INFRARED TECHNOLOGY FOR PRESERVATION
by Phillip C. McMullan, Thermo-Scan Inspections, Carmel, Indiana
ABSTRACT
Defining the scope and specifications of historic building preservation projects can be very challengingand requires both nondestructive testing in the field and in the laboratory. In field testing, the use of infrared (IR) thermal imaging on building envelope components can provide particularly valuable information, which responds to renewed interest in energy efficiency and a new focus on moisture detection for mold prevention. In addition, infrared imaging can identify otherwise hidden changes in the structural condition of a historic building.
This paper details two different historic preservation projects: a school building built in 1919 and a mansion built in 1911, in which the use of infrared has been invaluable. The test results provided documented information on energy efficiency, moisture detection, and structural condition, which was then incorporated into the preservation project specifications.
Keywords: Infrared, thermal imaging, IR building surveys, historic preservation, historic buildings.
INTRODUCTION
All components of a building emit infrared radiation — heat that is not visible to the human eye. The infrared camera senses that infrared radiation and electronically displays a visual image of the thermal patterns. Technicians trained and certified in building diagnostics can determine from this image what components have surface heat patterns that represent conductive or convective heatloss/gain.
When buildings are imaged with infrared cameras during cold weather, with a minimum inside-outside delta T of 18 Fahrenheit degrees, the differing thermal patterns will appear depending on the age and type of construction. (Note: A building may be imaged during the summer months as longas the minimum delta T is present and the image scales will be inverted.)
This paper focuses on two wall systems. The first is a masonry barrier wall system at Withrow HighSchool, which is more than fifty years old. The weather resistance of the walls, which consist ofseveral vertical planes or wythes of masonry, is based on the ability of the brick to absorb and block rainwater. The second is located at Oldfields Estate, which embodies three eras of construction, the original house built in 1911, and additions built in 1932 and 1939. In areas of the walls, which contain elevated levels of moisture, the infrared camera detects conductive heat loss patterns to the brick exterior surface. This heat loss is associated with the lowering of the thermal resistance of the wall assembly caused by the moisture within the wall assembly. As the building was thermally imaged, locations of thermal anomalies were documented. Those anomalies that were conductive and not convective heat loss were documented for further investigation and "neutron thermalization" testing.
Pursuant to American Society of Nondestructive Testing (ASNT) “Handbook of Nondestructive Testing” Volume 3, the guidelines for a building envelope infrared inspection were followed in this inspection.
INSPECTION FINDINGS AT WITHROW HIGH SCHOOL
Findings that are common to all six building sections, A, B, C, D, E and K are as follows:
by Phillip C. McMullan, Thermo-Scan Inspections, Carmel, Indiana
ABSTRACT
Defining the scope and specifications of historic building preservation projects can be very challengingand requires both nondestructive testing in the field and in the laboratory. In field testing, the use of infrared (IR) thermal imaging on building envelope components can provide particularly valuable information, which responds to renewed interest in energy efficiency and a new focus on moisture detection for mold prevention. In addition, infrared imaging can identify otherwise hidden changes in the structural condition of a historic building.
This paper details two different historic preservation projects: a school building built in 1919 and a mansion built in 1911, in which the use of infrared has been invaluable. The test results provided documented information on energy efficiency, moisture detection, and structural condition, which was then incorporated into the preservation project specifications.
Keywords: Infrared, thermal imaging, IR building surveys, historic preservation, historic buildings.
INTRODUCTION
All components of a building emit infrared radiation — heat that is not visible to the human eye. The infrared camera senses that infrared radiation and electronically displays a visual image of the thermal patterns. Technicians trained and certified in building diagnostics can determine from this image what components have surface heat patterns that represent conductive or convective heatloss/gain.
When buildings are imaged with infrared cameras during cold weather, with a minimum inside-outside delta T of 18 Fahrenheit degrees, the differing thermal patterns will appear depending on the age and type of construction. (Note: A building may be imaged during the summer months as longas the minimum delta T is present and the image scales will be inverted.)
This paper focuses on two wall systems. The first is a masonry barrier wall system at Withrow HighSchool, which is more than fifty years old. The weather resistance of the walls, which consist ofseveral vertical planes or wythes of masonry, is based on the ability of the brick to absorb and block rainwater. The second is located at Oldfields Estate, which embodies three eras of construction, the original house built in 1911, and additions built in 1932 and 1939. In areas of the walls, which contain elevated levels of moisture, the infrared camera detects conductive heat loss patterns to the brick exterior surface. This heat loss is associated with the lowering of the thermal resistance of the wall assembly caused by the moisture within the wall assembly. As the building was thermally imaged, locations of thermal anomalies were documented. Those anomalies that were conductive and not convective heat loss were documented for further investigation and "neutron thermalization" testing.
Pursuant to American Society of Nondestructive Testing (ASNT) “Handbook of Nondestructive Testing” Volume 3, the guidelines for a building envelope infrared inspection were followed in this inspection.
INSPECTION FINDINGS AT WITHROW HIGH SCHOOL
Findings that are common to all six building sections, A, B, C, D, E and K are as follows:
1-800-481-5748
Infrared Technology For Preservation
