - Fall 2017 - Better Steam Heat: Generating steam system upgrades in New York City.
BUILDING ENERGY - Fall 2017 - 17
BUILDING ENERGY - Fall 2017 - 18
BUILDING ENERGY - Fall 2017 - 19
BUILDING ENERGY - Fall 2017 - INSERT1
BUILDING ENERGY - Fall 2017 - INSERT2
BUILDING ENERGY - Fall 2017 - Going All the Way:What it will really take to achieve net zero energy in Burlington, VT.
BUILDING ENERGY - Fall 2017 - 21
BUILDING ENERGY - Fall 2017 - 22
BUILDING ENERGY - Fall 2017 - 23
BUILDING ENERGY - Fall 2017 - Are You Forging the Weakest Link?: A deeper dive into how the quest for resilience alters the design process.
BUILDING ENERGY - Fall 2017 - 25
BUILDING ENERGY - Fall 2017 - 26
BUILDING ENERGY - Fall 2017 - 27
BUILDING ENERGY - Fall 2017 - 28
BUILDING ENERGY - Fall 2017 - 29
BUILDING ENERGY - Fall 2017 - Air Quality in Your Bedroom: Nighttime Carbon Dioxide Levels in the Bedrooms of 22 Vermont Homes: Can occupants of leaky houses breathe easy in their sleep?
BUILDING ENERGY - Fall 2017 - 31
BUILDING ENERGY - Fall 2017 - 32
BUILDING ENERGY - Fall 2017 - 33
BUILDING ENERGY - Fall 2017 - Inclusive Diversity Key to Sustainability: Opinion: Sustainability planning must embrace diversity.
BUILDING ENERGY - Fall 2017 - 35
BUILDING ENERGY - Fall 2017 - BuildingEnergy Bottom Lines: An interview with Jonathan Orpin.
BUILDING ENERGY - Fall 2017 - 37
BUILDING ENERGY - Fall 2017 - High Performance Walls: Discover an alternative to traditional insulation methods that can reach superior insulation performance with thinner walls.
BUILDING ENERGY - Fall 2017 - 39
BUILDING ENERGY - Fall 2017 - 40
BUILDING ENERGY - Fall 2017 - 41
BUILDING ENERGY - Fall 2017 - SAF®– A Solar Faade to Stay?: A technical overview of the newest attachment systems in the low-energy construction market.
BUILDING ENERGY - Fall 2017 - 43
BUILDING ENERGY - Fall 2017 - 44
BUILDING ENERGY - Fall 2017 - 45
BUILDING ENERGY - Fall 2017 - 46
BUILDING ENERGY - Fall 2017 - 47
BUILDING ENERGY - Fall 2017 - NESEA Green Pages: This premier resource for sustainability professionals in the Northeast and beyond is just a few pages away. To have your business listed in next year’s Green Pages and become a NESEA business member today, visit nesea.org/join.
BUILDING ENERGY - Fall 2017 - 49
BUILDING ENERGY - Fall 2017 - 50
BUILDING ENERGY - Fall 2017 - INSERT3
BUILDING ENERGY - Fall 2017 - INSERT4
BUILDING ENERGY - Fall 2017 - 51
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BUILDING ENERGY - Fall 2017 - 74
BUILDING ENERGY - Fall 2017 - 75
BUILDING ENERGY - Fall 2017 - 76
BUILDING ENERGY - Fall 2017 - Index to Advertisers
BUILDING ENERGY - Fall 2017 - 78
BUILDING ENERGY - Fall 2017 - cover3
BUILDING ENERGY - Fall 2017 - cover4
BUILDING ENERGY - Fall 2017 - outsert1
BUILDING ENERGY - Fall 2017 - outsert2
BUILDING ENERGY - Fall 2017 - outsert3
BUILDING ENERGY - Fall 2017 - outsert4
BUILDING ENERGY - Fall 2017 - outsert5
BUILDING ENERGY - Fall 2017 - outsert6
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