The International Building Codes
Their Effects on HVAC Systems
&
Historically, building codes change when
lessons are learned after major
catastrophic events such as fires,
earthquakes and wind storms. Such is
the case with the most recent building
codes developed by the International
Code Council (ICC). These building
codes, known collectively as the
International Building Codes (IBC), have
now been adopted by every state in the
United States.
After the Northridge earthquake in
California in 1994, the four National
Earthquake Hazard Reduction Program
(NEHRP) agencies (National Science
Foundation, National Institute and
Standards of Technology, FEMA and
USGS) analyzed the response, recovery
and reconstruction in the aftermath of
the quake.
Philippines Earthquake Detection image © 2008
and provided by Corbis Corporation
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Background
The assessment at
Northridge showed
that while many welldesigned buildings and
structures had high
survival rates, the
mechanical, electrical
and plumbing (MEP)
systems within these
buildings failed,
rendering them
useless. Nine
hospitals closed (2,500
beds lost) and other
emergency services
were impacted. The
aftermath of this
earthquake formed the
basis for the changes
in today's building
codes.
NEHRP and its
corresponding
agencies agreed that a
nationally adopted
model building code
was required in the
United States. This
new building code
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needed to have an
emphasis on the
continued operations
of critical buildings
preparedness,
communication and
operation centers and
other facilities required
critical national defense
functions; and
structures containing
highly toxic
after a natural disaster.
These types of critical
buildings include:
hospitals and other
healthcare facilities;
designated
earthquake, hurricane
and other emergency
facilities; fire, police
and rescue stations;
designated emergency
for emergency
response; most water
treatment facilities and
electrical power
generating stations;
aviation control towers,
air traffic control
centers and hangars
housing emergency
aircraft; buildings and
other structures having
substances.
In the mid 1990s, three
formerly competing
code agencies (ICBO,
SBCCI and BOCA)
joined to form the
International Code
Council (ICC). Their
mission was to take
the recommendations
The International Building Codes
& Their Effects on HVAC Systems
of the NEHRP agencies
and develop a national
model construction
code. The codes they
developed are known
as the International
Building Codes (IBC2000, IBC-2003 and
IBC-2006). To date,
every state has now
adopted one of the
versions of the IBC
Code. Most states
have adopted the code
at the state level and
other states have
adopted versions of the
code at the county level
(see Figure 1 below).
in order to minimize
their exposure to risk
and liability. The
single biggest
with proper anchorage
so that a piece of
equipment would not
become a projectile
These new building
codes are significantly
different from all
previous building
codes. As a result, it is
important for
manufacturers and
equipment suppliers to
fully understand the
provisions of the code
change to equipment
manufacturers,
dealers and installing
contractors is that
equipment needs to be
designed properly and
needs to be anchored
to the building structure
properly. Past seismic
and wind codes only
concerned themselves
during a wind or
seismic event.
Liability
Concerns
The various versions
of the IBC codes hold
architects, engineers,
contractors and
equipment
manufacturers
responsible for the
design and installation
of buildings and their
corresponding MEP
systems. As a state
adopts a version of
the building code, it
becomes the law
governing construction
within the state.
Accordingly,
professional licenses
are potentially at risk
Figure 1. Source: International
Code Council
3
Figure 2.
Source: International Code Council
4
for those that do not
adhere to the
requirement of the law.
seismic event.
Equipment
manufacturers now
need to guarantee this
The focus of the IBC
codes is on building
performance. The logic
is that if MEP systems
are designed to the
same seismic design
force as the building
itself, then those MEP
systems will continue
to operate after a
“on line” performance
through independent
testing and analysis as
outlined in section
1708.5 of the building
code (see Figure 2
below).
That “guarantee”
includes the anchorage
and structural integrity
1708.5 Mechanical and electrical equipment. Each manufacturer
of designated seismic system components shall test or analyze
the component and its mounting system or anchorage and shall
submit a certificate of compliance for review and acceptance by
the registered design professional in responsible charge of the
design of the designated seismic system and for approval by the
building official. The evidence of compliance shall be by actual
test on a shake table, by three-dimensional shock tests, by an
analytical method using dynamic characteristics and forces, by
the use of experience data (i.e., historical data demonstrating
acceptable seismic performance), or by more rigorous analysis
providing for equivalent safety. The special inspector shall
examine the designated seismic system and shall determine
whether the anchorages and label conform with the evidence of
compliance.
The International Building Codes
& Their Effects on HVAC Systems
of the internal
individual components
as well as the
operational survival of
Further defining
1708.5, when an MEP
engineer deems a
product a designated
also be accepted, but
many states have
removed this from their
adopted state code.
that the labeling of the
equipment and
anchorage or mounting
conforms to the
the entire component.
Additionally,
components that utilize
combustible or
flammable energy
sources place high on
the “guarantee list” as
the threat of explosion
from their release is of
significant concern.
seismic system
component, the
manufacturer must
supply a certificate of
compliance stating that
the equipment will
meet the applicable
seismic design criteria
for that project. The
basis for this
compliance can be
done by shake table
The equipment
manufacturer must
also supply a label to
the equipment that
contains sufficient
information for the
inspector to determine
that the installed
product is the same as
that which was
approved during plan
review. The special
previously supplied
manufacturer certificate
of compliance.
Additionally, Authorities
Having Jurisdiction
(AHJ) will look for
product labeling and
certificates of
compliance.
testing or other
analyses such as finite
element modeling.
Historical data may
inspector acts on
behalf of the building
owner or MEP
engineer and verifies
In chapters 16 and 17
of the IBC code, the
ICC lays out the basis
of certification. Two of
the commonly
accepted methods
include shake table
This requirement for
manufacturers, and
consequently their
equipment dealers, is a
departure from all
previous building
codes. Now for the
first time, when a fully
Basis of
Certification
functional system is
required by the code,
equipment
manufacturers and
testing (see Figure 3
at left) and computer
Figure 3. A VMC Group Seismic
dealers are held liable
Curb Prior to Shake Table Testing
for the equipment
performance after
seismic or wind events.
at the University of Buffalo. A
28,000 lb rooftop unit was
installed on the curb and tested
to an SDS value of 2.0.
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Figure 4 (Left). Sample finite
element modeling of a cooling
tower.
Figure 5 (Below). Typical Seismic
and Wind Load Installation of
Roof Top HVAC equipment.
modeling (see Figure
4 above). When shake
table testing
components, strict
adherence to ICC-ES
AC 156 must be
followed. This is the
testing protocol that
outlines the
acceptance criteria for
seismic qualification by
table testing.
shake table. In general,
designing finite
smaller mechanical
components such as
fans, low tonnage a/c
units and condensing
element models and
applying the specified
seismic design forces
to those models.
units can be certified
to the IBC per shake
Large components
such as roof top units
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Larger components are
more easily qualified by
finite element analysis
(FEA), which is another
accepted method of
testing per the IBC
code. Structural
analysis of equipment
is performed by
or air cooled chillers to
name a few are best
suited for finite element
modeling. However, it
is important to note
that their electronic
component
counterparts such as
controllers and junction
boxes should be shake
tested in accordance
with AC-156.
The International Building Codes
& Their Effects on HVAC Systems
When qualifying
products through
analysis, the IBC
codes reference
after earthquakes.
States can accept the
IBC (as written) as the
minimum design
Northridge and
Hurricane Katrina,
proving that buildings
designed to the most
buildings is likely the
most expensive cost to
insurers after a seismic
event. Will the
various versions of the
American Society of
Civil Engineers
document 7 (ASCE 7)
as the standard for
design. The ASCE 7
standards provide
technical guidelines for
the design of buildings
and other structures.
Remember, the IBC
Codes are applying
criteria. However,
states or jurisdictions
within each state can
toughen these
minimum standards
but cannot do anything
to weaken the code.
insurance industry
be willing to pay out
claims for equipment
that was not in
compliance with
the building code
requirements? This
is yet to be seen.
To minimize risk and
liability, equipment
manufacturers,
current building codes
have a higher survival
rate than those which
were not. The industry
concluded that proper
design and installation
does reduce insurance
losses and that failure
to properly design and
install equipment will
lead to lawsuits to
recover part of their
building design
standards to
equipment design!
This is a departure
from all past building
codes.
suppliers, design
professionals and
installing contractors
need to clearly
understand their roles
and responsibilities
as defined in chapters
losses. Policy writers
are expected to set
premiums based on
a building owner's
adherence to the code.
After all, insurance
claims on MEP
reduce their risk is
through proper
education on the code
requirements and how
it applies to them. As
a certifying agency,
The VMC Group can
The IBC codes are the
minimum design
criteria for structures to
minimize earthquake-
16 and 17 of the IBC
code. In recent years,
the insurance industry
has put the mechanical
systems will be
reduced if equipment
has been designed to
the same seismic and
help navigate through
the IBC code and
offer solutions to
meet the labeling
related risk to life and
and electrical
wind load criteria as
and certification
to improve the
capabilities of essential
facilities to function
equipment industry on
notice. Studies have
been done post-
the building. The cost
to replace or repair the
MEP systems within
requirements. ♦
Reducing Risk
The best way for
equipment
manufacturers to
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