Thermographic Surveys Research Articles

The GRAZ Method—Determination of Urban Surface Temperatures from Aerial Thermography Based on a Three-Dimensional Sampling Algorithm

A novel method to derive surface temperatures from aerial thermography is proposed. Its theoretical foundation, details regarding the implementation, relevant sensitivities, and its application on a day and night survey are presented here. The method differs from existing approaches particularly in two aspects: first, a three-dimensional sampling approach is used to determine the reflected thermal radiation component. Different surface classes based on hyperspectral classification with specific properties regarding the reflection and emission of thermal radiation are considered in this sampling process. Second, the method relies on a detailed, altitude-dependent, directionally and spectrally resolved modelling of the atmospheric radiation transfer and considers the spectral sensitivity of the sensor used. In order to accurately consider atmospheric influences, the atmosphere is modelled as a function of altitude regarding temperature, pressure and greenhouse gas concentrations. The atmospheric profiles are generated specifically for the time of the survey based on measurements, meteorological forecasts and generic models. The method was initially developed for application in urban contexts, as it is able to capture the pronounced three-dimensional character of such environments. However, due to the detailed consideration of elevation and atmospheric conditions, the method is also valuable for the analysis of rural areas. The included case studies covering two thermographic surveys of city area of Graz during daytime and nighttime demonstrate the capabilities and feasibility of the method. In relation to the detected brightness temperatures apparent to the sensor, the determined surface temperatures vary considerably and generally cover an increased temperature range. The two processed surface temperature maps of the city area of Graz are finally used to validate the method based on available temperature recordings.

Multi-hazard assessment of a masonry railway bridge in landslide areas

Earthquakes and landslides pose a high risk to road infrastructure due to unfavorable geological conditions in conjunction with extreme climate events. In particular masonry arch bridges are very often affected by natural events such as floods, landslides, and earthquakes, causing the partial or total collapse of the bridge. To determine the vulnerability to the multiple hazards related to a specific area, a multidisciplinary approach that allows to analyze the different issues is needed. Non-destructive survey strategy based on the study of geo-morphological area, in situ tests and accurate numerical modelling are required to perform a multi-hazard vulnerability assessment of a masonry bridge in a landslide area. In this paper, a multi-disciplinary multi-sensor methodology is proposed based on photogrammetric and thermographic surveys, for the definition of an accurate georeferenced three-dimensional geometrical models of the bridge for a reliable definition of a numerical model to be adopted for the structural assessment of the bridge consistent to a multi-hazard scenario. Namely, a discrete macro-element models (DMEM) based on the software HiStrA Bridge has been applied to determine the soil-structure interaction associated to landslides events. The masonry arch railway bridge chosen for this study is located in a complex geological and geomorphological context. In fact, earth landslides affecting the bridge and poor physical-mechanical characteristics create the conditions for a complex case study. The objective of this study is to assess the vulnerability of masonry bridges subject to the combined effects of landslides, and hydraulic hazard due to bridge occlusion by the modeling of these effects.

Analyzing Thermal Images to Evaluate Thermal Protection in Residential Structures: Lessons from Russian Practices

Building thermography is a non-destructive and effective method for diagnosing the thermal insulation of buildings with various purposes. Regardless of the specifics of conducting thermographic surveys, the obtained thermal images (thermograms) can be analyzed both qualitatively and quantitatively. The first method of analyzing thermal images is implemented using specialized software typically provided with the thermal imaging camera. The second method is carried out based on the results of thermographic surveys following the methodologies regulated by the country’s normative documents. Using the example of thermographic inspection of enclosing structures in a multi-story residential building constructed from reinforced concrete panels, a qualitative assessment of thermal images was conducted to identify potential thermal defects. Thermal bridges were detected in the area of vertical joints of panel plates, and excessive heat losses were identified in the region where the heating device niche is located.Quantitative assessment of thermal images revealed that the thermal resistance in the temperature anomaly area is nearly twice as low as the thermal resistance in the baseline section of the thermogram. One of the variations for evaluating the error of indirect measurements of relative thermal resistance is presented, taking into account the range of measuring instruments used. Verification of the thermal resistance of the enclosing structure of the external wall of the residential building was conducted to ensure compliance with sanitary and hygienic requirements. According to the results of in-situ measurements, it was determined that the temperature on the inner surface of the enclosure was lower than the specified value.

MULTI-SENSOR ANALYSIS FOR EXPERIMENTAL DIAGNOSTIC AND MONITORING TECHNIQUES AT SAN BEVIGNATE TEMPLAR CHURCH IN PERUGIA

Abstract. In the contemporary world, human and natural calamities are challenging our capabilities to preserve heritage and develop innovative safeguard strategies that also address the requirement of sustainability for restoration purposes, still considering the connection between tradition and innovation. This work introduces non-invasive diagnostic practices that offer a new insight of the built environment by studying two different elements of the same architecture of San Bevignate Templar church: a thermographic mapping obtained with special post-processing procedures provided interesting information about the hidden wall pattern, while a prototypal laser scanner, called RGB-ITR, and a UAV survey supplied new insights on the precious paintings. The assessment of the masonry quality constitutes an a priori condition for a reliable estimation of its seismic vulnerability and for the planning of effective yet conservative interventions. The access keys to 'sustainability' therefore consist in the improvement of these contactless investigations, which can be performed both in passive conditions, in the case of thermography surveys, and in active ones, such as for the RGB-ITR scanner, as necessary substitutes for destructive or partial-destructive tests. The research achieved promising results for the characterisation of the architectural structure and the paintings, with the aim of a long-term monitoring of the structure and the decorative apparatus of a monumental heritage located in an area vulnerable to seismic and environmental events.

Developing an IEEE Continuous Thermal Monitoring Standard and a Major Company’s Protection of Their Electrical Assets: Exploring Continuous Thermal Monitoring for Electrical Connections and Components

The process of initiating an IEEE standard is not well understood by many. The objective of this paper is to follow the development of an IEEE Standard Working Group (WG) and the initial efforts to develop an IEEE Standard for continuous thermal monitoring (CTM). This also investigates methods to monitor the operating condition of equipment connections as an alternative to infrared (IR) thermography surveys. It includes a review of methods that can capture data for analysis, trending, and predictive maintenance for personnel safety and extended equipment reliability. Maintenance of electrical switchgear and motor control centers (MCCs) is critical to elevating safety and assuring facilities’ uptime in all industries. Key concerns in every company’s electrical distribution system include the connections and terminations of electrical equipment.

Big in the tropics–Are there thermal advantages of large body size for carpenter bees in hot climates?

AbstractLarge body size is a major advantage for flying insects living in cold climates. Size‐related metabolic heat production allows them to maintain their body temperature high enough for flight even at low ambient temperatures. Due to an elevated risk of overheating, however, large body size should be a disadvantage in hot climates. The present study asked whether large body size may provide a thermal benefit for bees even in tropical environments. To answer this question, we observed the foraging behaviour of two different‐sized carpenter bee species at flowers of Allamanda sp. in the hot semi‐arid region of Brazil. The larger species (Xylocopa frontalis) visited flowers preferentially earlier in the morning and at lower ambient temperatures than the smaller species (X. cearensis). Prior to the foraging peak of X. cearensis, nectar was more abundant in the flowers, which certainly increased the foraging success by X. frontalis. Under cool conditions, moreover, the large species harvested nectar more rapidly than the small species. A thermographic survey revealed that individuals of X. frontalis had higher thoracic temperatures than X. cearensis at the same ambient temperature, and that flower handling became faster with increasing thoracic temperature. These results clearly demonstrate that high thoracic temperatures associated with large body size are an advantage for big bees in hot environments, particularly early in the morning, since they allow an early foraging onset and lead to an increased nectar‐collecting efficiency.

A desiccated dual-species subaerial biofilm reprograms its metabolism and affects water dynamics in limestone

Understanding the impact of sessile communities on underlying materials is of paramount importance in stone conservation. Up until now, the critical role of subaerial biofilms (SABs) whether they are protective or deteriorative remains unclear, especially under desiccation. The interest in desiccated SABs is raised by the prediction of an increase in drought events in the next decades that will affect the Mediterranean regions' rich stone heritage as never before. Thus, the main goal of this research is to study the effects of desiccation on both the biofilms' eco-physiology and its impacts on the lithic substrate. To this end, we used a dual-species model system composed of a phototroph and a chemotroph to simulate biofilm behavior on stone heritage. We found that drought altered the phototroph-chemotroph balance and enriched the biofilm matrix with proteins and DNA. Desiccated SABs underwent a shift in metabolism to fermentation and a decrease in oxidative stress. Additionally, desiccated SABs changed the water-related dynamics (adsorption, evaporation, and wetting properties) in limestone. Water absorption experiments showed that desiccated SABs protected the stone from rapid water uptake, while a thermographic survey indicated a delay in water evaporation. Spilling-drop tests revealed a change in the wettability of the stone-SAB interface, which affected the water transport properties of the stone. Finally, desiccated SABs reduced stone swelling in the presence of water vapor. The biodeteriorative and bioprotective implications of desiccated SABs on the stone were ultimately assessed.

Methodology for the Study of the Vulnerability of Historic Buildings: The Reconstruction of the Transformation Phases of the Church of the Abbey-Castle of Santo Stefano in Monopoli in Puglia (Italy)

The study presented here concerns an analysis of the structural vulnerability of the arm of the church of the Castello di Santo Stefano Abbey in Monopoli in Puglia (Italy). The ancient monument is located on a small “Peninsula” between two ancient natural harbors, 3 km from Monopoli and 5 km from the archaeological site of Egnazia. Studies on the abbey-castle, have revealed different construction and deconstruction phases relating to historical periods of the Roman age, late antique age, medieval age, modern and contemporary age. The castle is typically attributable to a closed courtyard with four arms. The last one, close to the wall on the port of Tramontana, was added at a contemporary time. The arm of the church is characterized by the crypt with opus reticulatum walls from the two surviving bays of the former Benedictine church, from the residential palace of the 18th century, and from the residential extensions of the 20th century. The north-east and north-west arms, born in the 16th century as defensive earth-filled walls with respective bulwarks (north-east pentagonal and north-west at the tip of a spear), were redeveloped between the 17th and 18th centuries into residential buildings with panoramic loggias and overlooking new ditches enclosed by high walled defenses. The study was conducted with non-invasive methods such as: thermographic surveys; archaeological survey; stratigraphic survey of the walls; stratigraphic survey of plants; photogrammetric survey; 3D returns; Morpho-typological survey of the building material making it possible to acquire data on degradation, on the historicization of instability, on the phases of “growth” of the 18th century and of stylistic “reconstructions” of the 19th century. The data acquired, compared with each other, documented: the deterioration and instability of the foundation wall structures (the crypt) and that of the elevated structures: surviving spans of the church and residential building. Alveolization of the building material, deformations, variations in the geometric shape, lack of resistance of the foundation walls due to the typological and qualitative characteristics of the material (opus reticulatum in soft tuff) with high porosity and problems of the church roof system.

Multitemporal Thermal Imagery Acquisition and Data Processing on Historical Masonry: Experimental Application on a Case Study

The recent improvement of infrared image quality has increased the use of thermography as a non-destructive diagnostic technique. Amongst other applications, thermography can be used to monitor historic buildings. The present work was carried out within the framework of the Horizon 2020 European project SHELTER, which aims to create a management plan for cultural heritage subject to environmental and anthropogenic risk. Among the chosen case studies is the Santa Croce Complex in Ravenna (Italy), which is exposed to different hazards, including flooding. The church has a peculiar architecture that develops below the street level, so the internal walls are affected by the deterioration caused by rising humidity. In such a case of advanced degradation, passive thermography cannot be used to its full potential. For this reason, an innovative methodology involving active thermography was first developed and validated with laboratory tests. Secondly, we conducted its first application to a real case study. With this purpose, an active thermography survey with forced ventilation was carried out to enhance different stages of material degradation by means of automatic classification of multitemporal data. These experiments have resulted in a method using an active thermal survey in a high moisture content environment to detect masonry degradation.

Efficacy of calcipotriol plus betamethasone dipropionate foam on psoriatic skin lesions beyond human eyes: An observational study.

Background and AimsCalcipotriol plus betamethasone dipropionate foam has been developed as a new topical therapeutic option for psoriasis, whose effect has been documented mainly on clinical basis.MethodsWe decided to evaluate its efficacy on 11 patients, not only at the clinical level (by using Psoriasis Area Severity Index [PASI], Dermatology Life Quality Index [DLQI], and Psoriasis Global Assessment [PGA] clinimetric indexes) but especially from a subclinical viewpoint (by using videocapillaroscopy and thermography).ResultsAfter 4 weeks of treatment with calcipotriol plus betamethasone dipropionate foam, there was a marked reduction in all three clinimetric indixes PASI, PGA, and DLQI (DLQI mean value decreased from 13.45 ± 3.59 to 6.82 ± 3.31 (p = 0.001), PASI from 7.909 ± 2.857 to 4.582 ± 2.422 (p = 0.001), PGA from 1.8 ± 0.6 to 0.7 ± 0.4 (p = 0.002). From thermographic survey, a significant reduction of mean value of ΔT (temperature difference [°C] between center of the lesions and their periphery [healthy skin]), from 0.28 ± 0.99 to −0.42 ± 0.39 (p = 0.058), was observed. An exceptional reduction of capillaries of psoriatic plaques was detected through videocapillaroscopy (capillary density decreased from 27.91 ± 6.70 capillaries/mm2 to 4.54 ± 2.77 capillaries/mm2 (p = 0.001), with an 83.73% reduction).ConclusionOur results demonstrate both clinical and subclinical efficacy of calcipotriol plus betamethasone dipropionate foam on psoriatic skin lesions. The subclinical improvement detected, not only demonstrates that the therapeutic effect of foam is truly due to a decrease in inflammation, but, being earlier and more effectively detectable than clinical benefit, suggests future applications of thermography and videocapillaroscopy in evaluating the in vivo effect of therapies for psoriasis, and, in general, the course of the disease “beyond human eyes.”

Definition of a Protocol for the Experimental Monitoring of Rising Damp in Three Different Masonry Models with Tuff, Carparo, and Lecce Stone

This work presents a new protocol for monitoring rising damp, which is applied to three masonry models made of tuff, carparo, and Lecce stone. First, the physical characteristics of each stone were derived in the laboratory, which included porosity, imbibition, drying index, permeability, capillarity, and sorptivity. In this case, the protocol provided three columns, one for each material, consisting of five blocks. A layer of cotton tissue was interposed between columned blocks to simulate the hygroscopic behavior of a mortar, allowing a quick disassembly and reassembly of the multiblock columns for a quick weighing. The bottoms of the columns were immersed in water to a level of about three centimeters, providing a constant replenishment for the phenomena of evaporation and rising in the stone. The maximum height achieved by the rising damp depends on the characteristics of the building materials, i.e., the amount and size of pores, pore connectivity, etc. Since these materials have different physical characteristics, the objective was to quantify the rising moisture level of the three materials tested, block by block, in a controlled indoor microclimate environment. The three columns were periodically weighed, the quantity of collected water was evaluated, and a thermographic survey was performed. The results show that at the end of the test, the highest level of rising damp is reached by tuff with a height of 43 cm, followed by Lecce stone and carparo with a height of 40 cm and 21 cm, respectively. The innovation of this study is the proposal of a new flexible and easy-to-apply method for monitoring this phenomenon. It gives clear and numerically comparable results. Moreover, it is applicable to any type of stone, allowing the user to evaluate both the existing state and different design solutions.

A Case Study on Assessment Performance and Energy Efficient Recommendations for Industrial Boiler

As India is a developing country, industrialization is increasing day by day and there is a great need for industry energy audit. Audit helps to maintain and save energy from being wasted and helps in achieving highest efficiency of industrial equipment. This paper contains an actual industry audit report on boiler performance. This paper contains a report on Thermal analysis of boilers, thermal skin heat loss of boilers, O2 percentage control in flue gases to standard values, effect of coal additive, etc. This paper also contains a report on waste heat recovery options for thermal boiler, flue efficiency monitor, infrared thermometer, ultrasonic peak detector IR thermal imager. These equipment are used for energy assessment of boilers. Thermography survey of boiler surface is carried out to estimate the radiation and the other losses and the result of this total annual saving after insulation repairing or maintenance is Rs.8.48 lakh and investment is around Rs.6.31 lakh. Economizer performance of both the ISGEC and Thermax boiler can be improved with the help of suggested measures. It will help to save approximately rupees Rs.38.42 Lakh annually and investment on maintenance cost is negligible. In short, this paper deals with assessment of all boilers, evaluates their efficiencies and losses to identify energy saving opportunities and presents them in a report with their payback periods. Keywords: Energy, Energy audit, assessment, boiler.

3D Thermal Monitoring of Jointed Rock Masses through Infrared Thermography and Photogrammetry

The study of strain effects in thermally-forced rock masses has gathered growing interest from engineering geology researchers in the last decade. In this framework, digital photogrammetry and infrared thermography have become two of the most exploited remote surveying techniques in engineering geology applications because they can provide useful information concerning geomechanical and thermal conditions of these complex natural systems where the mechanical role of joints cannot be neglected. In this paper, a methodology is proposed for generating point clouds of rock masses prone to failure, combining the high geometric accuracy of RGB optical images and the thermal information derived by infrared thermography surveys. Multiple 3D thermal point clouds and a high-resolution RGB point cloud were separately generated and co-registered by acquiring thermograms at different times of the day and in different seasons using commercial software for Structure from Motion and point cloud analysis. Temperature attributes of thermal point clouds were merged with the reference high-resolution optical point cloud to obtain a composite 3D model storing accurate geometric information and multitemporal surface temperature distributions. The quality of merged point clouds was evaluated by comparing temperature distributions derived by 2D thermograms and 3D thermal models, with a view to estimating their accuracy in describing surface thermal fields. Moreover, a preliminary attempt was made to test the feasibility of this approach in investigating the thermal behavior of complex natural systems such as jointed rock masses by analyzing the spatial distribution and temporal evolution of surface temperature ranges under different climatic conditions. The obtained results show that despite the low resolution of the IR sensor, the geometric accuracy and the correspondence between 2D and 3D temperature measurements are high enough to consider 3D thermal point clouds suitable to describe surface temperature distributions and adequate for monitoring purposes of jointed rock mass.

Automatic Detection of Linear Thermal Bridges from Infrared Thermal Images Using Neural Network

Detecting thermal bridges in building envelopes should be a priority to improve the thermal performance of buildings. Recently, thermographic surveys are being used to detect thermal bridges. However, conventional methods of detecting thermal bridges from thermal images rely on the subjective judgment of audits. Research has been conducted to automatically detect thermal bridges from thermal images to improve problems caused by such subjective judgment, but most of these studies are still in the early stage. Therefore, this study proposes a linear thermal bridge detection method based on image processing and machine learning. The proposed method includes thermal anomaly area clustering, feature extraction, and an artificial-neural-network-based thermal bridge detection. The proposed method was validated by detecting the thermal bridges in actual buildings. As a result, the average precision, recall, and F-score were 89.29%, 87.29, and 87.63%, respectively.

Developing Guidelines for the Use of Passive Thermography on Cultural Heritage in Tropical Climates

Infrared thermography (IRT) has been a very successful tool for the diagnosis and monitoring of cultural heritage restoration projects. It has been used to identify anomalies, moisture issues, etc., in historic buildings. Although it is a promising tool, one of the limitations is that a method to deploy it onsite has not been standardized. This is due to the different variables that might affect thermal signatures captured by the thermal camera, when onsite. Especially since environmental conditions play a major role in thermography, the process must vary from region to region significantly. That said, efforts have been made over the years to establish some base standards for designated purposes of infrared thermography in the construction field. These standards and best practice methods, although comprehensive, do not effectively help with issues that are contextual to the location of the building, for instance, tropical climates, such as India. This paper aims to suggest guidelines for a passive approach of thermography, based on practical applications and procedures followed during the thermographic survey at the former British Residency in Hyderabad, India. Additionally, this paper explores the avenues through which region specific guidelines can be established.

Three-Dimensional Thermal Mapping from IRT Images for Rapid Architectural Heritage NDT

Thermal infrared imaging is fundamental to architectural heritage non-destructive diagnostics. However, thermal sensors’ low spatial resolution allows capturing only very localized phenomena. At the same time, thermal images are commonly collected with independence of geometry, meaning that no measurements can be performed on them. Occasionally, these issues have been solved with various approaches integrating multi-sensor instrumentation, resulting in high costs and computational times. The presented work aims at tackling these problems by proposing a workflow for cost-effective three-dimensional thermographic modeling using a thermal camera and a consumer-grade RGB camera. The discussed approach exploits the RGB spectrum images captured with the optical sensor of the thermal camera and image-based multi-view stereo techniques to reconstruct architectural features’ geometry. The thermal and optical sensors are calibrated employing custom-made low-cost targets. Subsequently, the necessary geometric transformations between undistorted thermal infrared and optical images are calculated to replace them in the photogrammetric scene and map the models with thermal texture. The method’s metric accuracy is evaluated by conducting comparisons with different sensors and the efficiency by assessing how the results can assist the better interpretation of the present thermal phenomena. The conducted application demonstrates the metric and radiometric performance of the proposed approach and the straightforward implementability for thermographic surveys, as well as its usefulness for cost-effective historical building assessments.

An innovative approach towards enhancing energy conservation in buildings via public engagement using DIY infrared thermography surveys

Abstract Energy consumption in urban environment in the EU accounts for about 40% of the total energy consumption, and the majority of this energy is utilised for heating and air conditioning of buildings. Hence the process of insulating and retrofitting of relatively old buildings is essential to enhance the thermal performance and hence contribute to energy and carbon emission reduction. There is a need to enhance people's engagement and education in relation to such issues to inspire and encourage positive actions and investment from the public. This paper presents an approach of combining a novel training process using a low-cost infrared thermal camera with small scale building model to promote DIY (Do-It-Yourself) infrared survey for the public to evaluate the performance of their own homes in order to identify any issues related to insulation or air leaks from the building envelop to encourage them to take corrective actions. The work included the engagement of 50 people to survey their own homes to capture the technical findings as well as their personal reaction and feedback. The results show that 88% of participants have found the educational session helpful to understand the infrared thermography; and 92% have considered the infrared camera to be an effective tool to indicate location of heat losses. Additionally, 90% of participants trust that the thermal camera has helped them to identify insulation defects that cause heat losses in their homes. Moreover, 84% believe that the thermal imaging has convinced them to think more seriously about the heat losses of their homes and what they could do to improve that. The experimental thermography surveys have shown that many houses have limitations in terms of thermal insulation which have been identified by the participants. This DIY interaction has provided enhanced public engagement and energy awareness via the use of the technology. The financial issues are also found to be critical, as none of the participants would have done the survey if they had to pay for it. Hence, this paper provides a solution for households with limited budgets.

Analyzing capacity of a consumer-grade infrared camera in South Africa for cost-effective aerial inspection of building envelopes

Prohibitive equipment cost and certain export regulations are the major obstacles to the widespread adoption of infrared (IR) thermography when evaluating building envelopes. In this work, we propose the use of an affordable and easily available camera as a first step of making the technology accessible. Combined with image post-processing, we hypothesize that a low-cost, low-resolution, and consumer-grade device can provide an economic alternative for the periodic evaluation of building envelopes. Following a market survey, the Seek Thermal Compact (STC) was chosen for evaluation. The STC was able to accurately measure the temperature of surfaces and distinguish small thermal anomalies (3 mm in diameter), and the IR images can be post-processed to reasonably estimate the anomaly areas. The STC was particularly effective when images were taken within 1.75 m from the surface. The 1.75 m distance did not pose a challenge in this study, as the goal was to mount the selected IR camera on an unmanned aerial vehicle for the surveys. The small size and weight of the STC were also useful. The results from the analysis of the capability of the STC and the image post-processing techniques may help form the basis of future investigations aiming at lowering the cost of building thermographic surveys.

Energy Refurbishment of the General Physiology Institute at Sapienza University Campus

The energy requalification of the existing building heritage is one of the pillars European Union energy policy. A large part of the building heritage was built without taking into consideration the problem of energy consumption. With the aim of energy efficiency and energy savings in electrical uses, there are wide and diversified possibilities for improvement, including interventions on the building envelope and on the systems, with the introduction, where possible, of renewable energy sources. In this context, the redevelopment of historic buildings constitutes an important challenge, which involves both historical-artistic aspects and technological aspects relating to the improvement of energy efficiency and comfort. A critical analysis of every possibility is essential to preserve the balance between efficiency and architecture. The purpose of the study is the energy retrofitting of the Institute of General Physiology located within the “Sapienza” University campus. The proposed interventions include the renovation of the whole building envelope, investigated by thermographic surveys, and the installation of new heating and cooling systems. The results were analysed to identify the best intervention for a sustainable energy renovation of the historic building, taking into account the preservation of its architectural values and making it suitable for modern use.

Termografía infrarroja para el diagnóstico térmico confiable con alta replicabilidad y bajo costo de viviendas en Mendoza, Argentina

The aim of the paper is to assess the usefulness of infrared thermography for a quick diagnostic of the thermal performance of the existing building stock. A representative housing case study in the city of Mendoza (32o40’SL, 68o51’WL, 750m above sea level) was selected and infrared imaging was carried out with a low cost thermograph camera (FLIR i3) at two times every day, in the late evening (8 pm) and in the early morning (7 am), for avoiding possible mistakes due to incident direct solar radiation. Emissivity was introduced in the camera according with local material studies. At the same time continuous measurement of air temperature inside and outside were taken with data-loggers with the objective of examining in detail the obtained results by the thermographic survey. Because the case studied has a high thermal inertia the survey in the evening shows better the different behaviour of construction materials. It is concluded that the thermogaphic survey resulted a valuable tool for quick thermal diagnostic in building certification if a specific protocol is followed in order to obtain accurate results.