The type of
thermographic survey that is needed depends upon a project's specific needs.
The majority of thermographic surveys help locate air leakage paths, and to
identify thermal anomalies (a result of poorly installed or missing thermal
insulation). All thermographic surveys are of a non-destructive and non-contact
nature, which means that there will not be any damage to the property being surveyed.
The majority
of thermographic surveys undertaken by Air Pressure Testing are typically carried
out in conjunction with one of our building air-tightness tests. Whilst the
house is depressurised, cold air from the outside will be drawn in through gaps
in the structure. Where there is a temperature differential, the effect of any
infiltration will be seen by the thermal imaging camera during the
thermographic test. This type of thermographic survey is usually carried out
from the inside of a property, and is not usually dependent upon particular
weather conditions (as for other surveys). Once the leakage path areas are
identified, the necessary remedial sealing works can be carried out by the air
leakage company prior to the thermographic survey
Thermographic
surveys are also carried out to find defects in thermal insulation and other
areas of construction defects that represent a heating energy loss. This type
of thermographic survey is usually carried out both internally and externally.
External thermographic surveys require the correct weather conditions and are
generally carried out in the hours of darkness.
The thermographic
survey method and the environmental conditions required to enable a
satisfactory interpretation of the thermal images in relation to insulation are
described in ISO 6781: Thermal insulation - Qualitative detection of thermal
irregularities in building envelopes - Infrared method. For most
investigations the requirements are as follows:
·
A temperature difference between
the inside and outside of a house of at least 5°C over a period of four or more
hours, allowing the building mass to be heated. Because of this, best thermographic
results are often (although not always) obtained in the heating season (October
to March).
·
Diffused light - i.e. minimal
sunlight, again for a period of four or more hours, otherwise the solar
temperature gain emitted from the surface of a structure could be interpreted
as an energy loss.
·
Dry conditions during the thermographic
survey. This is not necessarily to protect the equipment, but because any rain
on the surface of a building will cool the temperature, potentially leading to
inaccurate interpretation of the thermal image during the thermographic survey.
·
Low wind speeds (less than 6m/s
or light to moderate breeze)
Typically, results will be presented as a series of radiometric images (or
thermograms) which will physically illustrate areas of heat loss from the
building surfaces. Usually the thermograms are presented with the range of
surface temperatures measured, and a normal visual image for ease of reference.
Potential faults located by the thermographic survey will be marked on the
images contained in the thermographic report. These faults can also be added to
layout and elevation drawings of the building. A report will provide a
professional interpretation of thermograms, and a complete record of the thermographic
survey, listing the equipment used, and the environmental conditions at the
time of the thermographic survey.
General Notes
All components
of a building emit infrared radiation - heat that
is invisible to the human eye. The infrared (thermographic) camera observes
this infrared radiation and displays an image of the thermal patterns
electronically during the thermographic survey.
Air Pressure Testing’s
Technicians skilled and qualified in building diagnostics can establish from these image which elements have surface heat patterns that
signify conductive or convective heat loss/gain.
In building
thermography, thermographic surveys tend to be qualitative rather than
quantitative. In practice we are seeking comparative areas that exhibit
disparate characteristics or thermal patterns, under the same conditions, during
the Thermographic test as a means of identification and highlighting areas that
require further investigation, remedial attention, or indeed, confirming that a
previous fault has been rectified.
An infrared (thermographic)
survey may require support by referring to construction drawings, moisture
meters, humidity and temperature data-logging, anemometers, barometers, blower doors and smoke pencils, or
larger smoke machines
A
"quantitative" thermal investigation (thermographic testing) may also
help determine the magnitude of an anomaly, by taking temperature readings from
the recorded images.
Moisture
and Mould
Extraneous moisture in building fabrics may compromise
structural integrity and create an ideal environment for mould growth and
insect infestations. Infra Red cameras differentiate between wet and dry
materials by exploiting the thermal characteristic of wet materials to store
heat very well and warm up or cool down more slowly than dry materials. The
growing number of health-related legal actions based upon adverse human health
reactions to mould and bacteria is a growing concern for lenders, developers,
facilities managers, and building owners and investors. Let Air Pressure
Testing alleviate these problems by undertaking a Thermographic survey
To
remedy problems caused by mould
the primary task is to rapidly and accurately locate and remove all sources of
moisture and identify the point of ingress. Infra Red cameras can instantly
image complete rooms, inspect areas that can’t be surveyed with moisture
meters, reveal wet conditions/areas behind surfaces such as enameled walls and
wallpaper that don’t readily water stain, track leaks to their source, monitor
the drying process, and confirm when a structure is dry. Let Air Pressure
Testing find these areas now by undertaking a Thermographic survey
Construction Defects
The current
trend for using
external thermal and structural insulation facade systems, along with stone,
stucco, brick veneers and siding as facades on residential as well as commercial buildings invites the possibility of
water ingress if the quality of installation is faulty. Thermographic surveys can detect or
verify moisture infiltration in these weatherproofing “barrier” systems, which
are usually caused by insufficient detailing such as inadequate or improperly
applied flashing or sealants. Without an Thermographic survey the cause of many
“mystery” leaks and the detection of moisture migration paths within the walls,
floors and ceilings are virtually impossible to find Air pressure testing will
help you find these leaks using the latest Thermographic equipment.
Roof Leaks
Roof leaks can cause costly damage to a
building’s structural integrity, it’s plant and
contents. A Thermographic inspection can quickly pinpoint missing or moisture -
laden insulation under a flat roof membrane where the insulation needs
replacement, permitting the surgical repair of failed areas rather than the
much more costly replacement of the entire roof.
Roofing
Thermographic survey / inspection is best conducted after sunset, since
the wet areas retain the heat absorbed during the day longer than the
surrounding dry areas, causing a temperature difference that can be imaged,
with the wet areas showing up as hot spots. The Thermographic inspections can
also be used to inspect roof decks from inside a building, a highly effective
approach when working with metal and ballasted roofing systems, which are
difficult or impossible to inspect from above. In this case, the inspection and
then Thermographic survey can be performed shortly
after sunrise, when the wet areas of the underside of the roof warm up more
slowly than dry areas and show up as cold spots. Using Infrared
Thermographic survey cameras, capable of recognising temperature differences
down to 0.1 °C. using a Thermographic survey such
anomalies are easily recorded for future remedial works.
Post-disaster
Inspections
Post
–disaster inspections
using Infrared
cameras & Thermographic surveys can be an invaluable method of rapidly
identifying remnant hot spots, assuring that the fire is totally extinguished
and providing invaluable data for insurance assessors with their Cause and
Origin investigations. The clear Infra Red Thermographic survey images of
normally invisible diagnostic evidence can assist in the planning and execution
of the restoration programme and in the settlement process. After flooding, Infra
Red Thermographic surveys can rapidly define the degree of water damage and
enhance the drying process by rendering the wet portion of materials visible.
Historic / Listed Buildings
Apart from the obvious and established use of locating and
defining heat loss (which in itself can be very important in an old building)
applications for infra red Thermographic surveys include the location and/or
assessment of the following:
·
Structural timber frames behind render, weather-boarding
plaster etc.
·
Structural joints, infilled openings etc. behind render on
masonry walls
·
Bond failure and moisture ingress in renders, pargetting and
harling
·
Lintels, structural failures, snapped headers etc. in brickwork
·
Variations in moisture levels
Assessment
and inspection by
conventional means can often involve the hire of expensive access equipment,
temporary scaffolding and disruption of activity. Infrared Thermographic survey
Assessment
and inspection by conventional
means can often involve the hire of expensive access equipment, temporary
scaffolding and disruption of activity. Infrared surveys however can often be
conducted from ground level. The speed with which an entire street can be
assessed by undertaking a Thermographic survey makes it a valuable tool in
historical recording. The Thermographic survey images can be electronically
captured, stored on disc and printed out in colour. However, infra-red
Thermographic surveys is very sensitive to climatic conditions - rain or bright
sun on a wall to be investigated may prevent any successful Thermographic assessment,
and the temperature gradient required sometimes means that more information on
heated buildings can be obtained in winter, and unheated ones (such as
churches) may be better having the Thermographic survey at night when the day's
solar gain provides sufficient gradation.
Air leak /
Heat Loss
A significant contribution to heat loss in a building can be caused by poor levels of air
tightness/air leakage . The economic consequences can
be increased fuel bills and system running costs caused by heating systems
having to work harder than necessary to keep the building at a satisfactory
temperature. Relatively minor air leakages in a building can lead to draughts
and discomfort for householders, patches of condensation on walls and
inefficient energy performance. Identifying the source of a draught can be
difficult with the air leakage paths often hidden by kitchen units, bath panels
or other boarding.
Air Leakage testing uses a fan system to depressurise the building. The system
is fitted into a frame sealed within an external opening such as a doorframe.
Mechanical ventilation openings are sealed with polythene sheet and tape or
other appropriate materials. Smoke extract fans/vents are closed but not
sealed, and other internal openings (e.g. lift shafts) are left unsealed. As
the building is depressurised, colder air is drawn into the building through
gaps, crack and holes in the building fabric. These may be visually noted,
identified by the use of smoke pencils or recorded on a thermographic survey image.
Combining a blower door test with thermography surveys in this way, enables a
systematic recording, with visual evidence in the form of thermograms and
photographs, of air leakage paths, which can be combined with annotated floor
plans in a Thermographic
survey report if required.
Sound / Noise
Leakage
Noise
leaks can be
difficult to locate. As noise tends to follow the same path as an air leak – a leak
the size of a keyhole will reduce the sound insulation properties of a wall by
10dB – the same method of blower door and
thermography /Thermographic surveys can be utilized to track down the cause of
noise leaks between rooms or floors.
News Letter for Contractors
Has it gone
amiss? Are the implications understood? Professionals in a number of related
disciplines may not know of its function, but since September 2001 thermography/
Thermographic surveys has sat quietly within Part L2 of the building
regulations.
Look closely and the references will be found under ‘section 2.1b’. At the time
of publication, the technology and techniques required to ascertain the
continuity of insulation/thermal bridging within a building-envelope, were just
emerging. Whilst the objectives of such an inspection were readily agreed, the
methodology and practicality, in terms of cost / benefit, had yet to be
developed.
Most industries are adverse to change and the construction world is no
different. Tighter building regulations require a stronger more advanced design
and build technique, which in turn necessitates higher standards of inspection,
quality audits and product approval.
This is why thermography/ Thermographic survey are becoming an integral part of
the overall process, as it can provide the documentary evidence to prove
compliance.
So
what is thermography?
Thermography is a method by which thermal information of an object can be
acquired, processed and then displayed in a visual way with the data recorded
within the Thermographic surveys remedial works can easily be undertaken. A
‘thermogram’ or ‘thermal image’ can be likened to a picture created with heat,
in the same way that a photograph is a picture created with light. All objects
warmer than –273° C emit infrared radiation. The power and wavelength of the
emission varies with the temperature such that colder objects emit less
infrared energy, this becomes easily recognisable when shown as part of a
Thermographic survey.
The small additional cost for building handovers including thermography /
thermographic surveys is minimal, especially if compared to the expenditure on
energy bills during the life cycle of a structure. Controlling the heat loss
leads to an immediate financial benefit for the consumer whilst reducing carbon
emission and the conservation of fuel and power.
A thermographic
building survey not nly shows continuity of insulation but in areas of prolific
heat loss can aid with the development of future design details. The importance
of this tool will inevitably grow as the general understanding and acceptance
spreads; but that’s for the future.
Only professionally qualified thermographic companies or individuals should
conduct thermographic building surveys.
The report delivered should include:
·
Reference
to building drawings/plans
·
Camera
serial number, time and date of survey
·
Environmental
Conditions of Survey
·
Locations
of where the still IR images were collected
·
Qualitative
infrared and digital video showing all buildings external elevations
·
Report
pages detailing any specific observed anomalies with analysis
·
Date,
signature, calibration certificate of Camera and Thermographers certification number.
For further information on thermography building inspections
please contact Air Pressure Testing, who will be more than willing to assist
with any of your questions or queries.
The type of
thermographic survey that is needed depends upon a project's specific needs.
The majority of thermographic surveys help locate air leakage paths, and to
identify thermal anomalies (a result of poorly installed or missing thermal
insulation). All thermographic surveys are of a non-destructive and non-contact
nature, which means that there will not be any damage to the property being
surveyed.
The majority
of thermographic surveys undertaken by Air Pressure Testing are typically
carried out in conjunction with one of our building air-tightness tests. Whilst
the house is depressurised, cold air from the outside will be drawn in through
gaps in the structure. Where there is a temperature differential, the effect of
any infiltration will be seen by the thermal imaging camera during the
thermographic test. This type of thermographic survey is usually carried out
from the inside of a property, and is not usually dependent upon particular
weather conditions (as for other surveys). Once the leakage path areas are
identified, the necessary remedial sealing works can be carried out by the air
leakage company prior to the thermographic survey
Thermographic
surveys are also carried out to find defects in thermal insulation and other
areas of construction defects that represent a heating energy loss. This type
of thermographic survey is usually carried out both internally and externally.
External thermographic surveys require the correct weather conditions and are
generally carried out in the hours of darkness.
The
thermographic survey method and the environmental conditions required to enable
a satisfactory interpretation of the thermal images in relation to insulation
are described in ISO 6781: Thermal insulation - Qualitative detection of thermal
irregularities in building envelopes - Infrared method. For most
investigations the requirements are as follows:
·
A temperature difference between
the inside and outside of a house of at least 5°C over a period of four or more
hours, allowing the building mass to be heated. Because of this, best
thermographic results are often (although not always) obtained in the heating
season (October to March).
·
Diffused light - i.e. minimal
sunlight, again for a period of four or more hours, otherwise the solar
temperature gain emitted from the surface of a structure could be interpreted
as an energy loss.
·
Dry conditions during the
thermographic survey. This is not necessarily to protect the equipment, but
because any rain on the surface of a building will cool the temperature,
potentially leading to inaccurate interpretation of the thermal image during
the thermographic survey.
·
Low wind speeds (less than 6m/s
or light to moderate breeze)
Typically, results will be presented as a series of radiometric images (or
thermograms) which will physically illustrate areas of heat loss from the
building surfaces. Usually the thermograms are presented with the range of
surface temperatures measured, and a normal visual image for ease of reference.
Potential faults located by the thermographic survey will be marked on the
images contained in the thermographic report. These faults can also be added to
layout and elevation drawings of the building. A report will provide a
professional interpretation of thermograms, and a complete record of the thermographic
survey, listing the equipment used, and the environmental conditions at the
time of the thermographic survey.
General Notes
All components
of a building emit infrared radiation - heat that
is invisible to the human eye. The infrared (thermographic) camera observes
this infrared radiation and displays an image of the thermal patterns
electronically during the thermographic survey.
Air Pressure
Testing’s Technicians skilled and qualified in building diagnostics can
establish from these image which elements have surface
heat patterns that signify conductive or convective heat loss/gain.
In building
thermography, thermographic surveys tend to be qualitative rather than
quantitative. In practice we are seeking comparative areas that exhibit
disparate characteristics or thermal patterns, under the same conditions, during
the Thermographic test as a means of identification and highlighting areas that
require further investigation, remedial attention, or indeed, confirming that a
previous fault has been rectified.
An infrared (thermographic)
survey may require support by referring to construction drawings, moisture
meters, humidity and temperature data-logging, anemometers, barometers, blower doors and smoke pencils, or
larger smoke machines
A
"quantitative" thermal investigation (thermographic testing) may also
help determine the magnitude of an anomaly, by taking temperature readings from
the recorded images.
Moisture
and Mould
Extraneous moisture in building fabrics may compromise
structural integrity and create an ideal environment for mould growth and
insect infestations. Infra Red cameras differentiate between wet and dry
materials by exploiting the thermal characteristic of wet materials to store
heat very well and warm up or cool down more slowly than dry materials. The
growing number of health-related legal actions based upon adverse human health
reactions to mould and bacteria is a growing concern for lenders, developers,
facilities managers, and building owners and investors. Let Air Pressure
Testing alleviate these problems by undertaking a Thermographic survey
To
remedy problems caused by mould
the primary task is to rapidly and accurately locate and remove all sources of
moisture and identify the point of ingress. Infra Red cameras can instantly
image complete rooms, inspect areas that can’t be surveyed with moisture
meters, reveal wet conditions/areas behind surfaces such as enameled walls and
wallpaper that don’t readily water stain, track leaks to their source, monitor
the drying process, and confirm when a structure is dry. Let Air Pressure
Testing find these areas now by undertaking a Thermographic survey
Construction Defects
The current
trend for using
external thermal and structural insulation facade systems, along with stone,
stucco, brick veneers and siding as facades on residential as well as commercial buildings invites the possibility of
water ingress if the quality of installation is faulty. Thermographic surveys can detect or verify moisture infiltration in
these weatherproofing “barrier” systems, which are usually caused by
insufficient detailing such as inadequate or improperly applied flashing or
sealants. Without an Thermographic survey the cause of many “mystery” leaks and
the detection of moisture migration paths within the walls, floors and ceilings
are virtually impossible to find Air pressure testing will help you find these
leaks using the latest Thermographic equipment.
Roof Leaks
Roof leaks can cause costly damage to a
building’s structural integrity, it’s plant and contents. A Thermographic inspection
can quickly pinpoint missing or moisture - laden insulation under a flat roof
membrane where the insulation needs replacement, permitting the surgical repair
of failed areas rather than the much more costly replacement of the entire
roof.
Roofing
Thermographic survey / inspection is best conducted after sunset, since
the wet areas retain the heat absorbed during the day longer than the
surrounding dry areas, causing a temperature difference that can be imaged, with
the wet areas showing up as hot spots. The Thermographic inspections can also
be used to inspect roof decks from inside a building, a highly effective
approach when working with metal and ballasted roofing systems, which are
difficult or impossible to inspect from above. In this case, the inspection and
then Thermographic survey can be performed shortly after sunrise, when the wet
areas of the underside of the roof warm up more slowly than dry areas and show
up as cold spots. Using Infrared Thermographic survey cameras, capable of
recognising temperature differences down to 0.1 °C. using a Thermographic
survey such anomalies are easily recorded for future remedial works.
Post-disaster
Inspections
Post
–disaster inspections
using Infrared
cameras & Thermographic surveys can be an invaluable method of rapidly
identifying remnant hot spots, assuring that the fire is totally extinguished
and providing invaluable data for insurance assessors with their Cause and
Origin investigations. The clear Infra Red Thermographic survey images of
normally invisible diagnostic evidence can assist in the planning and execution
of the restoration programme and in the settlement process. After flooding, Infra
Red Thermographic surveys can rapidly define the degree of water damage and
enhance the drying process by rendering the wet portion of materials visible.
Historic / Listed Buildings
Apart from the obvious and established use of locating and
defining heat loss (which in itself can be very important in an old building)
applications for infra red Thermographic surveys include the location and/or
assessment of the following:
·
Structural timber frames behind render, weather-boarding
plaster etc.
·
Structural joints, infilled openings etc. behind render on
masonry walls
·
Bond failure and moisture ingress in renders, pargetting and
harling
·
Lintels, structural failures, snapped headers etc. in
brickwork
·
Variations in moisture levels
Assessment
and inspection by
conventional means can often involve the hire of expensive access equipment,
temporary scaffolding and disruption of activity. Infrared Thermographic survey
Assessment
and inspection by
conventional means can often involve the hire of expensive access equipment,
temporary scaffolding and disruption of activity. Infrared surveys however can
often be conducted from ground level. The speed with which an entire street can
be assessed by undertaking a Thermographic survey makes it a valuable tool in
historical recording. The Thermographic survey images can be electronically
captured, stored on disc and printed out in colour. However, infra-red
Thermographic surveys is very sensitive to climatic conditions - rain or bright
sun on a wall to be investigated may prevent any successful Thermographic assessment,
and the temperature gradient required sometimes means that more information on
heated buildings can be obtained in winter, and unheated ones (such as
churches) may be better having the Thermographic survey at night when the day's
solar gain provides sufficient gradation.
Air leak /
Heat Loss
A significant contribution to heat loss in a building can be caused by poor levels of
air tightness/air leakage . The economic consequences can be increased fuel
bills and system running costs caused by heating systems having to work harder than
necessary to keep the building at a satisfactory temperature. Relatively minor
air leakages in a building can lead to draughts and discomfort for
householders, patches of condensation on walls and inefficient energy
performance. Identifying the source of a draught can be difficult with the air
leakage paths often hidden by kitchen units, bath panels or other boarding.
Air Leakage testing uses a fan system to depressurise the building. The system
is fitted into a frame sealed within an external opening such as a doorframe.
Mechanical ventilation openings are sealed with polythene sheet and tape or
other appropriate materials. Smoke extract fans/vents are closed but not
sealed, and other internal openings (e.g. lift shafts) are left unsealed. As
the building is depressurised, colder air is drawn into the building through
gaps, crack and holes in the building fabric. These may be visually noted,
identified by the use of smoke pencils or recorded on a thermographic survey image.
Combining a blower door test with thermography surveys in this way, enables a
systematic recording, with visual evidence in the form of thermograms and
photographs, of air leakage paths, which can be combined with annotated floor
plans in a Thermographic
survey report if required.
Sound / Noise
Leakage
Noise
leaks can be
difficult to locate. As noise tends to follow the same path as an air leak – a
leak the size of a keyhole will reduce the sound insulation properties of a
wall by 10dB – the same method of blower door and
thermography /Thermographic surveys can be utilized to track down the cause of
noise leaks between rooms or floors.
News Letter for Contractors
Has it gone
amiss? Are the implications understood? Professionals in a number of related
disciplines may not know of its function, but since September 2001 thermography/
Thermographic surveys has sat quietly within Part L2 of the building
regulations.
Look closely and the references will be found under ‘section 2.1b’. At the time
of publication, the technology and techniques required to ascertain the
continuity of insulation/thermal bridging within a building-envelope, were just
emerging. Whilst the objectives of such an inspection were readily agreed, the
methodology and practicality, in terms of cost / benefit, had yet to be
developed.
Most industries are adverse to change and the construction world is no
different. Tighter building regulations require a stronger more advanced design
and build technique, which in turn necessitates higher standards of inspection,
quality audits and product approval.
This is why thermography/ Thermographic survey are becoming an integral part of
the overall process, as it can provide the documentary evidence to prove
compliance.
So
what is thermography?
Thermography is a method by which thermal information of an object can be
acquired, processed and then displayed in a visual way with the data recorded
within the Thermographic surveys remedial works can easily be undertaken. A
‘thermogram’ or ‘thermal image’ can be likened to a picture created with heat,
in the same way that a photograph is a picture created with light. All objects
warmer than –273° C emit infrared radiation. The power and wavelength of the
emission varies with the temperature such that colder objects emit less
infrared energy, this becomes easily recognisable when shown as part of a
Thermographic survey.
The small additional cost for building handovers including thermography / thermographic
surveys is minimal, especially if compared to the expenditure on energy bills
during the life cycle of a structure. Controlling the heat loss leads to an
immediate financial benefit for the consumer whilst reducing carbon emission
and the conservation of fuel and power.
A thermographic
building survey not nly shows continuity of insulation but in areas of prolific
heat loss can aid with the development of future design details. The importance
of this tool will inevitably grow as the general understanding and acceptance
spreads; but that’s for the future.
Only professionally qualified thermographic companies or individuals should
conduct thermographic building surveys.
The report delivered should include:
·
Reference
to building drawings/plans
·
Camera
serial number, time and date of survey
·
Environmental
Conditions of Survey
·
Locations
of where the still IR images were collected
·
Qualitative
infrared and digital video showing all buildings external elevations
·
Report
pages detailing any specific observed anomalies with analysis
·
Date,
signature, calibration certificate of Camera and Thermographers certification
number.
For further information on thermography building inspections
please contact Air Pressure Testing, who will be more than willing to assist
with any of your questions or queries.
The type of
thermographic survey that is needed depends upon a project's specific needs.
The majority of thermographic surveys help locate air leakage paths, and to
identify thermal anomalies (a result of poorly installed or missing thermal
insulation). All thermographic surveys are of a non-destructive and non-contact
nature, which means that there will not be any damage to the property being
surveyed.
The majority
of thermographic surveys undertaken by Air Pressure Testing are typically
carried out in conjunction with one of our building air-tightness tests. Whilst
the house is depressurised, cold air from the outside will be drawn in through
gaps in the structure. Where there is a temperature differential, the effect of
any infiltration will be seen by the thermal imaging camera during the
thermographic test. This type of thermographic survey is usually carried out
from the inside of a property, and is not usually dependent upon particular
weather conditions (as for other surveys). Once the leakage path areas are
identified, the necessary remedial sealing works can be carried out by the air
leakage company prior to the thermographic survey
Thermographic
surveys are also carried out to find defects in thermal insulation and other
areas of construction defects that represent a heating energy loss. This type
of thermographic survey is usually carried out both internally and externally.
External thermographic surveys require the correct weather conditions and are
generally carried out in the hours of darkness.
The
thermographic survey method and the environmental conditions required to enable
a satisfactory interpretation of the thermal images in relation to insulation are
described in ISO 6781: Thermal insulation - Qualitative detection of thermal
irregularities in building envelopes - Infrared method. For most
investigations the requirements are as follows:
·
A temperature difference between
the inside and outside of a house of at least 5°C over a period of four or more
hours, allowing the building mass to be heated. Because of this, best
thermographic results are often (although not always) obtained in the heating
season (October to March).
·
Diffused light - i.e. minimal
sunlight, again for a period of four or more hours, otherwise the solar
temperature gain emitted from the surface of a structure could be interpreted
as an energy loss.
·
Dry conditions during the
thermographic survey. This is not necessarily to protect the equipment, but
because any rain on the surface of a building will cool the temperature,
potentially leading to inaccurate interpretation of the thermal image during
the thermographic survey.
·
Low wind speeds (less than 6m/s
or light to moderate breeze)
Typically, results will be presented as a series of radiometric images (or
thermograms) which will physically illustrate areas of heat loss from the
building surfaces. Usually the thermograms are presented with the range of
surface temperatures measured, and a normal visual image for ease of reference.
Potential faults located by the thermographic survey will be marked on the
images contained in the thermographic report. These faults can also be added to
layout and elevation drawings of the building. A report will provide a
professional interpretation of thermograms, and a complete record of the thermographic
survey, listing the equipment used, and the environmental conditions at the
time of the thermographic survey.
General Notes
All components
of a building emit infrared radiation - heat that
is invisible to the human eye. The infrared (thermographic) camera observes
this infrared radiation and displays an image of the thermal patterns
electronically during the thermographic survey.
Air Pressure
Testing’s Technicians skilled and qualified in building diagnostics can
establish from these image which elements have surface heat patterns that signify
conductive or convective heat loss/gain.
In building
thermography, thermographic surveys tend to be qualitative rather than
quantitative. In practice we are seeking comparative areas that exhibit
disparate characteristics or thermal patterns, under the same conditions, during
the Thermographic test as a means of identification and highlighting areas that
require further investigation, remedial attention, or indeed, confirming that a
previous fault has been rectified.
An infrared (thermographic)
survey may require support by referring to construction drawings, moisture
meters, humidity and temperature data-logging, anemometers, barometers, blower doors and smoke pencils, or
larger smoke machines
A
"quantitative" thermal investigation (thermographic testing) may also
help determine the magnitude of an anomaly, by taking temperature readings from
the recorded images.
Moisture
and Mould
Extraneous moisture in building fabrics may compromise
structural integrity and create an ideal environment for mould growth and
insect infestations. Infra Red cameras differentiate between wet and dry
materials by exploiting the thermal characteristic of wet materials to store
heat very well and warm up or cool down more slowly than dry materials. The
growing number of health-related legal actions based upon adverse human health
reactions to mould and bacteria is a growing concern for lenders, developers,
facilities managers, and building owners and investors. Let Air Pressure
Testing alleviate these problems by undertaking a Thermographic survey
To
remedy problems caused by mould
the primary task is to rapidly and accurately locate and remove all sources of
moisture and identify the point of ingress. Infra Red cameras can instantly
image complete rooms, inspect areas that can’t be surveyed with moisture
meters, reveal wet conditions/areas behind surfaces such as enameled walls and
wallpaper that don’t readily water stain, track leaks to their source, monitor
the drying process, and confirm when a structure is dry. Let Air Pressure
Testing find these areas now by undertaking a Thermographic survey
Construction Defects
The current
trend for using
external thermal and structural insulation facade systems, along with stone,
stucco, brick veneers and siding as facades on residential as well as commercial buildings invites the possibility of
water ingress if the quality of installation is faulty. Thermographic surveys can detect or verify moisture infiltration in
these weatherproofing “barrier” systems, which are usually caused by
insufficient detailing such as inadequate or improperly applied flashing or sealants.
Without an Thermographic survey the cause of many “mystery” leaks and the
detection of moisture migration paths within the walls, floors and ceilings are
virtually impossible to find Air pressure testing will help you find these
leaks using the latest Thermographic equipment.
Roof Leaks
Roof leaks can cause costly damage to a
building’s structural integrity, it’s plant and contents. A Thermographic inspection
can quickly pinpoint missing or moisture - laden insulation under a flat roof
membrane where the insulation needs replacement, permitting the surgical repair
of failed areas rather than the much more costly replacement of the entire
roof.
Roofing
Thermographic survey / inspection is best conducted after sunset, since
the wet areas retain the heat absorbed during the day longer than the
surrounding dry areas, causing a temperature difference that can be imaged,
with the wet areas showing up as hot spots. The Thermographic inspections can
also be used to inspect roof decks from inside a building, a highly effective
approach when working with metal and ballasted roofing systems, which are
difficult or impossible to inspect from above. In this case, the inspection and
then Thermographic survey can be performed shortly after sunrise, when the wet
areas of the underside of the roof warm up more slowly than dry areas and show
up as cold spots. Using Infrared Thermographic survey cameras, capable of
recognising temperature differences down to 0.1 °C. using a Thermographic
survey such anomalies are easily recorded for future remedial works.
Post-disaster
Inspections
Post
–disaster inspections
using Infrared
cameras & Thermographic surveys can be an invaluable method of rapidly
identifying remnant hot spots, assuring that the fire is totally extinguished and
providing invaluable data for insurance assessors with their Cause and Origin
investigations. The clear Infra Red Thermographic survey images of normally
invisible diagnostic evidence can assist in the planning and execution of the
restoration programme and in the settlement process. After flooding, Infra Red
Thermographic surveys can rapidly define the degree of water damage and enhance
the drying process by rendering the wet portion of materials visible.
Historic / Listed Buildings
Apart from the obvious and established use of locating and
defining heat loss (which in itself can be very important in an old building)
applications for infra red Thermographic surveys include the location and/or
assessment of the following:
·
Structural timber frames behind render, weather-boarding
plaster etc.
·
Structural joints, infilled openings etc. behind render on
masonry walls
·
Bond failure and moisture ingress in renders, pargetting and
harling
·
Lintels, structural failures, snapped headers etc. in
brickwork
·
Variations in moisture levels
Assessment
and inspection by
conventional means can often involve the hire of expensive access equipment,
temporary scaffolding and disruption of activity. Infrared Thermographic survey
Assessment
and inspection by
conventional means can often involve the hire of expensive access equipment,
temporary scaffolding and disruption of activity. Infrared surveys however can
often be conducted from ground level. The speed with which an entire street can
be assessed by undertaking a Thermographic survey makes it a valuable tool in
historical recording. The Thermographic survey images can be electronically
captured, stored on disc and printed out in colour. However, infra-red
Thermographic surveys is very sensitive to climatic conditions - rain or bright
sun on a wall to be investigated may prevent any successful Thermographic assessment,
and the temperature gradient required sometimes means that more information on
heated buildings can be obtained in winter, and unheated ones (such as
churches) may be better having the Thermographic survey at night when the day's
solar gain provides sufficient gradation.
Air leak /
Heat Loss
A significant contribution to heat loss in a building can be caused by poor levels of
air tightness/air leakage . The economic consequences can be increased fuel
bills and system running costs caused by heating systems having to work harder
than necessary to keep the building at a satisfactory temperature. Relatively
minor air leakages in a building can lead to draughts and discomfort for
householders, patches of condensation on walls and inefficient energy
performance. Identifying the source of a draught can be difficult with the air
leakage paths often hidden by kitchen units, bath panels or other boarding.
Air Leakage testing uses a fan system to depressurise the building. The system
is fitted into a frame sealed within an external opening such as a doorframe.
Mechanical ventilation openings are sealed with polythene sheet and tape or
other appropriate materials. Smoke extract fans/vents are closed but not
sealed, and other internal openings (e.g. lift shafts) are left unsealed. As
the building is depressurised, colder air is drawn into the building through
gaps, crack and holes in the building fabric. These may be visually noted,
identified by the use of smoke pencils or recorded on a thermographic survey image.
Combining a blower door test with thermography surveys in this way, enables a
systematic recording, with visual evidence in the form of thermograms and
photographs, of air leakage paths, which can be combined with annotated floor
plans in a Thermographic
survey report if required.
Sound / Noise
Leakage
Noise
leaks can be
difficult to locate. As noise tends to follow the same path as an air leak – a
leak the size of a keyhole will reduce the sound insulation properties of a
wall by 10dB – the same method of blower door and
thermography /Thermographic surveys can be utilized to track down the cause of
noise leaks between rooms or floors.
News Letter for Contractors
Has it gone
amiss? Are the implications understood? Professionals in a number of related
disciplines may not know of its function, but since September 2001 thermography/
Thermographic surveys has sat quietly within Part L2 of the building
regulations.
Look closely and the references will be found under ‘section 2.1b’. At the time
of publication, the technology and techniques required to ascertain the
continuity of insulation/thermal bridging within a building-envelope, were just
emerging. Whilst the objectives of such an inspection were readily agreed, the
methodology and practicality, in terms of cost / benefit, had yet to be
developed.
Most industries are adverse to change and the construction world is no
different. Tighter building regulations require a stronger more advanced design
and build technique, which in turn necessitates higher standards of inspection,
quality audits and product approval.
This is why thermography/ Thermographic survey are becoming an integral part of
the overall process, as it can provide the documentary evidence to prove
compliance.
So
what is thermography?
Thermography is a method by which thermal information of an object can be acquired,
processed and then displayed in a visual way with the data recorded within the
Thermographic surveys remedial works can easily be undertaken. A ‘thermogram’
or ‘thermal image’ can be likened to a picture created with heat, in the same
way that a photograph is a picture created with light. All objects warmer than
–273° C emit infrared radiation. The power and wavelength of the emission
varies with the temperature such that colder objects emit less infrared energy,
this becomes easily recognisable when shown as part of a Thermographic survey.
The small additional cost for building handovers including thermography /
thermographic surveys is minimal, especially if compared to the expenditure on
energy bills during the life cycle of a structure. Controlling the heat loss
leads to an immediate financial benefit for the consumer whilst reducing carbon
emission and the conservation of fuel and power.
A thermographic
building survey not nly shows continuity of insulation but in areas of prolific
heat loss can aid with the development of future design details. The importance
of this tool will inevitably grow as the general understanding and acceptance
spreads; but that’s for the future.
Only professionally qualified thermographic companies or individuals should
conduct thermographic building surveys.
The report delivered should include:
·
Reference
to building drawings/plans
·
Camera
serial number, time and date of survey
·
Environmental
Conditions of Survey
·
Locations
of where the still IR images were collected
·
Qualitative
infrared and digital video showing all buildings external elevations
·
Report
pages detailing any specific observed anomalies with analysis
·
Date,
signature, calibration certificate of Camera and Thermographers certification
number.
For further information on thermography building inspections
please contact Air Pressure Testing, who will be more than willing to assist
with any of your questions or queries.
The type of
thermographic survey that is needed depends upon a project's specific needs.
The majority of thermographic surveys help locate air leakage paths, and to
identify thermal anomalies (a result of poorly installed or missing thermal
insulation). All thermographic surveys are of a non-destructive and non-contact
nature, which means that there will not be any damage to the property being
surveyed.
The majority
of thermographic surveys undertaken by Air Pressure Testing are typically
carried out in conjunction with one of our building air-tightness tests. Whilst
the house is depressurised, cold air from the outside will be drawn in through
gaps in the structure. Where there is a temperature differential, the effect of
any infiltration will be seen by the thermal imaging camera during the thermographic
test. This type of thermographic survey is usually carried out from the inside
of a property, and is not usually dependent upon particular weather conditions
(as for other surveys). Once the leakage path areas are identified, the
necessary remedial sealing works can be carried out by the air leakage company
prior to the thermographic survey
Thermographic
surveys are also carried out to find defects in thermal insulation and other
areas of construction defects that represent a heating energy loss. This type
of thermographic survey is usually carried out both internally and externally.
External thermographic surveys require the correct weather conditions and are
generally carried out in the hours of darkness.
The
thermographic survey method and the environmental conditions required to enable
a satisfactory interpretation of the thermal images in relation to insulation
are described in ISO 6781: Thermal insulation - Qualitative detection of thermal
irregularities in building envelopes - Infrared method. For most
investigations the requirements are as follows:
·
A temperature difference between
the inside and outside of a house of at least 5°C over a period of four or more
hours, allowing the building mass to be heated. Because of this, best
thermographic results are often (although not always) obtained in the heating
season (October to March).
·
Diffused light - i.e. minimal
sunlight, again for a period of four or more hours, otherwise the solar
temperature gain emitted from the surface of a structure could be interpreted
as an energy loss.
·
Dry conditions during the
thermographic survey. This is not necessarily to protect the equipment, but
because any rain on the surface of a building will cool the temperature,
potentially leading to inaccurate interpretation of the thermal image during
the thermographic survey.
·
Low wind speeds (less than 6m/s
or light to moderate breeze)
Typically, results will be presented as a series of radiometric images (or
thermograms) which will physically illustrate areas of heat loss from the
building surfaces. Usually the thermograms are presented with the range of
surface temperatures measured, and a normal visual image for ease of reference.
Potential faults located by the thermographic survey will be marked on the
images contained in the thermographic report. These faults can also be added to
layout and elevation drawings of the building. A report will provide a
professional interpretation of thermograms, and a complete record of the thermographic
survey, listing the equipment used, and the environmental conditions at the
time of the thermographic survey.
General Notes
All components
of a building emit infrared radiation - heat that
is invisible to the human eye. The infrared (thermographic) camera observes
this infrared radiation and displays an image of the thermal patterns
electronically during the thermographic survey.
Air Pressure
Testing’s Technicians skilled and qualified in building diagnostics can
establish from these image which elements have surface heat patterns that
signify conductive or convective heat loss/gain.
In building
thermography, thermographic surveys tend to be qualitative rather than quantitative.
In practice we are seeking comparative areas that exhibit disparate
characteristics or thermal patterns, under the same conditions, during the
Thermographic test as a means of identification and highlighting areas that
require further investigation, remedial attention, or indeed, confirming that a
previous fault has been rectified.
An infrared (thermographic)
survey may require support by referring to construction drawings, moisture
meters, humidity and temperature data-logging, anemometers, barometers, blower doors and smoke pencils, or
larger smoke machines
A
"quantitative" thermal investigation (thermographic testing) may also
help determine the magnitude of an anomaly, by taking temperature readings from
the recorded images.
Moisture
and Mould
Extraneous moisture in building fabrics may compromise
structural integrity and create an ideal environment for mould growth and
insect infestations. Infra Red cameras differentiate between wet and dry
materials by exploiting the thermal characteristic of wet materials to store
heat very well and warm up or cool down more slowly than dry materials. The
growing number of health-related legal actions based upon adverse human health
reactions to mould and bacteria is a growing concern for lenders, developers,
facilities managers, and building owners and investors. Let Air Pressure
Testing alleviate these problems by undertaking a Thermographic survey
To
remedy problems caused by mould
the primary task is to rapidly and accurately locate and remove all sources of
moisture and identify the point of ingress. Infra Red cameras can instantly
image complete rooms, inspect areas that can’t be surveyed with moisture
meters, reveal wet conditions/areas behind surfaces such as enameled walls and
wallpaper that don’t readily water stain, track leaks to their source, monitor
the drying process, and confirm when a structure is dry. Let Air Pressure
Testing find these areas now by undertaking a Thermographic survey
Construction Defects
The current
trend for using
external thermal and structural insulation facade systems, along with stone,
stucco, brick veneers and siding as facades on residential as well as commercial buildings invites the possibility of
water ingress if the quality of installation is faulty. Thermographic surveys can detect or verify moisture infiltration in
these weatherproofing “barrier” systems, which are usually caused by
insufficient detailing such as inadequate or improperly applied flashing or
sealants. Without an Thermographic survey the cause of many “mystery” leaks and
the detection of moisture migration paths within the walls, floors and ceilings
are virtually impossible to find Air pressure testing will help you find these
leaks using the latest Thermographic equipment.
Roof Leaks
Roof leaks can cause costly damage to a
building’s structural integrity, it’s plant and contents. A Thermographic inspection
can quickly pinpoint missing or moisture - laden insulation under a flat roof
membrane where the insulation needs replacement, permitting the surgical repair
of failed areas rather than the much more costly replacement of the entire
roof.
Roofing
Thermographic survey / inspection is best conducted after sunset, since
the wet areas retain the heat absorbed during the day longer than the
surrounding dry areas, causing a temperature difference that can be imaged,
with the wet areas showing up as hot spots. The Thermographic inspections can
also be used to inspect roof decks from inside a building, a highly effective
approach when working with metal and ballasted roofing systems, which are
difficult or impossible to inspect from above. In this case, the inspection and
then Thermographic survey can be performed shortly after sunrise, when the wet
areas of the underside of the roof warm up more slowly than dry areas and show
up as cold spots. Using Infrared Thermographic survey cameras, capable of
recognising temperature differences down to 0.1 °C. using a Thermographic
survey such anomalies are easily recorded for future remedial works.
Post-disaster
Inspections
Post
–disaster inspections
using Infrared
cameras & Thermographic surveys can be an invaluable method of rapidly
identifying remnant hot spots, assuring that the fire is totally extinguished
and providing invaluable data for insurance assessors with their Cause and
Origin investigations. The clear Infra Red Thermographic survey images of
normally invisible diagnostic evidence can assist in the planning and execution
of the restoration programme and in the settlement process. After flooding, Infra
Red Thermographic surveys can rapidly define the degree of water damage and
enhance the drying process by rendering the wet portion of materials visible.
Historic / Listed Buildings
Apart from the obvious and established use of locating and
defining heat loss (which in itself can be very important in an old building)
applications for infra red Thermographic surveys include the location and/or
assessment of the following:
·
Structural timber frames behind render, weather-boarding
plaster etc.
·
Structural joints, infilled openings etc. behind render on
masonry walls
·
Bond failure and moisture ingress in renders, pargetting and
harling
·
Lintels, structural failures, snapped headers etc. in
brickwork
·
Variations in moisture levels
Assessment
and inspection by
conventional means can often involve the hire of expensive access equipment,
temporary scaffolding and disruption of activity. Infrared Thermographic survey
Assessment
and inspection by
conventional means can often involve the hire of expensive access equipment,
temporary scaffolding and disruption of activity. Infrared surveys however can
often be conducted from ground level. The speed with which an entire street can
be assessed by undertaking a Thermographic survey makes it a valuable tool in
historical recording. The Thermographic survey images can be electronically
captured, stored on disc and printed out in colour. However, infra-red
Thermographic surveys is very sensitive to climatic conditions - rain or bright
sun on a wall to be investigated may prevent any successful Thermographic assessment,
and the temperature gradient required sometimes means that more information on
heated buildings can be obtained in winter, and unheated ones (such as
churches) may be better having the Thermographic survey at night when the day's
solar gain provides sufficient gradation.
Air leak /
Heat Loss
A significant contribution to heat loss in a building can be caused by poor levels of
air tightness/air leakage . The economic consequences can be increased fuel
bills and system running costs caused by heating systems having to work harder
than necessary to keep the building at a satisfactory temperature. Relatively
minor air leakages in a building can lead to draughts and discomfort for
householders, patches of condensation on walls and inefficient energy
performance. Identifying the source of a draught can be difficult with the air
leakage paths often hidden by kitchen units, bath panels or other boarding.
Air Leakage testing uses a fan system to depressurise the building. The system
is fitted into a frame sealed within an external opening such as a doorframe.
Mechanical ventilation openings are sealed with polythene sheet and tape or
other appropriate materials. Smoke extract fans/vents are closed but not
sealed, and other internal openings (e.g. lift shafts) are left unsealed. As
the building is depressurised, colder air is drawn into the building through
gaps, crack and holes in the building fabric. These may be visually noted,
identified by the use of smoke pencils or recorded on a thermographic survey image.
Combining a blower door test with thermography surveys in this way, enables a
systematic recording, with visual evidence in the form of thermograms and
photographs, of air leakage paths, which can be combined with annotated floor
plans in a Thermographic
survey report if required.
Sound / Noise
Leakage
Noise
leaks can be
difficult to locate. As noise tends to follow the same path as an air leak – a
leak the size of a keyhole will reduce the sound insulation properties of a
wall by 10dB – the same method of blower door and
thermography /Thermographic surveys can be utilized to track down the cause of
noise leaks between rooms or floors.
News Letter for Contractors
Has it gone
amiss? Are the implications understood? Professionals in a number of related
disciplines may not know of its function, but since September 2001 thermography/
Thermographic surveys has sat quietly within Part L2 of the building
regulations.
Look closely and the references will be found under ‘section 2.1b’. At the time
of publication, the technology and techniques required to ascertain the
continuity of insulation/thermal bridging within a building-envelope, were just
emerging. Whilst the objectives of such an inspection were readily agreed, the
methodology and practicality, in terms of cost / benefit, had yet to be
developed.
Most industries are adverse to change and the construction world is no
different. Tighter building regulations require a stronger more advanced design
and build technique, which in turn necessitates higher standards of inspection,
quality audits and product approval.
This is why thermography/ Thermographic survey are becoming an integral part of
the overall process, as it can provide the documentary evidence to prove
compliance.
So
what is thermography?
Thermography is a method by which thermal information of an object can be
acquired, processed and then displayed in a visual way with the data recorded
within the Thermographic surveys remedial works can easily be undertaken. A
‘thermogram’ or ‘thermal image’ can be likened to a picture created with heat,
in the same way that a photograph is a picture created with light. All objects
warmer than –273° C emit infrared radiation. The power and wavelength of the
emission varies with the temperature such that colder objects emit less
infrared energy, this becomes easily recognisable when shown as part of a
Thermographic survey.
The small additional cost for building handovers including thermography /
thermographic surveys is minimal, especially if compared to the expenditure on
energy bills during the life cycle of a structure. Controlling the heat loss
leads to an immediate financial benefit for the consumer whilst reducing carbon
emission and the conservation of fuel and power.
A thermographic
building survey not nly shows continuity of insulation but in areas of prolific
heat loss can aid with the development of future design details. The importance
of this tool will inevitably grow as the general understanding and acceptance
spreads; but that’s for the future.
Only professionally qualified thermographic companies or individuals should
conduct thermographic building surveys.
The report delivered should include:
·
Reference
to building drawings/plans
·
Camera
serial number, time and date of survey
·
Environmental
Conditions of Survey
·
Locations
of where the still IR images were collected
·
Qualitative
infrared and digital video showing all buildings external elevations
·
Report
pages detailing any specific observed anomalies with analysis
·
Date,
signature, calibration certificate of Camera and Thermographers certification
number.
For further information on thermography building inspections
please contact Air Pressure Testing, who will be more than willing to assist
with any of your questions or queries.
The type of
thermographic survey that is needed depends upon a project's specific needs.
The majority of thermographic surveys help locate air leakage paths, and to
identify thermal anomalies (a result of poorly installed or missing thermal
insulation). All thermographic surveys are of a non-destructive and non-contact
nature, which means that there will not be any damage to the property being
surveyed.
The majority
of thermographic surveys undertaken by Air Pressure Testing are typically
carried out in conjunction with one of our building air-tightness tests. Whilst
the house is depressurised, cold air from the outside will be drawn in through
gaps in the structure. Where there is a temperature differential, the effect of
any infiltration will be seen by the thermal imaging camera during the
thermographic test. This type of thermographic survey is usually carried out
from the inside of a property, and is not usually dependent upon particular
weather conditions (as for other surveys). Once the leakage path areas are
identified, the necessary remedial sealing works can be carried out by the air
leakage company prior to the thermographic survey
Thermographic
surveys are also carried out to find defects in thermal insulation and other
areas of construction defects that represent a heating energy loss. This type
of thermographic survey is usually carried out both internally and externally.
External thermographic surveys require the correct weather conditions and are
generally carried out in the hours of darkness.
The
thermographic survey method and the environmental conditions required to enable
a satisfactory interpretation of the thermal images in relation to insulation
are described in ISO 6781: Thermal insulation - Qualitative detection of thermal
irregularities in building envelopes - Infrared method. For most
investigations the requirements are as follows:
·
A temperature difference between
the inside and outside of a house of at least 5°C over a period of four or more
hours, allowing the building mass to be heated. Because of this, best
thermographic results are often (although not always) obtained in the heating
season (October to March).
·
Diffused light - i.e. minimal
sunlight, again for a period of four or more hours, otherwise the solar
temperature gain emitted from the surface of a structure could be interpreted
as an energy loss.
·
Dry conditions during the
thermographic survey. This is not necessarily to protect the equipment, but
because any rain on the surface of a building will cool the temperature,
potentially leading to inaccurate interpretation of the thermal image during
the thermographic survey.
·
Low wind speeds (less than 6m/s
or light to moderate breeze)
Typically, results will be presented as a series of radiometric images (or
thermograms) which will physically illustrate areas of heat loss from the
building surfaces. Usually the thermograms are presented with the range of
surface temperatures measured, and a normal visual image for ease of reference.
Potential faults located by the thermographic survey will be marked on the
images contained in the thermographic report. These faults can also be added to
layout and elevation drawings of the building. A report will provide a
professional interpretation of thermograms, and a complete record of the thermographic
survey, listing the equipment used, and the environmental conditions at the
time of the thermographic survey.
General Notes
All components
of a building emit infrared radiation - heat that
is invisible to the human eye. The infrared (thermographic) camera observes
this infrared radiation and displays an image of the thermal patterns
electronically during the thermographic survey.
Air Pressure
Testing’s Technicians skilled and qualified in building diagnostics can
establish from these image which elements have surface heat patterns that
signify conductive or convective heat loss/gain.
In building
thermography, thermographic surveys tend to be qualitative rather than
quantitative. In practice we are seeking comparative areas that exhibit
disparate characteristics or thermal patterns, under the same conditions, during
the Thermographic test as a means of identification and highlighting areas that
require further investigation, remedial attention, or indeed, confirming that a
previous fault has been rectified.
An infrared (thermographic)
survey may require support by referring to construction drawings, moisture
meters, humidity and temperature data-logging, anemometers, barometers, blower doors and smoke pencils, or
larger smoke machines
A
"quantitative" thermal investigation (thermographic testing) may also
help determine the magnitude of an anomaly, by taking temperature readings from
the recorded images.
Moisture
and Mould
Extraneous moisture in building fabrics may compromise
structural integrity and create an ideal environment for mould growth and
insect infestations. Infra Red cameras differentiate between wet and dry
materials by exploiting the thermal characteristic of wet materials to store
heat very well and warm up or cool down more slowly than dry materials. The
growing number of health-related legal actions based upon adverse human health
reactions to mould and bacteria is a growing concern for lenders, developers,
facilities managers, and building owners and investors. Let Air Pressure
Testing alleviate these problems by undertaking a Thermographic survey
To
remedy problems caused by mould
the primary task is to rapidly and accurately locate and remove all sources of
moisture and identify the point of ingress. Infra Red cameras can instantly
image complete rooms, inspect areas that can’t be surveyed with moisture
meters, reveal wet conditions/areas behind surfaces such as enameled walls and
wallpaper that don’t readily water stain, track leaks to their source, monitor
the drying process, and confirm when a structure is dry. Let Air Pressure
Testing find these areas now by undertaking a Thermographic survey
Construction Defects
The current
trend for using
external thermal and structural insulation facade systems, along with stone,
stucco, brick veneers and siding as facades on residential as well as commercial buildings invites the possibility of
water ingress if the quality of installation is faulty. Thermographic surveys can detect or verify moisture infiltration in
these weatherproofing “barrier” systems, which are usually caused by
insufficient detailing such as inadequate or improperly applied flashing or
sealants. Without an Thermographic survey the cause of many “mystery” leaks and
the detection of moisture migration paths within the walls, floors and ceilings
are virtually impossible to find Air pressure testing will help you find these
leaks using the latest Thermographic equipment.
Roof Leaks
Roof leaks can cause costly damage to a
building’s structural integrity, it’s plant and contents. A Thermographic inspection
can quickly pinpoint missing or moisture - laden insulation under a flat roof
membrane where the insulation needs replacement, permitting the surgical repair
of failed areas rather than the much more costly replacement of the entire
roof.
Roofing
Thermographic survey / inspection is best conducted after sunset, since
the wet areas retain the heat absorbed during the day longer than the
surrounding dry areas, causing a temperature difference that can be imaged,
with the wet areas showing up as hot spots. The Thermographic inspections can
also be used to inspect roof decks from inside a building, a highly effective
approach when working with metal and ballasted roofing systems, which are
difficult or impossible to inspect from above. In this case, the inspection and
then Thermographic survey can be performed shortly after sunrise, when the wet
areas of the underside of the roof warm up more slowly than dry areas and show
up as cold spots. Using Infrared Thermographic survey cameras, capable of
recognising temperature differences down to 0.1 °C. using a Thermographic
survey such anomalies are easily recorded for future remedial works.
Post-disaster
Inspections
Post
–disaster inspections
using Infrared
cameras & Thermographic surveys can be an invaluable method of rapidly
identifying remnant hot spots, assuring that the fire is totally extinguished
and providing invaluable data for insurance assessors with their Cause and
Origin investigations. The clear Infra Red Thermographic survey images of
normally invisible diagnostic evidence can assist in the planning and execution
of the restoration programme and in the settlement process. After flooding, Infra
Red Thermographic surveys can rapidly define the degree of water damage and
enhance the drying process by rendering the wet portion of materials visible.
Historic / Listed Buildings
Apart from the obvious and established use of locating and
defining heat loss (which in itself can be very important in an old building)
applications for infra red Thermographic surveys include the location and/or
assessment of the following:
·
Structural timber frames behind render, weather-boarding
plaster etc.
·
Structural joints, infilled openings etc. behind render on
masonry walls
·
Bond failure and moisture ingress in renders, pargetting and
harling
·
Lintels, structural failures, snapped headers etc. in
brickwork
·
Variations in moisture levels
Assessment
and inspection by
conventional means can often involve the hire of expensive access equipment,
temporary scaffolding and disruption of activity. Infrared Thermographic survey
Assessment
and inspection by
conventional means can often involve the hire of expensive access equipment,
temporary scaffolding and disruption of activity. Infrared surveys however can
often be conducted from ground level. The speed with which an entire street can
be assessed by undertaking a Thermographic survey makes it a valuable tool in
historical recording. The Thermographic survey images can be electronically
captured, stored on disc and printed out in colour. However, infra-red
Thermographic surveys is very sensitive to climatic conditions - rain or bright
sun on a wall to be investigated may prevent any successful Thermographic assessment,
and the temperature gradient required sometimes means that more information on
heated buildings can be obtained in winter, and unheated ones (such as
churches) may be better having the Thermographic survey at night when the day's
solar gain provides sufficient gradation.
Air leak /
Heat Loss
A significant contribution to heat loss in a building can be caused by poor levels of
air tightness/air leakage . The economic consequences can be increased fuel
bills and system running costs caused by heating systems having to work harder
than necessary to keep the building at a satisfactory temperature. Relatively
minor air leakages in a building can lead to draughts and discomfort for householders,
patches of condensation on walls and inefficient energy performance.
Identifying the source of a draught can be difficult with the air leakage paths
often hidden by kitchen units, bath panels or other boarding.
Air Leakage testing uses a fan system to depressurise the building. The system
is fitted into a frame sealed within an external opening such as a doorframe.
Mechanical ventilation openings are sealed with polythene sheet and tape or
other appropriate materials. Smoke extract fans/vents are closed but not
sealed, and other internal openings (e.g. lift shafts) are left unsealed. As
the building is depressurised, colder air is drawn into the building through
gaps, crack and holes in the building fabric. These may be visually noted,
identified by the use of smoke pencils or recorded on a thermographic survey image.
Combining a blower door test with thermography surveys in this way, enables a
systematic recording, with visual evidence in the form of thermograms and
photographs, of air leakage paths, which can be combined with annotated floor
plans in a Thermographic
survey report if required.
Sound / Noise
Leakage
Noise
leaks can be
difficult to locate. As noise tends to follow the same path as an air leak – a
leak the size of a keyhole will reduce the sound insulation properties of a
wall by 10dB – the same method of blower door and
thermography /Thermographic surveys can be utilized to track down the cause of
noise leaks between rooms or floors.
News Letter for Contractors
Has it gone
amiss? Are the implications understood? Professionals in a number of related
disciplines may not know of its function, but since September 2001 thermography/
Thermographic surveys has sat quietly within Part L2 of the building
regulations.
Look closely and the references will be found under ‘section 2.1b’. At the time
of publication, the technology and techniques required to ascertain the
continuity of insulation/thermal bridging within a building-envelope, were just
emerging. Whilst the objectives of such an inspection were readily agreed, the
methodology and practicality, in terms of cost / benefit, had yet to be
developed.
Most industries are adverse to change and the construction world is no
different. Tighter building regulations require a stronger more advanced design
and build technique, which in turn necessitates higher standards of inspection,
quality audits and product approval.
This is why thermography/ Thermographic survey are becoming an integral part of
the overall process, as it can provide the documentary evidence to prove
compliance.
So
what is thermography?
Thermography is a method by which thermal information of an object can be
acquired, processed and then displayed in a visual way with the data recorded
within the Thermographic surveys remedial works can easily be undertaken. A
‘thermogram’ or ‘thermal image’ can be likened to a picture created with heat,
in the same way that a photograph is a picture created with light. All objects
warmer than –273° C emit infrared radiation. The power and wavelength of the
emission varies with the temperature such that colder objects emit less
infrared energy, this becomes easily recognisable when shown as part of a
Thermographic survey.
The small additional cost for building handovers including thermography /
thermographic surveys is minimal, especially if compared to the expenditure on
energy bills during the life cycle of a structure. Controlling the heat loss leads
to an immediate financial benefit for the consumer whilst reducing carbon
emission and the conservation of fuel and power.
A thermographic
building survey not nly shows continuity of insulation but in areas of prolific
heat loss can aid with the development of future design details. The importance
of this tool will inevitably grow as the general understanding and acceptance
spreads; but that’s for the future.
Only professionally qualified thermographic companies or individuals should
conduct thermographic building surveys.
The report delivered should include:
·
Reference
to building drawings/plans
·
Camera
serial number, time and date of survey
·
Environmental
Conditions of Survey
·
Locations
of where the still IR images were collected
·
Qualitative
infrared and digital video showing all buildings external elevations
·
Report
pages detailing any specific observed anomalies with analysis
·
Date,
signature, calibration certificate of Camera and Thermographers certification
number.
For further information on thermography building inspections
please contact Air Pressure Testing, who will be more than willing to assist
with any of your questions or queries.
The type of
thermographic survey that is needed depends upon a project's specific needs.
The majority of thermographic surveys help locate air leakage paths, and to
identify thermal anomalies (a result of poorly installed or missing thermal
insulation). All thermographic surveys are of a non-destructive and non-contact
nature, which means that there will not be any damage to the property being
surveyed.
The majority
of thermographic surveys undertaken by Air Pressure Testing are typically
carried out in conjunction with one of our building air-tightness tests. Whilst
the house is depressurised, cold air from the outside will be drawn in through
gaps in the structure. Where there is a temperature differential, the effect of
any infiltration will be seen by the thermal imaging camera during the
thermographic test. This type of thermographic survey is usually carried out
from the inside of a property, and is not usually dependent upon particular
weather conditions (as for other surveys). Once the leakage path areas are
identified, the necessary remedial sealing works can be carried out by the air
leakage company prior to the thermographic survey
Thermographic
surveys are also carried out to find defects in thermal insulation and other
areas of construction defects that represent a heating energy loss. This type
of thermographic survey is usually carried out both internally and externally.
External thermographic surveys require the correct weather conditions and are
generally carried out in the hours of darkness.
The
thermographic survey method and the environmental conditions required to enable
a satisfactory interpretation of the thermal images in relation to insulation
are described in ISO 6781: Thermal insulation - Qualitative detection of thermal
irregularities in building envelopes - Infrared method. For most
investigations the requirements are as follows:
·
A temperature difference between
the inside and outside of a house of at least 5°C over a period of four or more
hours, allowing the building mass to be heated. Because of this, best
thermographic results are often (although not always) obtained in the heating
season (October to March).
·
Diffused light - i.e. minimal
sunlight, again for a period of four or more hours, otherwise the solar
temperature gain emitted from the surface of a structure could be interpreted as
an energy loss.
·
Dry conditions during the
thermographic survey. This is not necessarily to protect the equipment, but
because any rain on the surface of a building will cool the temperature,
potentially leading to inaccurate interpretation of the thermal image during
the thermographic survey.
·
Low wind speeds (less than 6m/s
or light to moderate breeze)
Typically, results will be presented as a series of radiometric images (or
thermograms) which will physically illustrate areas of heat loss from the
building surfaces. Usually the thermograms are presented with the range of
surface temperatures measured, and a normal visual image for ease of reference.
Potential faults located by the thermographic survey will be marked on the
images contained in the thermographic report. These faults can also be added to
layout and elevation drawings of the building. A report will provide a
professional interpretation of thermograms, and a complete record of the thermographic
survey, listing the equipment used, and the environmental conditions at the
time of the thermographic survey.
General Notes
All components
of a building emit infrared radiation - heat that
is invisible to the human eye. The infrared (thermographic) camera observes
this infrared radiation and displays an image of the thermal patterns
electronically during the thermographic survey.
Air Pressure
Testing’s Technicians skilled and qualified in building diagnostics can
establish from these image which elements have surface heat patterns that
signify conductive or convective heat loss/gain.
In building
thermography, thermographic surveys tend to be qualitative rather than
quantitative. In practice we are seeking comparative areas that exhibit
disparate characteristics or thermal patterns, under the same conditions, during
the Thermographic test as a means of identification and highlighting areas that
require further investigation, remedial attention, or indeed, confirming that a
previous fault has been rectified.
An infrared (thermographic)
survey may require support by referring to construction drawings, moisture
meters, humidity and temperature data-logging, anemometers, barometers, blower doors and smoke pencils, or
larger smoke machines
A
"quantitative" thermal investigation (thermographic testing) may also
help determine the magnitude of an anomaly, by taking temperature readings from
the recorded images.
Moisture
and Mould
Extraneous moisture in building fabrics may compromise
structural integrity and create an ideal environment for mould growth and
insect infestations. Infra Red cameras differentiate between wet and dry
materials by exploiting the thermal characteristic of wet materials to store
heat very well and warm up or cool down more slowly than dry materials. The
growing number of health-related legal actions based upon adverse human health
reactions to mould and bacteria is a growing concern for lenders, developers,
facilities managers, and building owners and investors. Let Air Pressure
Testing alleviate these problems by undertaking a Thermographic survey
To
remedy problems caused by mould
the primary task is to rapidly and accurately locate and remove all sources of
moisture and identify the point of ingress. Infra Red cameras can instantly
image complete rooms, inspect areas that can’t be surveyed with moisture
meters, reveal wet conditions/areas behind surfaces such as enameled walls and
wallpaper that don’t readily water stain, track leaks to their source, monitor
the drying process, and confirm when a structure is dry. Let Air Pressure
Testing find these areas now by undertaking a Thermographic survey
Construction Defects
The current
trend for using
external thermal and structural insulation facade systems, along with stone,
stucco, brick veneers and siding as facades on residential as well as commercial buildings invites the possibility of
water ingress if the quality of installation is faulty. Thermographic surveys can detect or verify moisture infiltration in
these weatherproofing “barrier” systems, which are usually caused by
insufficient detailing such as inadequate or improperly applied flashing or
sealants. Without an Thermographic survey the cause of many “mystery” leaks and
the detection of moisture migration paths within the walls, floors and ceilings
are virtually impossible to find Air pressure testing will help you find these
leaks using the latest Thermographic equipment.
Roof Leaks
Roof leaks can cause costly damage to a
building’s structural integrity, it’s plant and contents. A Thermographic inspection
can quickly pinpoint missing or moisture - laden insulation under a flat roof
membrane where the insulation needs replacement, permitting the surgical repair
of failed areas rather than the much more costly replacement of the entire
roof.
Roofing
Thermographic survey / inspection is best conducted after sunset, since
the wet areas retain the heat absorbed during the day longer than the
surrounding dry areas, causing a temperature difference that can be imaged,
with the wet areas showing up as hot spots. The Thermographic inspections can
also be used to inspect roof decks from inside a building, a highly effective
approach when working with metal and ballasted roofing systems, which are
difficult or impossible to inspect from above. In this case, the inspection and
then Thermographic survey can be performed shortly after sunrise, when the wet
areas of the underside of the roof warm up more slowly than dry areas and show
up as cold spots. Using Infrared Thermographic survey cameras, capable of recognising
temperature differences down to 0.1 °C. using a Thermographic survey such
anomalies are easily recorded for future remedial works.
Post-disaster
Inspections
Post
–disaster inspections
using Infrared
cameras & Thermographic surveys can be an invaluable method of rapidly
identifying remnant hot spots, assuring that the fire is totally extinguished
and providing invaluable data for insurance assessors with their Cause and
Origin investigations. The clear Infra Red Thermographic survey images of normally
invisible diagnostic evidence can assist in the planning and execution of the
restoration programme and in the settlement process. After flooding, Infra Red
Thermographic surveys can rapidly define the degree of water damage and enhance
the drying process by rendering the wet portion of materials visible.
Historic / Listed Buildings
Apart from the obvious and established use of locating and
defining heat loss (which in itself can be very important in an old building)
applications for infra red Thermographic surveys include the location and/or
assessment of the following:
·
Structural timber frames behind render, weather-boarding
plaster etc.
·
Structural joints, infilled openings etc. behind render on
masonry walls
·
Bond failure and moisture ingress in renders, pargetting and
harling
·
Lintels, structural failures, snapped headers etc. in
brickwork
·
Variations in moisture levels
Assessment
and inspection by
conventional means can often involve the hire of expensive access equipment,
temporary scaffolding and disruption of activity. Infrared Thermographic survey
Assessment
and inspection by
conventional means can often involve the hire of expensive access equipment,
temporary scaffolding and disruption of activity. Infrared surveys however can
often be conducted from ground level. The speed with which an entire street can
be assessed by undertaking a Thermographic survey makes it a valuable tool in
historical recording. The Thermographic survey images can be electronically
captured, stored on disc and printed out in colour. However, infra-red
Thermographic surveys is very sensitive to climatic conditions - rain or bright
sun on a wall to be investigated may prevent any successful Thermographic assessment,
and the temperature gradient required sometimes means that more information on
heated buildings can be obtained in winter, and unheated ones (such as
churches) may be better having the Thermographic survey at night when the day's
solar gain provides sufficient gradation.
Air leak /
Heat Loss
A significant contribution to heat loss in a building can be caused by poor levels of
air tightness/air leakage . The economic consequences can be increased fuel
bills and system running costs caused by heating systems having to work harder
than necessary to keep the building at a satisfactory temperature. Relatively
minor air leakages in a building can lead to draughts and discomfort for
householders, patches of condensation on walls and inefficient energy
performance. Identifying the source of a draught can be difficult with the air
leakage paths often hidden by kitchen units, bath panels or other boarding.
Air Leakage testing uses a fan system to depressurise the building. The system
is fitted into a frame sealed within an external opening such as a doorframe.
Mechanical ventilation openings are sealed with polythene sheet and tape or
other appropriate materials. Smoke extract fans/vents are closed but not
sealed, and other internal openings (e.g. lift shafts) are left unsealed. As
the building is depressurised, colder air is drawn into the building through
gaps, crack and holes in the building fabric. These may be visually noted,
identified by the use of smoke pencils or recorded on a thermographic survey image.
Combining a blower door test with thermography surveys in this way, enables a
systematic recording, with visual evidence in the form of thermograms and
photographs, of air leakage paths, which can be combined with annotated floor
plans in a Thermographic
survey report if required.
Sound / Noise
Leakage
Noise
leaks can be
difficult to locate. As noise tends to follow the same path as an air leak – a
leak the size of a keyhole will reduce the sound insulation properties of a
wall by 10dB – the same method of blower door and
thermography /Thermographic surveys can be utilized to track down the cause of
noise leaks between rooms or floors.
News Letter for Contractors
Has it gone
amiss? Are the implications understood? Professionals in a number of related
disciplines may not know of its function, but since September 2001 thermography/
Thermographic surveys has sat quietly within Part L2 of the building
regulations.
Look closely and the references will be found under ‘section 2.1b’. At the time
of publication, the technology and techniques required to ascertain the
continuity of insulation/thermal bridging within a building-envelope, were just
emerging. Whilst the objectives of such an inspection were readily agreed, the
methodology and practicality, in terms of cost / benefit, had yet to be
developed.
Most industries are adverse to change and the construction world is no
different. Tighter building regulations require a stronger more advanced design
and build technique, which in turn necessitates higher standards of inspection,
quality audits and product approval.
This is why thermography/ Thermographic survey are becoming an integral part of
the overall process, as it can provide the documentary evidence to prove
compliance.
So
what is thermography?
Thermography is a method by which thermal information of an object can be
acquired, processed and then displayed in a visual way with the data recorded
within the Thermographic surveys remedial works can easily be undertaken. A ‘thermogram’
or ‘thermal image’ can be likened to a picture created with heat, in the same
way that a photograph is a picture created with light. All objects warmer than
–273° C emit infrared radiation. The power and wavelength of the emission
varies with the temperature such that colder objects emit less infrared energy,
this becomes easily recognisable when shown as part of a Thermographic survey.
The small additional cost for building handovers including thermography /
thermographic surveys is minimal, especially if compared to the expenditure on
energy bills during the life cycle of a structure. Controlling the heat loss
leads to an immediate financial benefit for the consumer whilst reducing carbon
emission and the conservation of fuel and power.
A thermographic
building survey not nly shows continuity of insulation but in areas of prolific
heat loss can aid with the development of future design details. The importance
of this tool will inevitably grow as the general understanding and acceptance
spreads; but that’s for the future.
Only professionally qualified thermographic companies or individuals should
conduct thermographic building surveys.
The report delivered should include:
·
Reference
to building drawings/plans
·
Camera
serial number, time and date of survey
·
Environmental
Conditions of Survey
·
Locations
of where the still IR images were collected
·
Qualitative
infrared and digital video showing all buildings external elevations
·
Report
pages detailing any specific observed anomalies with analysis
·
Date,
signature, calibration certificate of Camera and Thermographers certification
number.
For further information on thermography building inspections
please contact Air Pressure Testing, who will be more than willing to assist
with any of your questions or queries.
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