U.S. patent application number 12/234958 was filed with the patent office on 2009-02-19 for nondestructive residential inspection method.
Invention is credited to Peng Lee, Kevin J. Seddon.
Application Number | 20090046759 12/234958 |
Document ID | / |
Family ID | 40160444 |
Filed Date | 2009-02-19 |
United States Patent
Application |
20090046759 |
Kind Code |
A1 |
Lee; Peng ; et al. |
February 19, 2009 |
Nondestructive Residential Inspection Method
Abstract
This invention provides an apparatus for nondestructive
residential inspection and various methods for using a thermal
imaging apparatus to inspect residential building components. More
specifically, this invention provided a method to rapidly inspect a
residential building for moisture in basement walls, uninsulated
building components, misaligned structural members or small animal
intestation.
Inventors: |
Lee; Peng; (Oxford, MS)
; Seddon; Kevin J.; (Oxford, MS) |
Correspondence
Address: |
Susan B. Fentress
6060 Poplar Ave., Suite 440
Memphis
TN
38119
US
|
Family ID: |
40160444 |
Appl. No.: |
12/234958 |
Filed: |
September 22, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10708571 |
Mar 11, 2004 |
7445377 |
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12234958 |
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60453856 |
Mar 12, 2003 |
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Current U.S.
Class: |
374/5 |
Current CPC
Class: |
G01N 25/72 20130101 |
Class at
Publication: |
374/5 |
International
Class: |
G01N 25/72 20060101
G01N025/72 |
Claims
1. A method to rapidly inspect residential building basement walls
comprising the steps of: preparing a residential building for
inspection by creating a temperature differential of greater than
10.degree. F. between the inside and the outside of said
residential building and creating sufficient air flow in said
basement to facilitate contrast in the temperature profiles; and
then obtaining temperature profiles of the basement walls; and
assessing each of said temperature profiles to detect a thermal
anomaly indicative of moisture; wherein said steps up to the step
of assessing each of said profiles occur within 4 hours.
2. A method to rapidly inspect interior residential building
components for uninsulated interior building components comprising
of the steps of: preparing a residential building for inspection by
creating a temperature differential of greater than 10.degree. F.
between the inside and the outside of said residential building;
and then obtaining temperature profiles of said interior building
components; wherein said interior building components are selected
from the group consisting of wall and ceiling and said thermal
anomaly is indicative of an uninsulated interior building
components.
3. A method to rapidly inspect residential building components for
damage to insulation by small animals comprising of the steps of:
preparing a residential building for inspection by creating a
temperature differential of greater than 10.degree. F. between the
inside and the outside of said residential building; and then
obtaining temperature profiles of said and the interior building
components wherein said interior building components is selected
from the group consisting of a wall and a ceiling and said thermal
anomaly is indicative of damage to insulation by small animals.
4. A method to rapidly inspect interior residential building
components for misaligned structural members comprising of the
steps of: preparing a residential building for inspection by
creating a temperature differential of greater than 10.degree. F.
between the inside and the outside of said residential building;
and then obtaining temperature profiles of said interior building
components; wherein said interior building components is selected
from the group consisting of a wall and a ceiling and said thermal
anomaly is indicative of misaligned structural member.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. Ser.
No. 10/708,571. This Application claims the benefit of U.S.
Provisional Application No. 60/453,856 filed Mar. 12, 2003 under 35
U.S.C. Section 119(e) and U.S. Ser. No. 10/708,571 hereby
specifically incorporated by reference in their entirety).
FIELD OF THE INVENTION
[0002] This invention relates to the field of nondestructive
residential inspection.
BACKGROUND OF INVENTION
[0003] Infrared thermography (thermal imaging scan) has been used
in industrial electrical, mechanical, and boiler evaluations. In
these applications, true temperature measurements are made of the
structure being evaluated. True temperature evaluations require
expensive time to take temperature measurements. Additionally,
infrared imaging is used for (ASTM standard #C-1153) locating wet
insulation in flat roof system. Most commercial, industrial, and
institutional roofs are flat roofs. There is no guideline or
standard for pitched roofs inspection using thermal imaging.
Infrared thermography has also been used to provide "energy audits"
of homes (ISO 6781 and ASTM C 1090-90) and industrial electrical
panel inspections. More specific, diagnostic applications of
infrared technology for residential applications, however, require
greater contrast between building components shown in the scanned
images.
SUMMARY OF INVENTION
[0004] This invention provides a method to conduct a complete
inspection of a residential building. A complete inspection
includes the steps of: conducting an infrared scan of a residential
building, conducting a visual home inspection and conducting an
acoustic scan to detect wood destroying insects. The term infrared
scan of a residential building includes all of the methods
discussed infra in the section on infrared scanning methods.
[0005] This invention further relates to the following methods and
devices for inspecting residential buildings. This method includes
a thermal imaging (infrared) camera for looking into, examining and
evaluating a building's structural and systemic components, such as
walls, insulation, electrical wiring, heating, air conditioning and
plumbing. This method captures temperature profiles, which provide
valuable information to evaluate and/or further investigate
problems in the building. Additionally, this method includes
procedures for creating favorable conditions for a thermal imaging
scan to detect concealed and/or nonconcealed conditions of the
building's components.
[0006] More specifically, this invention relates to a method to
rapidly inspect residential building components for a designated
entity such as a home owner, a realtor, an insurance company or any
designated party. This method involves creating a temperature
differential of greater than 10.degree. F. between the inside and
the outside of the residential building. It also involves turning
on substantially all light switches and substantially all exhaust
blowers in the residential building and obtaining temperature
profiles of the exterior residential building components selected
from the group consisting of wall, eave and facia. It also involves
obtaining temperature profiles of the interior surface of a pitched
roof; obtaining temperature profiles of the interior residential
building components; and obtaining temperature profiles of each
electrical circuit in a residential building. Additionally, this
invention relates to creating sufficient air flow in a basement to
facilitate evaporation; and obtaining temperature profiles of a
basement wall and assessing each of the temperature profiles to
detect a thermal anomaly indicative of a problem with the
residential building components; and reporting a problem to the
designated entity.
[0007] It is a first objective of the invention to provide a
nondestructive yet reliable method and apparatus for more accurate
assessment of the condition of a residential building's components
very quickly and to provide good record-keeping in regard to the
building's condition.
[0008] It is a second objective of the invention to provide a
procedure that creates a significant variation in temperature among
the building's components in relation to the temperature outside
the building. This process is carried out by introducing cold or
heated air to the building, either through the building's own
heating or cooling through external injection of cold or hot air to
the building's interior.
[0009] These objectives are achieved, in accordance with the
principles of a first preferred embodiment of the invention, by
providing a method and apparatus for monitoring and recording the
temperature profiles of a building's components and structure.
[0010] Traditional home inspection primarily involves human visual
inspection of a building's components. Since the human eye cannot
see through walls and other solid objects, traditional visual
inspection is limited to the surface level. Our preferred
embodiment employs a thermal imaging sensor (infrared camera) that
allows the inspector to view and inspect beyond the surface level
through evaluation of the temperature profiles of building
components due to the difference in thermal properties between
building components.
[0011] The overall goal of the thermal imaging (infrared) home
inspection system is to detect problems in buildings accurately and
as early as possible. Early and accurate detection of a building's
problems reduces further damage and provides valuable, more
accurate and realistic information to all concerned parties, such
as the building owner, the building seller, the real estate
company, the loan company, the insurance company and, most
important, the buyer.
[0012] Infrared detection has the advantage of covering a large
area. It provides efficient screening and a convenient way of
scanning the structure for potential problems in order to alert the
inspector to carry out a more specific inspection.
[0013] In accordance with another aspect of the preferred
embodiment of the invention, the infrared scan is combined with a
procedure to create a temperature differentiation between indoor
and outdoor areas. This procedure provides the infrared camera with
favorable conditions for scanning.
[0014] Because different seasons of the year generate different
weather conditions, a building experiences large fluctuations of
temperature, humidity and atmospheric pressure changes. At certain
times of the year, such as spring and the outdoor temperature can
be very close or equal to the indoor temperature. This reduction of
the difference between indoor and outdoor temperatures greatly
reduces thermal imaging (infrared) device's ability to "see" inside
the building's components.
[0015] The preferred procedure of the invention creates a larger
temperature contrast between the building's components, thus
greatly increasing the effectiveness of the thermal imaging system.
The bigger the temperature contrasts between the building's
components, the better the temperature profiles will be.
[0016] In the other preferred embodiment these images of
temperature variations can be recorded with a digital or analog
image-recording device such as a camcorder.
[0017] Finally, according to yet another aspect of the preferred
embodiment of the invention, recorded temperature profiles taken at
each inspection site using the above-summarized methods and
apparatus may be provided to a central operations unit for use in
building a central database of information. The central operations
unit may operate on a nationwide or even worldwide basis and serve
as a facility of data communications, data acquisition, data
analysis, continuous updating of temperature profiles, references
and aggregation of inspection results. The accumulated data may be
made available to entities interested in the building's condition,
thereby providing an invaluable resource of building information.
No such centralized resource is currently available.
BRIEF DESCRIPTION OF DRAWINGS
[0018] FIG. 1 is a schematic illustration of a nondestructive
thermal imaging apparatus in accordance with the principles of a
preferred embodiment of the invention.
[0019] FIG. 2 is a schematic illustration of a nondestructive
thermal imaging apparatus in accordance with the principles of a
preferred embodiment of the invention.
[0020] FIG. 3 is a schematic illustration of an alternate
embodiment of the apparatus.
[0021] FIG. 4A is a visual photograph of an EIFS wall.
[0022] FIG. 4B is a temperature profile of an EIFS wall.
[0023] FIG. 5A is a temperature profile of vinyl siding.
[0024] FIG. 5B is a temperature profile of vinyl siding.
[0025] FIG. 6 is a temperature profile of an eave.
[0026] FIG. 7 is a temperature profile of an EIFS wall.
[0027] FIG. 8 is a temperature profile of a wooden wall.
[0028] FIG. 9 is a temperature profile of a brick wall.
[0029] FIG. 10A is a temperature profile of the interior surface
underside of a roof.
[0030] FIG. 10B is a temperature profile of the interior surface
underside of a roof.
[0031] FIG. 10C is a temperature profile of the interior surface
underside of a roof.
[0032] FIG. 11 is a temperature profile of electrical
component.
[0033] FIG. 12 is a temperature profile of an electrical
component.
[0034] FIG. 13A is a temperature profile of an electrical
component.
[0035] FIG. 13B is a temperature profile of an electrical
component.
[0036] FIG. 13C is a temperature profile of an electrical
component.
[0037] FIG. 13D is a temperature profile of an electrical
component.
[0038] FIG. 13E is a temperature profile of an electrical
component.
[0039] FIG. 14A is a schematic drawing of a method to scan.
[0040] FIG. 14B is a schematic drawing of a method to scan.
[0041] FIG. 14C is a schematic drawing of a method to scan.
[0042] FIG. 15 is a temperature profile of a residential interior
component.
[0043] FIG. 16 is a temperature profile of a residential interior
component.
[0044] FIG. 17 is a temperature profile of a residential interior
component.
[0045] FIG. 18 is a temperature profile of a residential interior
component.
[0046] FIG. 19 is a temperature profile of a residential interior
component.
[0047] FIG. 20A is a temperature profile of a residential interior
component.
[0048] FIG. 20B is a temperature profile of an air conditioning
duct.
[0049] FIG. 21A is a temperature profile of a residential interior
component.
[0050] FIG. 21B is a temperature profile of a residential interior
component.
[0051] FIG. 21C is a temperature profile of a residential interior
component.
[0052] FIG. 21D is a temperature profile of a residential interior
component.
[0053] FIG. 22 is a temperature profile of a residential interior
component.
[0054] FIG. 23 is a temperature profile of a residential interior
component.
[0055] FIG. 24 is a temperature profile of a residential interior
component.
[0056] FIG. 25 is a temperature profile of a residential interior
component.
[0057] FIG. 26 is a temperature profile of a residential interior
component.
[0058] FIG. 27 is a temperature profile of a residential interior
component.
[0059] FIG. 28 is a temperature profile of a residential interior
component.
[0060] FIG. 29 is a temperature profile of a residential interior
component.
[0061] FIG. 30 is a temperature profile of a residential interior
component.
[0062] FIG. 31 is a temperature profile of a residential interior
component.
DETAILED DESCRIPTION OF THE INVENTION
[0063] A home inspection is a thorough visual examination of a
home's structural and systemic condition. A home inspection
evaluates the physical condition of the home, identifies items that
may need repair or replacement and identifies systems and
components that are nearing the end of their service life.
[0064] Because a home purchase is one of the biggest investments a
person will ever make, a home inspection is crucial in providing
valuable information about the investment. It also assists in
protecting against unknown and costly repairs that may not be
obvious to the untrained eye. Items covered typically include the
property's wall, roof, structural components and major electrical,
plumbing and operating systems.
[0065] Major areas of investigation in a home inspection include:
I. Improper electrical wiring, such as open ground, hot and neutral
reverse, inadequate overload protection, and hazardous wiring
connections; II. Roof damage and leakage caused by old or damaged
shingles and improper flashing; III. Poor overall maintenance as
evidenced by such signs as cracked; makeshift wiring or plumbing;
broken fixtures; IV. Structural issues, including damage to such
structural components as foundation walls, floor joists, rafters
and window and door headers; V. Improper surface grading and
drainage problems, such as water penetration into the basement area
or crawl spaces; VI. Flaws in the home's exterior, including doors,
windows, door and wall surfaces, which may result in air or water
penetration. Inadequate caulking or weather stripping are common
culprits; VII. Ventilation problems which may result in excessive
interior moisture, rotting and premature failure of both structural
and nonstructural elements; and VIII. Depending on location,
miscellaneous concerns such as the presence of mold,
wood-destroying insects, able to see signs of rodents in the
ceiling.
[0066] A home inspection to be of value to a home owner needs to be
complete; however, a residential inspection to be affordable must
be completed within a reasonable period of time. This invention
provides a method to conduct a complete inspection of a residential
building within a cost effective period of time, two hours for a
residential building of 2,000 sq. ft. or less, and four hours for a
residential building between 3,000 to 4,000 sq. ft. The complete
inspection includes several parts. One part is an infrared scan of
the residential building. This type of inspection is discussed in
detail, infra. Another part of a complete or "traditional"
inspection is a visual inspection. A visual inspection is defined
by ASHI, NAHI, and NABIE protocols. Another part of the inspection
is an acoustic scan of the residential building for wood destroying
insects such as termites. The procedures to conduct termite
acoustic detection are set out in U.S. Pat. No. 7,271,706 (hereby
specifically incorporated by reference in its
entirety--specifically, the software program at pages 28 through 42
which facilitates the acoustic detection of wood destroying
insects). A report can be generated which summarizes all portions
of the inspection.
[0067] Infrared Scanning Methods and Apparatus--Infrared scanning
works because different parts of a building's components retain
different temperatures due to the individual component type's
thermal properties, such as heat capacity, heat transmission, heat
retention and heat dissipation. The difference between indoor and
outdoor temperatures creates a temperature gradient, causing the
heat to transmit from high temperature areas to low temperature
areas. Due to the different thermal properties of different
residential building components, heat transmits and dissipates
through these different residential at different rates.
[0068] Take a building's wall in the summertime, for example: When
scanning the interior wall with an infrared camera, fiber grain
insulation transmits much less heat than a 2.times.4 stud; the
2.times.4 stud thus has a higher temperature which can be easily
registered by the infrared sensor (camera). Infrared detection also
has the advantage of covering a larger area very quickly and
provides the inspector with critical information about potential
problem areas in order to guide the inspector to carry out more
specific tests and inspections.
[0069] Because different seasons of the year generate different
weather conditions, a building experiences large fluctuations of
temperature, humidity and atmospheric pressure changes. At certain
times of the year, such as spring and fall, the outdoor temperature
can be very close or equal to the indoor temperature. This
reduction of the difference between indoor and outdoor temperatures
greatly reduces the thermal imaging (infrared) device's ability to
"see" inside the building's components.
[0070] The preferred procedure of the invention creates a larger
temperature contrast between the building's components, thus
greatly increasing the effectiveness of the thermal imaging system.
The bigger the temperature contrasts between the building's
components, the better the temperature profiles will be. The
procedure involves activating the building's own heating or cooling
system for a certain period of time prior to the inspection. The
duration can be as brief as one minute to as lengthy as a few
hours, depending on the size (capacity) of the tem and the size and
condition of the building. At a certain point of the heating or
cooling process, the temperature contrast reaches a workable
condition for the thermal imaging sensor. Therefore, the inspector
will have to periodically check the conditions with the thermal
imaging camera. The decision to activate either the heating or
cooling mode of the building's heating/cooling system will depend
on the outdoor temperature. A preferred rule of thumb is to let the
inspector make this judgment: If he feels it's cold outside (below
70.degree. F.), he will activate the heating system; if he feels
that it's hot outside (above 70.degree. F.), he will activate the
cooling system. In the event that the building is not equipped with
a heating or cooling system, an external heating or cooling unit
can be employed to achieve a similar effect. In this method, a
temperature differential of greater than 10.degree. F. between the
inside and the outside of the building is created. This can be
achieved by running either the heating or air conditioning system
until the desired temperature differential is obtained.
[0071] As schematically illustrated in FIG. 1, the preferred
embodiment of the invention includes a thermal imaging (infrared)
camera 1 for performing a scan of residential building components
in order to locate potential problems in the building. An infrared
camera is an apparatus that converts the spatial variations in
infrared radiance from a surface into a two-dimensional image, in
which variations in radiance are displayed as a range of colors or
tones. In this application, it is preferred that the image is
displayed as tones, with dark shades representing cold and shades
representing hot infrared radiance. This is commonly called the
gray scale. Gray scale work is best for home inspection because it
is less confusing; however, color is also sufficient for home
inspection.
[0072] The temperature profiles created by the thermal imaging
camera can be assessed to detect a thermal anomaly indicative of a
problem with the residential building components. In the preferred
embodiment, each of the temperature profiles is assessed for an
anomaly; however, in certain situations where time is limited or a
specific problem is being addressed, at least one of the thermal
anomalies are assessed for a problem.
[0073] A problem in a residential building component will appear as
an anomaly in a temperature profile. An anomaly is any deviation
from the normal characteristics of a specific type of residential
building component. FIGS. 4, 13 A-E and 15-31, show a series of
normal temperature profiles and temperature profile anomalies. A
temperature profile anomaly is indicative of a problem with the
residential building component. These building problems include but
are not limited to the following: structure, insulation, moisture,
electrical hot spots, water leakage, unwanted pests such as
termite, mice, and rats, and air duct leakage. The term residential
building include elements of a building, such as walls, ceilings,
windows, plumbing fixtures, etc. The residential building component
can be an exterior component, such as exterior wall (wood, bricks,
stucco, or vinyl siding), eaves, fascias and interior surface of a
pitched roof. Similarly, the residential building component can be
the electrical system. Additionally, the residential building
component can be an interior structure, such as insulation, wiring,
air duct, and finished surfaces.
[0074] The corresponding video images of the potential building
problems are recorded by digital video camera 2. A digital video
camera 2 is a means to record a digital image. The thermal imaging
camera 1 is connected to digital video camera 2 by cable 5. The
video output of the infrared camera 1 is input to the video
recording device. Thermal imaging camera 1 may be any of a number
of commercially available infrared cameras conventionally used by
structural engineers, police and the military. In order to improve
the accuracy by which thermal imaging camera 1 detects potential
problems, the thermal imaging may further include target
recognition software, such as matched filtering software which
compares the frequency spectra of reference images, thereby
reducing the level of skill required of the camera operator.
[0075] While the invention is not limited to a particular thermal
imaging (infrared) camera 1, there are various thermal imaging
systems that are sensitive enough and capable of evaluating
residential building components. For example, Raytheon's Control
IR2000B or 300D thermal imaging system, although not the most
sensitive, has shown good consistency and accuracy. It is robust
and, most importantly, relatively inexpensive. Those skilled in the
art will appreciate that it is also possible to use other types of
thermal imaging cameras 1 so long as they are sufficiently
sensitive to detect temperature variations normally down to 0.12
degrees Celsius or lower (e.g., 0.08 degrees Celsius) and cover an
approximate frequency range of the infrared spectrum emitted by
residential building components. The infrared detector resolution
is preferably 240.times.320 or higher; but can be 120.times.160
(with a good thermal window). It will, of course, be appreciated by
those skilled in home inspection that the thermal imaging camera 1
and the digital video camera 2 may be combined into a combination
unit 6 as shown in FIG. 3. However, a combination unit 6 presently
carries a much higher price tag, which makes the residential
application much less attractive.
[0076] While one particularly preferred embodiment is the new
arrangement specifically designed to securely position the device
in front of the inspector for ease of operation, out of harm's way
to protect the sensitive infrared camera, and to allow the
inspector to have both hands free when needed to move an object. As
shown in FIG. 1, a harness apparatus 3 allows both the thermal
imaging camera and the digital video camera 2 to be mounted in a
balanced, safe and easy-to-use position for the inspector. As shown
in FIG. 2, the harness apparatus 3 is designed to be securely
mounted over the inspector's shoulders. The harness apparatus 3
allows the operator to operate with his hands with the aid of the
handles 4 or without hands in the event that the hands need to be
free to perform other functions, with add chest support (not shown)
The harness apparatus 3 is configured to support at least one
residential inspection device. The residential inspection device
can include, for example, a thermal imaging camera, a thermal
imaging camera, video recording device, a means to transmit or
record a digital video image, such as a LCD or a digital camera, a
combination unit thermal imaging camera recording and a wireless
apparatus.
[0077] More specifically, the harness apparatus 3 in the preferred
embodiment has a first portion 7 for supporting at least part of a
thermal imaging camera 1 and if desired at least part of the video
recording device 2 such as a digital video camera. In this
embodiment, the thermal imaging camera 1 and the video recording
device 2 are attached to the first portion 7 of the harness 3. This
first portion 7 is connected to a second portion 8. The first and
second portions form an enclosure. The enclosure is of sufficient
size to accommodate a human torso as shown in FIG. 2. The thermal
imaging camera 1 in this embodiment is operably connected via a
cable 5 to a video recording device 2.
[0078] The second portion 2 is generally "U shaped" with the leg
portions of the "U" being sufficiently spaced apart to accommodate
a human torso. The second portion 8 can function to support at
least part of the thermal imaging camera 1 and at least part of the
digital video camera 2. The second portion 8 is configured to
receive the shoulder portions of a human. The term configured to
receive the shoulder portion of the human torso means that the
second portion 8 rests on the shoulder so that the harness is above
the shoulders. In one embodiment, the residential inspection
devices are attached to the second portion. The first portion 7 and
second portion 8 are configured to support at least one residential
inspection device in that they provide a flat, rigid platform for
the residential inspection devices. The second portion 8 can
include a plurality of handles 4 which project generally
downwardly. The plurality of handles 4 may be of any shape to be
gripped by the hand of the person wearing the harness apparatus 3.
The second portion 8 can be formed of two parts to make a more
rectangular enclosure (not shown).
[0079] In the alternate embodiment shown in FIG. 3, the harness
apparatus 3 is a generally triangular shaped substantially one
piece unit. In this embodiment, a combination unit thermal imaging
camera recording device 6 is affixed to the first portion 7 of the
harness apparatus 3. The harness apparatus 3 includes a portion 8
adopted to retain the shoulder portion of a human torso. A single
handle 12 can be made one piece with the unit or attached to the
harness apparatus 3.
[0080] The embodiment shown in FIGS. 1 and 2 can include a means to
transmit a digital image to a central receiving facility. This
communication apparatus 13 can be affixed to harness apparatus 3.
Various wireless communication apparatus are known to skilled in
the art, such as a wireless internet communication system.
[0081] Exterior Residential Application--The use of the infrared
equipment for exterior inspection has proved beneficial in cases
where the exterior clad is made of wood and wood product siding,
EIFS, or vinyl siding. The thermal properties of these materials
are such that the infrared camera can discern moisture
infiltration, some structural anomalies, and the occasional insect
infestation. The same can said for inspection of eaves and fascias
utilizing the infrared equipment.
[0082] There are some cautions that the user has to be aware of,
however. First and foremost, if the infrared equipment is being
used outdoors, the current weather conditions should be an obvious
consideration. Precipitation of any kind will damage the
electronics, the digital camera and infrared camera.
[0083] Another consideration is the position of the sun. The
thermal load provided by direct, or indirect, sunlight (also called
solar load) is tremendous and cannot be sated for by the equipment.
Therefore, successful use of the infrared sensor depends on the
time of day and solar position. The user may have to delay or
reschedule use of the infrared equipment on a particular part of
the house that is currently in full sun. Solar loading can,
however, provide opportunities for infrared investigations of
exteriors that ordinarily would not be possible of the equipment on
exterior surfaces depends on access to a thermal window. The
thermal window represents the optimum opportunity for the infrared
camera to discern thermal differences within building components.
The optimal time to catch the thermal window for exterior wall
surfaces are after sunset and after sunrise.
[0084] More specifically, conditions for obtaining a good thermal
window are: sunny day, little to no wind, and clear sky. During the
summer time, a thermal window begins to open around an hour to a
couple of hours after sunset and after sunrise when sun energy
begins to heat up the wall surfaces. In the wintertime a thermal
window may begin to open as early as a few minutes after sunset and
right after sunrise, depending on where you are. The colder the
location is, the faster the thermal window will open.
[0085] Thermal capacity is the physical property of a material's
ability to store energy. The materials in a wall assembly have
relatively low thermal capacitances when compared to water. Water
requires a lot of energy to raise its temperature and likewise must
release a lot of energy to cool down. Therefore, moisture in a
finished exterior wall will appear as cold spot during the after
sunrise thermal window period on the other hand it will appear as
warm spot during the after sunset thermal window. This phenomenal
provides us a very useful way of inspecting moisture within
finished exterior wall such as various type of siding (steel,
vinyl, etc.), stucco, Exterior Insulation Finish System (EIFS).
However, it should be noted that a thermal window exists when there
is a differential temperature between building components. This can
occur if one of the components includes moisture or if one of the
components is being differentially heated by the sun.
[0086] Thermal window for inspecting within either finished
exterior wall, interior wall or exterior roof overhang (eaves) can
also be obtained when moisture allowed to evaporate. In order for
water molecule to evaporate it must absorb heat energy from its
surrounding as a result the moisture spot appear as cold spot. When
the thermal window opens, the operator will be able to see more and
more visual definition of the thermal differences within building
components and its components. This means that as the window opens,
the internal components of a wall's structure will become more and
more pronounced as displayed on the video screen of the equipment,
leading to better resolution and increased accuracy of the
inspection.
[0087] More specifically, this process relates to an inspection of
an exterior residential building component. The exterior
residential building component is selected from the group
consisting of: wall, fascia and eave. The process of obtaining a
temperature profile of an outside residential component implies
that a thermal window exists, in that, a useful temperature profile
could not be obtained without thermal differences between
components. The next step involves obtaining a temperature profile
of the exterior residential building components. Then, a
temperature profile is recorded on a digital recording device. The
digital recording is reviewed to detect any thermal anomalies. Now
referring to FIG. 4A, an EFIS exterior wall is shown with a regular
video photograph. In FIG. 4B, a temperature profile, taken in the
morning after sunrise when the thermal window has just began to
open shows a warm spot 15 which is indicative of moisture within an
EFIS wall.
[0088] In FIGS. 5A and 5B, temperature profiles, taken when
moisture is allowed to evaporate shows anomalies as dark spots 21
and 23 under the vinyl siding. This moisture is not visible to the
human eye. These anomalies 21 and 23 are indicative of the presence
of moisture under the vinyl siding.
[0089] Now referring to FIG. 6, a temperature profile, taken in the
morning after sunrise of an eave shows a number of anomalies.
Anomaly 24 and 25 are indicative of current structural deformations
due to past infiltration of water (dried) and anomaly 26 is
indicative of the presence of moisture.
[0090] FIG. 7 shows a temperature profile taken in the morning of a
dry EIFS wall showing no thermal anomalies.
[0091] FIGS. 8 and 9 show temperature profile taken at noon. In
FIG. 8, no thermal anomalies are present, while in FIG. 9, a
thermal anomaly 28 shows a cracked brick wall. This temperature
profile shows as a thermal anomaly because moisture is in the crack
in the wall.
[0092] Roofs (Pitched Roof) Applications--In the heat of the day,
the thermal load on a roof can be quite striking to view through an
infrared detector. Anomalies show up as dark shadows against a
bright background. More specifically, referring to FIGS. 10A and
10B, thermal anomalies 29 and 30 are shown as dark spots. This type
of thermal anomaly is indicative of water damage to a roof. These
types of thermal anomalies are present for two to three days after
rain. This period is considered the thermal window for this
application. In the present method, a pitched roof is defined as a
roof having a slope ranging greater than a rise of 1 by 12
inches.
[0093] A pitched roof is inspected by obtaining a temperature
profile of the interior surface of the pitched roof from inside of
the attic within three days of rain. This method using an infrared
camera coupled to a digital camera can provide information on
active water leaks prior to the leaks being visible. Water damage
to a roof as seen from interior of the attic space is revealed as
dark shadows against the normally bright roof decking. When
conducting this method, additional confirmation can be obtained by
observing: (a) water below the stain or interior staining or water
damage on finished surfaces; or presence of moisture confirmed from
results of moisture meter test; or (c) visible damage to the
decking such as: presence of a dark stain coupled with positive
moisture meter reading; or presence of visible active growths of
mold or mildew; or decking delamination; or decking discoloration;
or combinations of the above.
[0094] This invention can be applied to pitched roofs to inspect
the condition of a residential roof. More specifically, in the
source of a leak can be traced by assessing the thermal anomaly 31.
The leak can be followed from left to right to find the leak shown
as the dark spot. Additionally, this method can also be used to
detect structural deformation. The thermal anomaly shown as the
white irregular spot 14 is indicative of a puncture in the roof
material with the shingles covering over the puncture. This method
can also be used to detect structural damage such as cracks. The
temperature profile is corded on a digital recording device.
[0095] Electrical Applications--Many problems in the electrical
systems are the result of abnormal heating associated with high
resistance or excessive current flow. Thermal imaging scan
(Infrared thermography) allows us to see these invisible thermal
patterns before damage occurs. A thermal imaging scan allows an
inspector to quickly locate the suspicious electrical hot spots
from among the hundreds and thousands of potential problems. The
primary benefit of inspecting residential building electrical
system is to increase safety.
[0096] When electricity (electrical current) flows through a
circuit, part of the electrical current is converted into heat
energy. This is due to the normal electrical resistance in the
circuit. High resistance has been used to produce heat or light to
make our life more comfortable. However, in many instances, heat is
an unwanted by-product that results in energy lost, costly damage,
and hazarded condition. For example, when resistance is unusually
high due to an over fuse under size conductor, loose connection,
rusted connection, defective switch, the circuit may become hot.
Electrical components can become hot enough to melt the electrical
insulation and result in a house fire.
[0097] There here are two major categories of electrical hot spots:
surface over heat and overload. 1. Contact surface over heat--This
type of problem occurred when electrical current flow through a
single point of contact with high resistance. They usually
associated with rusted or warned out switch contact. The same
problem can also occurred to electrical connector. 2.
Overload--This type of problem occurred when high amount of current
flow through a circuit. They usually associated with over fuse
under size conductors.
[0098] Infrared detection provides another level of inspection for
the electrical service throughout the house. This method to detect
a potential overload of an electrical circuit in a residential
building includes turning on substantially all light switches and
exhaust blowers in a residential building. Next, a temperature
profile is obtained of each electrical outlet in the residential
building. The temperature profile is assessed for a thermal
anomaly. If a thermal anomaly is detected, the next step can be to
determine compliance with safety electrical guidelines.
[0099] Safety Electrical Guidelines: (1) make sure no over fuse
(over breaker); (2) make sure proper grounding; (3) make sure no
hot neutral reverse; (4) make sure no open ground; (5) make sure
all other electrical safety installation procedures are followed
(such as aluminum wire, and GFCI.
[0100] The purpose of turning on substantially all of the light
switches and substantially all of the exhaust blowers is to allow
current to flow through the normal electrical loads while the
inspector performs the exterior inspection. If a few light switches
or blowers are missed, this still constitutes "substantially all".
The order of which is turned on first is not important between the
light switches and the exhaust blowers. During the time the
inspector is inspecting the exterior portion of the house, the
electrical system in the house has the opportunity to heat up under
normal load. If an electrical circuit is drawing substantial amount
of current that the circuit can't support, or in the case of faulty
connections or faulty switches, the circuit will heat up and can
provide a thermal signature indicating a potential problem with
that particular circuit.
[0101] GFCI outlets and dimmer switch controls will always show a
light heat signature in excess of surrounding materials because the
GFCI outlet has an active circuit in operation at all times to test
for electrical leakage. The dimmer switches are rheostats that
adjust current flow to things like chandeliers, fans, etc. Since
the current is adjustable, under maximum load the dimmer switch
will also develop a heat signature in excess of that of the
surrounding materials. Do not construe these normal heat signatures
to mean that an inspector should not evaluate each dimmer switch or
GFCI outlet. On the contrary, the inspector should take time to
determine if the temperature differential is unusually high for
each of the above. If the dimmer switch or switch plate cover is
hot to the touch or 30 degrees F. higher than the surrounding wall
temperature, further investigation is warranted. The same is true
of a GFCI that is unusually warm or hot to the touch.
[0102] Referring to FIGS. 11, 12, 13A and 13B, various temperature
profiles of electrical components are shown. These temperature
profiles are made as part of a process to detect a potential
problem with an electrical circuit of a residential building. In
this method, the first step is to turn on substantially all of the
light switches in the residential building. Then, a temperature
profile, such as those shown in FIGS. 11, 12, 13A and 13B is
obtained. Each of the temperature profiles is assessed for an
anomaly. For example, FIG. 11 shows an on/off switch 13 and a GFCI
outlet 32 that are normal. FIG. 12 is a temperature profile of a
dimmer switcher that shows an anomaly 33 indicative of a very hot
dimmer switch. Similarly, FIGS. 13A and 13B show thermal anomalies
34-39 indicative of heavily leaded electrical circuits. FIG. 13CE
show a thermal anomaly indicative of a hot electrical wire. When a
thermal anomaly is detected, the next step, in the preferred
embodiment, is to direct the designated entity to with a licensed
electrician.
[0103] Interior Residential Applications--The interior building
components of a residence can be thermally scanned. The interior
building component includes: wall insulation, plumbing, structural
members and air ducts.
[0104] The inspector should turn on the heating/air conditioning by
setting the interior thermostat(s) to 10.degree. F. above or below
the ambient exterior temperature shortly after arrival on site.
When outdoor temperature is above 70.degree. F., turn on the air
conditioner to 10.degree. F. lower. When outdoor temperature is
less than 70.degree. F., turn on the heat to 10.degree. F. higher.
This provides two of the three major requirements to obtain a
suitable thermal gradient within a house: 1) increasing temperature
differential between finished surfaces and interior ambient air
temperature, and 2) interior air movement throughout the living
spaces of the home. The temperature differential provides the
gradient. The moving air enhances the gradient and sharpens the
contrast between hidden moisture within structures and substrates
and other areas within the structures or substrate, permitting the
thermal camera to visually illustrate those thermal
differences.
[0105] Referring to FIGS. 14A, 14B and 14C, a method to scan an
interior residential building component is disclosed. In the first
step of this scanning method, an operator using the imaging camera
1, digital recording device 2 and harness apparatus 3 shown in FIG.
1 scans from afar as shown in FIG. 14A. Next, the operator scans
from midrange pointing the imaging camera from two equidistant
points in a room as shown in FIG. 14B. In the next step, as shown
in FIG. 14C, a scan from close range is accomplished by scanning a
plurality of points within a smaller arc. Different inspectors may
have a different way of scanning the interior of the building;
however, any method adopted should be systematic to insure
completeness. The combination of the use of the harness apparatus
3, the use of a systematic method to scan and the use of the
methods to improve image contrast result in a rapid method to
nondestructively inspect a residence.
[0106] When assessing the temperature profile, it is important for
the inspector to confirm the dark spots are not due to: (1)
improper setting of the infrared camera; (2) cold air from HVAC or
cold outside air; (3) water pipes; (4) knots of wood; and (5)
improper installation of insulation. [0107] a. Insulation--Infrared
wall inspection can some time be confusing due to various reasons.
The following discussion provides a basis to review thermal scans
conducted in different seasons.
[0108] Now referring to FIG. 15, 2.times.4 studs and ceiling
rafters appear as cold in a well-insulated wall during the winter
season. This is due to the fact that insulation is a relatively
poor heat conductor as compared to 2.times.4 wood stud ceiling
rafters, as a result, 2.times.4 wood stud ceiling rafters lose
relatively more heat than the insulation from indoor to
outdoor).
[0109] Now referring to FIGS. 16 and 17, 2.times.4 studs 40 and 41
appear as warm in uninsulated or very poorly insulated wall (left
half of the wall) during the winter season. This is due to the fact
that 2.times.4 wood stud now is a relatively better insulator as
compare to uninsulated air space, as a result the 2.times.4 stud
looses relatively less heat than the uninsulated air space (from
the indoor to the outdoor). The right portion 42 and 43 appears to
be insulated from this temperature profile.
[0110] Now referring to FIG. 18, 2.times.4 studs appear as warm in
a well-insulated wall during the summer season. This is due to the
fact that 2.times.4 wood stud is a relatively good heat conductor
as compare to insulation between studs; as a result, 2.times.4
studs conducts more out door heat than the insulated wall
section.
[0111] Now referring to FIG. 19, 2.times.4 studs appear as cold in
uninsulated or very poorly insulated wall during the summer season.
This is due to the fact that the 2.times.4 studs now is a
relatively better insulator as compare to uninsulated or poorly
insulated air space, as a result 2.times.4 now conducts relatively
less outdoor heat than the uninsulated or very poorly insulated
wall section. The wall and ceiling of a residential building can be
inspected to determine if they are uninsulated using this method.
FIGS. 16, 17 and 19, show temperature profiles indicative of
uninsulated interior building components.
[0112] (2) Plumbing--Hidden plumbing leaks can pinpoint within
finished surfaces utilizing the thermal camera in cases where
visual inspection was not possible. In FIG. 20A, a temperature
profile is obtained for plumbing fixtures after the thermal window
is created. The term plumbing fixture can include the plumbing
fixture itself or associated piping. The temperature profile is
recorded on a digital recording device and reviewed for a thermal
anomaly. The temperature profile shown in FIG. 20A shows anomalies
44 and 45, which are indicative of a moisture leak behind the wall.
FIG. 20B shows an air conditioning duct with a darker portion 46
indicative of cold air. The temperature profile of FIG. 20B is a
normal profile for an air conditioning duct.
[0113] (3) Condensation--Poorly managed moisture in a building can
cause considerable damage that is often concealed for some time.
Moisture in vapor form in the air causes no harm to building.
However, when this moisture condenses to liquid form at the wrong
place, damage can occur. The tricky part is, this often happens in
areas that are difficult or impossible to see (within wall cavity)
or difficult to determine the cause behind the problem. In the
event of water leakage in a building, as the water begins to
evaporate it produces a colder area, which can also be easily
registered by the infrared sensor (camera).
[0114] In the wintertime the air in an average house at 70.degree.
F. and 40% relative humidity will be saturated and will condense to
water droplets when the temperature drops to 45.degree. F. It is
not too difficult to understand how indoor air leaking into a wall
or attic space will cool quickly. The outside of your walls and
underside of the roof in your attic space is much closer to the
outdoor temperature. When this bundle of warm moist indoor air
leaks out through the wall or ceiling, it will cool and condense in
the wall or ceiling/roof.
[0115] Condensation can also occur on interior ceiling surface as
shown in FIGS. 21A and 21B. The temperature profile shown in FIG.
21A was shown in FIG. 21A was taken 4 feet away from the ceiling.
The anomaly 47 is indicative of moisture on the ceiling. The
temperature profile 21B was taken 15 feet away from the same
ceiling shown in FIG. 21A. The anomaly 48 is indicative of moisture
in the ceiling.
[0116] (4) Moisture in Air Duct--Additionally, FIGS. 21C and 21D
show anomalies 49-51, which are indicative of moisture in an air
duct. This happens most often when there is no insulation in that
particular section of the ceiling due to poor workmanship or due to
rodent activities plus the occupant of the house has the lifestyle
of generating high level of moisture with inadequate ventilation
during the winter season. The uninsulated ceiling is closer to the
cold outdoor temperature. When the high level moisture indoor air
come in contact with the cold interior ceiling surface (the hotter
the air the higher it rises and more moisture it can hold), it will
cool and condense. This type of condensation problems were often
mistaken as roof leaks. This happens when there is insufficient
insulation around the air duct and poor workmanship or aging
insulation Condensation accumulates in cold air (in summer)
eventually dripping into the ceiling under the duct.
[0117] (5) Mold--Condensation in building can cause mold. Building
materials that remain wet for between 24 to 48 hours have the
potential for mold developing and developing quickly. Molds thrive
on organic material and eventually eat away at the material.
Cellulose material such as ceiling tile, dry wall, insulation,
books, carpeting, upholstered furniture, curtains, food and etc.
Remediation of mold: The most important thing is to find the source
of causing the mold to grow, which is the moisture. A good mold
investigator focuses on locating moisture not microbiology or
sampling. Condensation, construction techniques, and water
intrusion lie at the heart of a proper mold investigation. Mold
issues begin and end with moisture issues--Caoimhin P. Connell
(Senior Industrial Hygienist for Colorado industrial hygiene and
toxicological consulting firm). The method for inspection of
interior residential components can be applied to locate the source
of moisture. The source of the moisture can be correlated with mold
growth.
[0118] There is a limit to how much moisture can be stored. Wood is
able to safely store up to 20% moisture by weight. Moisture levels
above this can cause rot, mold and mildew. The preset method can be
used to locate moisture and correlate this moisture with mold
growth.
[0119] (6) Small Animal--As for small animals, such as mice, rats,
squirrels, and etc. when they infest a house attic or wall space,
they tend to burrow through insulation, creating air gaps in the
normally evenly distributed insulation and thereby changing the
thermal properties of the insulation, leaving visual evidence of
tunnels and nests that would normally be invisible to even the
trained eye. FIGS. 22 and 23 are thermal profiles of an interior
component of a residential building. A review of a digital
recording of this thermal profile shows an anomaly that is
interpreted as tunnels in insulation in the ceiling (FIG. 22) a
tunnel in the insulation in the walls (FIG. 23).
[0120] (7) Misalignment or Damage--In the case of less than perfect
construction techniques, the trained observer can spot missing,
misaligned or damaged internal structural members such as studs,
headers, trimmers and the like. In some cases, those damaged or
missing members may contribute to otherwise unaccounted for
interior that would normally point to foundation troubles, but
which are, in fact, framing problems. FIGS. 24 and 25 are
temperature profiles of interior components of a residential
building. In FIG. 24, the thermal anomaly 52 is indicative of a
structural misalignment. In FIG. 25, the thermal anomaly 53 is
indicative of a structural misalignment. A review of the digital
recording of the thermal profile shows an anomaly this is
indicative of structure misalignment.
[0121] (8) Wood Destroying Insect--Pests such as termites and even
mouse and rat infestations have been recorded because of the
telltale thermal discrepancies their respective environments
provide. In the case of native termite species, these destructive
pests require moisture in order to survive at high humidity levels.
The thermal imaging system provides an additional tool for
discovering the presence of termites and increases the detection of
an active colony from about 30% (traditional inspection method) to
at least 60%. This means that while the sensor system cannot detect
100% of all termite infestations, it can measurably double the
chances of finding active colonies that have not been discovered
through traditional inspection. FIGS. 26 and 27 are thermal
profiles indicative of suspected termite infestation. More
specifically, FIG. 26 shows to thermal anomalies 54 and 55,
indicative of suspicious wood destroying insect infestation.
Similarly, FIG. 27 shows an anomaly 56 indicative of wood
destroying insect infestation. The presence of wood destroying
insects can be confirmed by an acoustic scan. The protocol for an
acoustic scan is set out in U.S. Ser. No. 10/680,377 filed Oct. 7,
2003.
[0122] (9) Duct Leakage--FIGS. 28 and 29 show a temperature profile
indicative of air duct leakage. In these temperature profiles, the
anomalies 57, 58, 59 are indicative of air leaking out of an air
duct. The black is cold air leakage in the summer (in the winter it
would be opposite).
[0123] (10) Inspection of basement wall (water leaks through
cracks, pipes, etc.) The application of the present thermal imaging
techniques provides the ability to distinguish areas of relative
temperature difference. This means that cool areas appear dark
relative to warmer areas, which appear lighter. Relative
temperature can be seen under these conditions. The first is
different thermal characteristics of the building components, the
second is actual differences in temperature, and the third is the
ability of heat to be removed from the substrate by evaporation.
The mere presence of moisture within or exterior to a building
component does not guarantee that the thermal camera will show that
moisture is present. There has to be a way for evaporation to
permit heat loss. Without the ability to evaporate, water will take
on the temperature of the substrate, and the equipment will be
blind to the presence of the moisture. It should be recalled in
order for the camera to distinguish relative differences in
temperature, there has to exist a temperature difference of
0.08.degree. C. or greater between residential building
components.
[0124] Thus, to inspect a basement, if it is necessary, to create
air flow to the basement area by: (a) Open heating or cooling air
outlet if they are closed (wait for at least 30 Minutes before
infrared; (b) Open all basement doors or windows (wait for at least
30 minutes before Infrared scan); and (c) Create artificial air
flow by using portable force air heater (wait for at least 30
minutes before infrared scan).
[0125] FIGS. 30 and 31 are temperature profiles indicative of
moisture penetrating through cracks in a basement wall. More
specifically, in FIGS. 30 and 31, anomalies 60 and 61 are
indicative of moisture on a basement wall.
[0126] The temperature profiles database library is made of a
compilation of numerous temperature profiles in different settings,
areas and conditions over a period of this regard, the system may
be used as an experimental setup to capture recordings of
temperature profiles that can be used as reference patterns for
comparison with future captured temperature profile patterns. The
temperature profiles database library can also be used as a
valuable training tool for training future inspectors. This
invention also provides a method for facilitating a computerized
method for inspection of a residential building. This method
involves maintaining a database of temperature profiles for
residential building components at a computerized, centralized
facility. The temperature profiles can be input to the computer via
a wireless transmission means such as wireless internet connection
or by a nonwireless transmission means, such as a disk, a cable and
infrared transmission.
[0127] An application database management program, such as SAP or
Oracle, can be used to set up fields, such as, type anomaly, normal
residential building component, residential building component with
an anomaly, and a specific designated residential building. The
fields are used to facilitate scanning the database for a selected
temperature profile. Thus, if one is interested in, for example, a
specific residential building, all temperature profiles relating to
a specific house are selected. For example, a specific residential
structure can be inspected on a periodic basis, and the temperature
profiles can be maintained in a field in the database. These
inspections can occur on different days such as three times a year.
A printer driver on the hard drive of the computer is used to
control a printing device to print a report showing selected
temperature profiles of residential building components.
[0128] Although the present invention has been described and
illustrated with respect to preferred embodiments and a preferred
use thereof, it is not to be so limited since modifications and
changes can be made therein which are within the full scope of the
invention.
* * * * *