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by Dick Price
As business development manager for the Infrared Training Center,
there's nothing I enjoy more than sharing infrared technology success
stories.
One of my favorites comes from Scott Wood, division manager for
the Environmental Division of Four Star Cleaning and Restoration
in Fremont, Calif. According to Wood, a leak appeared in the kitchen
ceiling of a $3 million home in a gated community. The homeowner
assumed the water was coming from an upstairs bathroom, directly
over the kitchen. The 8x8x6-foot bathroom was completely paneled
in marble. The cost to rip out the marble, identify the problem,
make the necessary repairs and replace the marble was estimated
at $80,000. But when the homeowner mentioned that the leak occurred
after rainstorms, it was decided to use the FLIR Systems infrared
camera. An inspection with the camera located an 8-foot wide path
of wet materials leading to the threshold of a French door that
opened to an upstairs porch. The water wasn't coming from the bathroom
after all. The clogged weep hole under the threshold was opened,
and this quick, simple repair took care of the problem, saving the
homeowner the major inconvenience of tearing up the bathroom and
from wasting $80,000!
I also like the success story about infrared being used in the
entryway of a home to determine that the under-floor radiant line
spacing was below the designer's specified instructions. Infrared
also can be used to view different radiant flooring heat zones,
crimps in tubing and other post-installation validation concerns,
often saving time and unnecessary destructive investigation. And
in yet another home, an IR image immediately identified the source
of energy loss-missing insulation on the roof and rafters.
These success stories are possible because infrared (IR) thermography,
also called thermal imaging, can instantly detect moisture in building
materials as, typically, wet areas on interior building surfaces
are cooler by several degrees Fahrenheit than materially similar,
but dry, areas. As a result, an IR camera can be a useful tool in
identifying moisture water intrusion. Because mold requires moisture
to grow, the camera can be helpful in identifying likely areas of
mold contamination.
But detecting moisture intrusion and possible mold is just one
of the ways infrared technology is being used to diagnose the condition
of building envelopes and components. There are some additional
ways it's being used.
Detecting missing or damaged insulation
An IR camera can quickly and non-destructively detect areas of missing,
moisture-laden or otherwise damaged insulation in walls, crawlspaces
and attics or around doors, windows, electrical outlets and other
access plates. All of these problems can increase a building's energy
costs by allowing cold air to enter the building and heated air
to escape in the winter and the reverse in the warmer, summer months.
IR can also identify poorly insulated or uninsulated pipes, another
source of costly heat loss.
Detecting faulty electrical-mechanical and HVAC systems and
components
Infrared cameras are used to detect overloaded circuits, faulty
wiring and loose electrical connections because they all generate
heat. IR can detect thin spots in furnace heat exchangers and flues,
mechanical problems such as worn, under-lubricated pumps, motors
and bearings in fans, compressors and furnaces, electrical faults,
refrigerant leaks and blockages in HVAC components.
Detecting leaking roofs
An infrared camera in the hands of a trained inspector can identify
missing or moisture-soaked insulation under a flat roof membrane
roof where the insulation needs replacement, permitting the surgical
repair of failed areas rather than the more costly replacement of
the entire roof.
Finding construction defects
The increased use of EIFS (Exterior Insulation and Finish Systems)
and stone, stucco, brick veneers and siding as facades on residential,
as well as commercial, buildings invites the possibility of water
intrusion if they are not properly installed. IR can detect or verify
moisture infiltration in these weatherproofing 'barrier' systems,
usually the result of insufficient detailing such as inadequate
or improperly applied flashing or sealants. In addition, IR can
monitor and track moisture migration paths within the wall cavity.
Conducting post-fire inspections
After fires, IR can quickly locate remnant hot spots, assuring the
fire is completely extinguished and provide invaluable data for
insurance companies' cause and origin investigations. The clear
IR images of normally invisible diagnostic evidence can assist in
the planning and execution of the restoration effort and in the
settlement process.
Even termites
Although considered cold-blooded creatures, termites are hosts to
bacteria, which help break down and digest cellulose, the main ingredient
of the wood they digest. The digestion process generates heat, and
when large numbers of termites in nests congregate, a substantial
amount of heat is concentrated in one area. As this heat moves through
the walls or floor of a building, an IR camera can detect it on
the surface.
In addition, infrared is being used to perform energy audits and
surveys, indoor air quality investigations, and plumbing and radiant
floor heating inspections.
Limitations
IR covers so much more area and gets into many places not accessible
to moisture meters, which require contact with the surface being
inspected; it finds things that would never have been found with
a moisture meter alone.
But there is still a role for moisture meters. Infrared, which
can quickly locate the probable presence of moisture by identifying
temperature variations as slight as +/- 0.25° F in building
structures, can't detect moisture per se or how much is present.
For that, you still need a moisture meter to identify an abnormality
you might see on an IR thermogram, and to confirm that the temperature
differential you're seeing is actually an indication of moisture
and not something else, such as an insulation void or multiple layers
of building material.
In addition, thermal imagers show all types of differences in temperatures.
An air leak (infiltration) and water can look virtually the same
in the infrared image. Moisture meters are the better instruments
to make the final determination.
The combination of IR and moisture meters can mean little or no
destructive testing is required, allowing for substantial savings
for the building owner, or homeowner or other responsible party.
The need for training
Regardless of what an IR camera is used to look for or at, its effectiveness
is dependent on two factors:
- The inspector's knowledge and understanding of the component
being inspected,
- The inspector's skill in operating the camera and his or her
understanding of the science involved in the assessment of the
thermal evidence.
The trained and experienced thermographer knows that every hot
or cold spot does not represent a problem, but may, in fact, reflect
a component's normal operation, performance or location in the structure.
Alternatively, a thermal image may actually show heat from sources
other than the target that is reflected from or transmitted through
the target material.
How Infrared Thermography Works
Thermography enables us to see and measure heat. All materials on
earth emit heat energy in the infrared portion of the spectrum.
The unaided human eye cannot see in the infrared. Thermographic,
or simply thermal, images, allow the user to see thermally, revealing
anomalies that might be indicative of problems in buildings and
their component electrical, mechanical, plumbing and waterproofing
systems. Today's lightweight and rugged infrared cameras see in
real-time, record infrared images and measure the temperatures of
target objects quite accurately-to within +/- 0.25° F. Points
of possible concern show up clearly as hot or cold in relation to
their surroundings. Recorded thermal images can be easily inserted
into reports and distributed by e-mail, facilitating communications
among trades, attorneys and other professionals, and serving as
evidentiary data in cases involving controversy.
Copyright Infrared Training Center, Published September 2005
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Why
are these people smiling?
