Thermographic analysis: a powerful diagnostic tool for enhanced analysis

Thermal inspections include all methods in which devices are used to detect heat in order to measure temperature variations in components, structures, systems, or physical processes. One of these methods is infrared thermography: a remote sensing technique based on acquiring images in the infrared field.

Infrared thermography allows measuring the energy in the infrared emitted by bodies at a temperature different from absolute zero using appropriate sensors and correlating it to the body’s surface temperature.

It is used to make diagnoses that identify weak points leading to a decrease in the building’s energy performance, without resorting to invasive investigations, planning strategies to improve performance effectively.

Thermographic Analysis: What is it used for?

Thermographic analysis is a non-destructive diagnostic technique that uses a special camera to measure the infrared radiation (IR) emitted by the element under examination, converting it into thermal information to determine the surface temperature.

The generated electrical signals are then projected onto a monitor and transformed into images, called thermograms. Every object emits energy in the form of electromagnetic radiation, the intensity of which varies according to the temperature. The surface temperature is also influenced by the thermal conductivity and specific heat of the material being analyzed.

By visualizing the differences in surface temperature (thermal anomalies), thermography allows detecting anomalies indicating incipient failures or malfunctions in a system, process, or component that require corrective actions.

It is a particularly useful test in various fields: from the steel industry and thermal processes to civil plant engineering, from the electronic industry to industrial plant engineering, to applications in the field of medical prevention and diagnosis.

Thermography is also useful for diagnosing issues such as:

Finally, thermography is part of energy efficiency, which has become a necessary requirement today for both new buildings and renovating existing ones. In the construction field, for example, with thermography, it becomes easy to identify thermal bridges and any heat losses from the opaque and non-opaque building envelopes. In this regard, the use of thermal bridge calculation software could be useful for careful planning to minimize the impact of thermal bridges already in the design phase.

How infrared thermography works

The analysis is carried out using an infrared thermal camera, a kind of camera equipped with special sensors that detect the surface temperature of bodies and display it in a readable way through a color map.

The thermal camera is therefore the core of the whole apparatus as it is the tool through which the temperature of the body or area of interest is detected.

Unlike visible light cameras, thermal cameras create temperature images, measure the infrared energy (IR) emitted by a body, and convert it into an image where each point represents a temperature value.

The thermal cameras available on the market today are divided into 2 types:

• cooled;
• uncooled.

The highest precision is achieved with cooled thermal cameras, which, however, have issues that do not exist in the other group and often higher costs. These are the reasons why, especially in the construction field (where lower precision is required for many parameters), uncooled thermal cameras are more widespread.

Cooled Thermal Cameras

Cooled thermal cameras guarantee the highest measurement precision. They consist of:

• a sensor;
• a cooling system;
• a scanning system;
• an objective lens.

Cooled thermal cameras mount miniaturized sensors, called photodetectors, devices made of semiconductor materials in which the release of electric charges is directly proportional to the absorption of photons. The reason for cooling in these types of instruments is precisely related to the efficiency of the sensors, as the precision increases as the detector’s temperature decreases.

Uncooled thermal cameras

Uncooled thermal cameras are currently the most widely used, especially in the construction, plant engineering, and predictive maintenance fields. They use a sensor called a microbolometer, similar to the sensors found in digital cameras. Each pixel of the microbolometer directly corresponds to a point in the thermal image, without mechanical scanning systems. This makes the device lightweight, robust, and easy to use.

Unlike cooled thermal cameras, they do not require a cooling system because the microbolometer operates correctly even at room temperature. This results in a more compact structure, lower energy consumption, and much simpler maintenance.

The geometric resolution depends on the number of pixels in the sensitive matrix: the denser the matrix, the more detailed the thermal image will be.

This technology is the most widespread because it offers an excellent balance between performance, cost, and maintenance. Uncooled thermal cameras are ideal for:

• construction;
• plant engineering;
• predictive maintenance;
• energy diagnosis;
• general industrial applications.

Thermographic inspection tools: how to choose the right one

To carry out a reliable thermographic analysis, it is essential to use tools suitable for the investigation scenario. The thermal camera is the main device, but it can be complemented by additional tools, such as thermo-hygrometers, humidity meters, or anemometers, useful for correctly interpreting the thermal anomalies detected.

The choice of equipment depends on the type of intervention: energy diagnosis, leak detection, plant maintenance, industrial checks, or inspections on materials and thermal processes. The more complex the application, the greater the precision of the instrument and the quality of the IR sensor must be.

How to choose an infrared thermography camera

Choosing an infrared thermography camera is a complex process that requires careful evaluation based on specific needs and the scope of application. It is necessary to consider some parameters in order to understand which type of instrument is most suitable for your needs:

• temperature range: indicates the thermal scale within which the operator will presumably work. Common infrared thermography cameras generally cover from -20°C to +120°C, suitable for most building applications. However, for industrial applications, there are cameras with ranges up to 2000°C;
• thermal resolution: indicates the maximum difference in terms of degrees that the sensor is able to perceive in a single image: the higher the thermal resolution, the better the sensor and consequently the thermal response that the sensor itself will be able to provide;
• thermal accuracy: defined as the accuracy of the measurement in the absolute temperature scale of an object;
• geometric resolution of the sensor: which in the case of uncooled cameras, the majority of cameras on the market, coincides with the number of pixels that make up the microbolometer matrix;
• spectral range: represents the infrared window analyzed by the infrared thermography camera, it is another element to consider. There are two main ranges: the near infrared (short wave) from 2 to 5 µm and the far infrared (long wave) from 8 to 12-14 µm;
• sensor acquisition frequency: which typically varies from 9 to 50 Hz, can be significant, especially in industrial and mechanical fields where moving objects are analyzed. Some infrared thermography cameras can record sequences of thermal images, creating real thermal videos;
• price: high-end infrared thermography cameras have high costs, but infrared technology evolves slowly, with sensors that remain at the top of performance for many years.

Active and passive thermographic analysis

Infrared thermography is divided into two main categories based on the presence or absence of a specific thermal excitation system. We speak respectively of active and passive thermographic techniques.

Passive Thermography

In passive thermography, the camera frames the surface of the body, the object of investigation, and acquires thermal images. The body undergoes no alteration because passive thermography simply detects the thermal radiation emitted from the surface of the object due to its intrinsic state or intrinsically linked to its operating conditions. Passive thermography is typically used in steady-state or quasi-steady-state conditions, to inspect electrical and mechanical systems, in process diagnostics (ovens, chemical reactors), and installation.

Active Thermography

In active thermography, a non-stationary heat flow is generated for the sole purpose of thermographic tests on the test object. The sources of the heat flow can be natural or artificial and are chosen based on the specific applications and their specific requirements. The flow can be impulsive, stepwise, or periodic. Active thermography is used for material inspections, in the technology of metallic or composite materials and in that of welds and joints, to detect and display hidden elements not visible in steady thermal conditions, but highlightable by inducing a forced thermal transient in the material.

Comparison between thermographic scans and traditional inspections

Thermographic scans differ substantially from traditional inspections (visual or destructive), especially due to their non-invasive nature, speed, and sensitivity of the investigations. While a visual inspection is limited to detecting macroscopic defects such as cracks, detachments, or surface imperfections, thermography allows for highlighting thermal anomalies that are not visible to the naked eye, such as thermal bridges, heat losses, air leaks, or moisture.

To better understand the specific advantages of thermographic scanning compared to traditional methods, it is useful to consider some key aspects:

• non-invasiveness and speed: thermographic analysis does not require demolition or coring, and can be performed during the normal operation of the building;
• thermal sensitivity: thanks to the ability to detect very small temperature differences, thermography identifies defects even in the early stages, when they are not yet structurally evident;
• extensive spatial coverage: a thermal camera can “map” large surfaces in a short time, providing a complete thermal representation of the building envelope, which would require numerous point surveys with traditional methods;
• quantification and documentation: thermographies generate documentable data (thermal maps, thermograms) that can be archived over time, allowing for before/after comparisons and verification of energy improvements.

Unlike thermography, traditional inspections often prove to be limited. Visual checks almost never detect thermal bridges or air leaks, while destructive tests require more time and higher costs, and are only applicable in confined areas. They therefore offer a less complete diagnostic picture compared to the overall view provided by thermographic scans.

Advantages of thermography compared to traditional methods

Why is infrared thermography important in architecture and engineering?

Infrared thermography is a fundamental tool for architects and engineers because it allows for non-invasive assessment of the thermal and structural behavior of the building, quickly identifying anomalies that affect energy efficiency, quality of the envelope, and durability of structures.

From an energy perspective, thermography allows to:

• improve energy efficiency by highlighting heat losses and thermal bridges;
• verify construction quality by identifying insulation installation defects;
• plan targeted interventions to avoid unnecessary work;
• document and certify performance, supporting diagnosis and post-intervention checks.

Thanks to the ability to transform invisible phenomena into objective data, thermography integrates perfectly with BIM approaches and sustainable design strategies, enabling simulations and optimizations based on real information.

A significant contribution is also made in the field of historic buildings, where interventions must be non-invasive. Thermographic investigations allow to:

• identify arches, vaults, and original structures hidden beneath finishes;
• detect detachments, degradations, and moisture that are not visible;
• understand the differences in thermal behavior between materials, useful for restorations and consolidations.

In historical contexts, infrared thermography thus provides reliable support compatible with the characteristics of the artifact, enhances knowledge of the building, and allows for more informed and effective interventions.

Why infrared thermography is important in architecture and engineering

How does infrared thermography improve energy diagnosis in buildings?

Infrared thermography allows for the precise identification of heat losses, thermal bridges, and air infiltrations, elements that are often invisible to a visual inspection. Thanks to reliable thermal maps, it is possible to:

• assess the condition of insulation and detect any discontinuities;
• identify moisture or infiltrations that can compromise efficiency and durability;
• compare conditions before and after energy improvement interventions.

In this way, thermography provides concrete data for a more complete and accurate energy diagnosis, supporting targeted interventions and reducing waste and inefficiencies.

Using thermographic investigations for the design and optimization of building envelope performance

Thermographic investigations represent a strategic tool even in the design phase, as they allow for the verification of the actual behavior of the envelope and the optimization of the building’s energy performance. Thermal analysis allows for:

• validating design choices related to insulation, materials, and construction details;
• integrating BIM simulations with real data for more reliable forecasts;
• planning targeted interventions, limiting unnecessary work;
• verifying the correct execution of work and post-intervention improvements.

Thermography thus ensures a more informed, effective design based on objective data, improving the building’s performance and reducing risks and inefficiencies, even in the presence of critical elements such as ventilated roofs, essential for proper air exchange and moisture prevention.

What are the advantages and limitations of thermography?

Thermography offers numerous advantages, making it an increasingly used tool in various sectors, from construction to industrial engineering. At the same time, it presents some limitations related to equipment, environmental conditions, and the need for qualified operators. Below are the main advantages and limitations summarized.

Advantages of thermography

Thermography allows for the analysis of the temperature of any object without direct contact, enabling repeated measurements over time and monitoring of high-temperature bodies or hazardous conditions. Among the main advantages are:

• high sensitivity: detects temperature differences in the order of hundredths of a degree;
• wide measurement range: standard instruments cover temperatures from 20°C to 1500°C;
• in-service inspections: does not require the shutdown of systems, allowing checks on motors, bearings, or high-voltage cabinets;
• early detection of faults: increases the chances of detecting defects even before they become critical;
• targeted and preventive interventions: reduces maintenance costs and the risks of catastrophic events such as fires or sudden production stoppages.

Limitations of thermography

The use of thermography presents some technical and operational limitations that must be carefully evaluated to obtain reliable results:

• high cost: professional equipment can be expensive;
• need for qualified operators: the correct interpretation of data requires experience and training;
• low emissivity materials: can make it difficult to obtain precise data;
• environmental influence: climatic conditions or external emissions can interfere with measurements, especially in construction;
• protection of the instrument: in some cases, it is necessary to shield the thermal camera from environmental emissions for accurate measurements.

Thermographic testing protocols for quality control in construction

The use of thermography in construction requires standardized procedures to ensure reliable and comparable results. Testing protocols define criteria, operational methods, and limits of application, ensuring that thermal measurements are correct, repeatable, and objectively interpretable.

What are the application areas of thermography?

Thermography finds wide application in construction due to its versatility and ability to provide accurate information without invasive interventions. The main areas include:

• energy diagnosis of buildings, to identify losses, thermal bridges, and inefficiencies of the envelope;
• verification of the conservation status of properties, to identify areas of degradation, moisture, or surface detachments;
• search for system faults, both electrical and mechanical, before they become critical.

More specifically, thermography is used for:

• electrical systems, both high and low voltage;
• photovoltaic panels, to detect defective modules or hot spots;
• water infiltrations, to identify leaks or hidden moisture;
• evaluation of structural integrity, through the detection of thermal anomalies in structures and materials;
• maintenance of MEP (mechanical, electrical, and plumbing) systems, with periodic checks and targeted interventions.

Thermographic analysis on electrical systems

Thermographic analysis of electrical systems is a fundamental procedure to ensure the safety and proper maintenance of electrical infrastructures. Through the detection of infrared radiation, thermography allows for the identification of abnormal overheating, contact defects, load imbalances, and other early signs of malfunction that, if ignored, can lead to failures, blackouts, or fires.

In the electrical sector, the most common applications concern two main categories:

• high voltage installations: in high voltage systems, thermography is essential for identifying overheating phenomena of connections, oxidations, inadequate fixings, and defects of insulators. At these voltage levels, even small increases in resistance can generate high temperatures, with the risk of service interruptions or fires. The ability to perform inspections on live systems makes thermography an indispensable tool for verifying the actual state of components in operation and preventing sudden failures;
• low voltage installations: in low voltage systems, such as electrical panels, distribution systems, and control units, thermography allows for the rapid identification of high-temperature points, high-resistance connections, corrosion phenomena, load imbalances, or internal defects of circuit breakers. Here too, undetected overheating can degrade materials, interrupt service continuity, or trigger fires. Thermographic analysis allows for the scheduling of targeted maintenance interventions and verifying the effectiveness of restoration operations.

Thermographic analysis on photovoltaic panels

Thermography can be used to evaluate the performance of a photovoltaic system throughout its life cycle. It allows for the detection of:

• defective or damaged photovoltaic cells;
• broken or disconnected connections;
• shading or dirt accumulation on photovoltaic panels.

Thanks to thermal analysis, it is also possible to diagnose complex phenomena such as photovoltaic PID (Potential Induced Degradation), which reduces the efficiency of modules due to electrical degradation.

Thermography also proves to be a valuable tool for monitoring the status of solar inverters: by visualizing the temperature distribution, it is possible to identify abnormal thermal variations that indicate malfunctions or internal faults, allowing for timely and targeted interventions.

This approach allows for optimizing preventive maintenance, improving the energy efficiency of the system, and reducing the risks of downtime or irreversible damage to modules and inverters.

Thermographic analysis for the detection of water infiltrations

Thermography represents an extremely effective tool for identifying water infiltrations, hidden moisture, and points where the building envelope loses its tightness. The principle behind it is thermal inertia: wet materials and dry materials react differently to temperature changes.

Thanks to this difference, the thermal camera allows for recognizing:

• areas with moisture accumulation not visible to the naked eye;
• points where water infiltrates through roofs, walls, balconies, or windows;
• detachment and deterioration of plaster caused by prolonged water presence;
• infiltration paths within the stratifications, often impossible to identify with traditional methods.

Thermographic analysis for the evaluation of structural integrity

Thermography represents an effective tool for assessing the health status of structures and identifying defects invisible to the naked eye. By detecting differences in surface temperature, it is possible to highlight anomalies related to mechanical stress, material degradation, or surface detachments.

With this method, it is possible to recognize:

• cracks and fissures not visible from the outside;
• detachment of plaster or coverings;
• areas with internal degradation of structural materials;
• possible infiltration paths or critical points that may compromise safety.

Thermographic investigation thus allows for precisely locating structural problems, planning targeted interventions, and reducing time and costs of preventive or extraordinary maintenance.

Thermographic diagnosis in the maintenance of MEP systems

Thermography is an essential tool for monitoring MEP systems (Mechanical, Electrical, Plumbing). It allows for identifying overheating, leaks, and inefficiencies in mechanical, electrical, and plumbing components.

Among the easily detectable issues with thermography are:

• overheating in pumps, motors, and valves;
• water or fluid leaks in pipes and plumbing systems;
• defective or overloaded electrical connections in distribution panels;
• localized malfunctions that could compromise the efficiency of the system.

This approach allows for scheduling targeted interventions, reducing the risks of sudden failures, optimizing maintenance costs, and improving the overall efficiency of the systems.

Applications of thermography in BIM flows and digital twin models

Thermography finds an increasingly widespread application in BIM flows and digital twin models, key tools for the design, management, and maintenance of buildings. By integrating thermographic data into digital models, it is possible to obtain a reliable representation of energy performance and the actual conditions of structures and systems.

This integration allows for:

• detecting and documenting thermal anomalies directly in the BIM model;
• planning maintenance interventions based on real data, improving operational efficiency;
• verifying the performance of building envelopes and systems throughout the building’s life cycle;
• creating digital twins updated in real-time, useful for energy simulations and preventive diagnoses.

The use of specific software makes thermographic analysis even more effective, allowing for processing collected data, generating detailed thermograms, and producing professional reports. Among the main features are:

• processing and comparing thermal images;
• mapping hot spots and detected defects;
• integration with BIM and digital twin models;
• data storage and management for future interventions or quality checks.

These tools improve the accuracy of diagnoses, facilitate communication of results, and support rapid and targeted decisions, both in the design phase and in maintenance.

With this system, you can process detailed thermograms, identify critical points and anomalies, generate professional reports, and integrate data with BIM or digital twin models. Your infrared thermography investigations thus become an operational tool to optimize the performance of the building envelope, support targeted interventions, and make design and maintenance decisions based on objective data. Try this solution now and discover how to transform thermographic data into effective and targeted interventions.

FAQ – Thermographic analysis

What is thermographic analysis?

Thermographic analysis is a non-destructive diagnostic technique that uses a thermal camera to convert the infrared radiation emitted by surfaces into thermal images useful for identifying anomalies, losses, and defects not visible to the naked eye.

In which fields is thermography used?

Thermography is applied in construction, plant engineering, industry, process monitoring, electrical and mechanical controls, material diagnostics, cultural heritage, photovoltaics, and energy checks.

How does a thermal camera work?

The thermal camera detects the infrared radiation emitted by materials and transforms it into a thermogram. IR sensors record temperature differences, making it immediately identifiable losses, faults, and thermal anomalies.

What is the difference between active and passive thermography?

Passive thermography records the natural heat emitted by surfaces without altering them. Active thermography, on the other hand, uses an external thermal source to highlight defects or hidden elements that do not emerge under stationary conditions.

What can thermography identify in construction?

It allows for detecting thermal losses, thermal bridges, water or air infiltrations, moisture, insulation defects, problems in radiant systems, and structural degradation.

Why is thermography useful in energy diagnosis?

It offers precise thermal maps that help verify the condition of insulation, assess critical points of the envelope, compare conditions before and after an intervention, and plan targeted works to reduce inefficiencies.

What tools are needed for reliable thermographic analysis?

In addition to the thermal camera, thermo-hygrometers, moisture meters, and climatic instruments can be used to ensure a correct interpretation of the collected data.

How to choose the most suitable thermal camera?

The choice depends on the application. It is necessary to evaluate temperature range, thermal and geometric resolution, accuracy, spectral range, acquisition frequency, and robustness of the technology concerning the area of use.

What is the role of thermography in BIM flows and digital twin?

Thermographic data integrated into digital models allow for documenting defects, verifying actual performance, planning maintenance based on updated data, and improving the energy management of the building throughout its life cycle.