Mechanical Properties and Cooperation Mechanism of Corroded Steel Plates Retrofitted by Laser Cladding Additive Manufacturing under Tension.

As a metal additive manufacturing process, laser cladding (LC) is employed as a novel and beneficial repair technology for damaged steel structures. This study employed LC technology with 316 L stainless steel powder to repair locally corroded steel plates. The influences of interface slope and scanning pattern on the mechanical properties of repaired specimens were investigated through tensile tests and finite element analysis. By comparing the tensile properties of the repaired specimens with those of the intact and corroded specimens, the effectiveness of LC repair technology was assessed. An analysis of strain variations in the LC sheet and substrate during the load was carried out to obtain the cooperation mechanism between the LC sheet and substrate. The experimental results showed that the decrease in interface slope slightly improved the mechanical properties of repaired specimens. The repaired specimens have similar yield strength and ultimate strength to the intact specimens and better ductility as compared to the corroded specimen. The stress-strain curve of repaired specimens can be divided into four stages: elastic stage, substrate yield-LC sheet elastic stage, substrate hardening-LC sheet elastic stage, and plastic stage. These findings suggest that the LC technology with 316 L stainless steel powder is effective in repairing damaged steel plates in civil engineering structures and that an interface slope of 1:2.5 with the transverse scanning pattern is suitable for the repair process.

Sustainable energy solutions: Well retrofit analysis and emission reduction for a net-zero future in the Intermountain West, United States of America.

To achieve net-zero emissions by 2050, we need economic means of sequestering carbon dioxide (CO2) and reducing greenhouse gas emissions (GHG). We analyze the sequestration potential of the Intermountain West (I-West) region, US, as a primary energy transition hub through analysis of wellbore retrofit potential and emission reduction in both fugitive gas abatement and flare gas. We selected the I-West region due to its abundant energy sources and oil and gas production legacy. Preliminary analysis hints that well retrofits can breathe new life into a well at a fraction of the cost of a new drill. With millions of potential candidates in the US, even a modest fraction (1% or less) suitable for retrofit could accelerate the shift to large-scale CO2 sequestration. Fugitive gas, the unintentional release of wellbore gases such as methane, is a significant emissions source. Through conservative analysis, it is estimated that wellhead leakage alone may account for 5 million tonnes of carbon dioxide equivalent (CO2e) emissions. We conclude by assessing the CO2 emissions from flaring, which is the burning of associated gas during well operations, conservative analysis indicates flaring contributes another 2 million tonnes of CO2 emissions to the region. We find that with targeted retrofit and better controls on emissions sources, the I-West region can make a significant impact in the nation's push to become net-zero. This study outlines economic feasibility and actionable items to achieve the critical reductions in emissions and increases in sequestration necessary to attain net zero.

Retrofit and application of pulverized coal burners with LNG and oxygen ignition in utility boiler under ultra-low load operation.

An oxygen-rich and low NOx burner integrated with liquefied natural gas (LNG) was proposed to address unstable combustion and high NOx emissions from a 330 MW subcritical boiler under ultra-low load operation in China. To assess the effectiveness of the retrofit, Chemkin and Fluent softwares were utilized to construct a new NOx model and calculate NOx generation, based on the combustion of pulverized coal gas and LNG. Further, an eddy dissipation concept (EDC) model, which can reflect detailed chemical reactions, was applied to calculate gas-phase reactions in the furnace. The results showed that when performing the deep peak shaving after the retrofit, the combustion in the furnace was stable under 50% or more load, and NOx emission level at the furnace outlet was lower than 350 mg/m3 (6% O2 content, dry basis). Under 25% load, the oxygen-rich burner integrated with LNG was applied, and the pulverized coal flow entered the furnace in a state of high-intensity combustion, which effectively promoted the stability of combustion in the furnace. The reductive combustion state with reductive free radicals generated by LNG decomposition inhibited NOx formation. Consequently, NOx emissions from the furnace outlet decreased from 380 mg/m3 to 316 mg/m3.

Urban residential building stock synthetic datasets for building energy performance analysis.

The urban building stock dataset consists of synthetic input and output data for the energy simulation of one million buildings. The dataset consists of four different residential types, namely: terraced, detached, semi-detached, and bungalow. Constructing this buildings dataset requires conversion, categorization, extraction, and analytical processes. The dataset (in .csv) format comprises 19 input parameters, including advanced features such as HVAC system parameters, building fabric (walls, roofs, floors, door, and windows) U-values, and renewable system parameters. The primary output parameter in the dataset is Energy Use Intensity (EUI in kWh/(m2*year)), along with Energy Performance Certificate (EPC) labels categorized on an A to G rating scale. Additionally, the dataset contains end-use demand output parameters for heating and lighting, which are crucial output parameters. jEPlus, a parametric tool, is coupled with EnergyPlus and DesignBuilder templates to facilitate physics-based parametric simulations for generating the dataset. The dataset can be a valuable resource for researchers, practitioners, and policymakers seeking to enhance sustainability and efficiency in urban building environments. Furthermore, dataset holds immense potential for future research in the field of building energy analysis and modeling.

Structural retrofitting of RC slabs using bamboo fibre laminate: Flexural performance and crack patterns.

Enhancing the durability of structural elements is a viable approach to promote sustainability in civil engineering. Research has shown that well-maintained slabs outperform degraded ones, which deteriorate rapidly due to insufficient upkeep. The occurrence of cracking and deformation in slabs subjected to sustained loads significantly impacts their functionality. However, the implementation of appropriate retrofitting techniques utilizing locally available materials can effectively minimize deflection and crack propagation while also improving flexural capacity. This particular study aimed to evaluate the flexural performance of slabs that were retrofitted using bamboo fibre laminate (BFL). Also, the study investigated two alternative replacement methods alongside the conventional mix; one involved replacing all fine aggregates with ceramic fine aggregate and the other involved a complete replacement of coarse aggregates with ceramic coarse aggregate. These mixes were represented in both the retrofitted and non-retrofitted samples. The retrofitting process included using the combined external bonding and near surface-mounted method. Twelve slab samples were made, with six being non-retrofitted and the other six retrofitted with BFL. Each of the samples had dimensions of 300 mm × 300 mm × 50 mm for reinforced concrete (RC) slabs. The slabs were tested employing the three point-bending system, and the retrofitted slabs with the conventional mix exhibited the highest ultimate failure load and flexural strength (62.1 kN), which compared to the non-retrofitted slabs of the same mix was a 60.76% increase. Additionally, the study did a thorough analysis of the presence of flexural and diagonal shear cracks, as well as the occurrence of debonding between BFL and the slabs. Non-destructive tests were also conducted on the slab samples to further confirm accurate results. These findings offer helpful insights into the development and application of a sustainable retrofitting material that can remarkably improve RC slabs.

Experimental Study of Reinforced Concrete T-Beam Retrofitted with Ultra-High-Performance Concrete under Cyclic and Ultimate Flexural Loading.

Structurally deficient bridges are commonly retrofitted using conventional methodologies, including reinforced concrete, steel jackets, and fiber-reinforced polymers. Although these retrofit methods aim to improve structural performance, exposure to aggressive environments may undermine the durability performance of the retrofit material. More recently, ultra-high-performance concrete (UHPC) has provided an alternative to conventional construction methods, with its superior material characteristics favoring its use in retrofit applications. In this study, a large-scale reinforced concrete (RC) T-beam is constructed and artificially damaged. The T-beam is then retrofitted with an external envelope of UHPC on all faces. Sandblasting is introduced to the surface, providing partially exposed reinforcement in the T-beam to simulate material deterioration. Additional reinforcement is placed in the web and flange, followed by casting the enveloping layer of UHPC around the specimen. The feasibility of this method is discussed, and the structural performance of the beam is assessed by subjecting the beam to cyclic and ultimate flexural loading. This paper presents the results of cyclic and ultimate testing on the RC-UHPC composite T-beam regarding load-displacement, failure mode, and strain responses. The retrofitted T-beam specimen is subjected to a cyclic loading range of 131 kN for 1.576 million cycles. Despite no visible cracks in the cyclic testing, the specimen experiences a 12.22% degradation in stiffness. During the ultimate flexural testing, the specimen shows no relative slip between the two concretes, and the typical flexural failure mode is observed. By increasing the longitudinal reinforcement ratio in the web, the failure mode can shift from localized cracking, predominantly observed in the UHPC shell, toward a more distributed cracking pattern along the length of the beam, which is similar to conventional reinforced concrete beams.

Application of Silica-Aerogel-Fibre-Based Thermal Renders for Retrofits in Building Walls: A Comparative Assessment with Benchmark Solutions.

The current climate change context raises the demand for reducing energy and environmental impacts while keeping an economic balance and building users' comfort. Thermal insulation solutions are potential allies in ensuring the adequacy of existing buildings for challenging sustainability requirements. In this scenario, silica-aerogel-fibre-based thermal renders are innovative solutions for which integrated approaches still lack information, and they should be compared with benchmark multilayer solutions, such as those based on expanded polystyrene (EPS), extruded polystyrene (XPS), mineral wool (MW), and insulated corkboard (ICB), to evidence their prospective economic, environmental, and energy benefits. This paper quantifies the optimum insulation thicknesses, life cycle savings, payback periods, and environmental impacts of innovative thermal renders compared to conventional thermal insulation materials when applied as a retrofit in existing facade walls. The results show that cost-optimised thermal renders with sisal fibres led to the best overall performance. Higher heating needs led to higher optimum render thicknesses and life cycle savings. With a 0.02 m thickness, aerogel-fibre-based thermal renders outperformed other materials in terms of heating-degree days (HDD) from 1000 °C·day onwards; they can save approximately EUR 60∙m-2, 1000 MJ∙m-2, and 100 kg CO2 eq∙m-2 while presenting a U-value 13% lower throughout their 30-year lifetime when compared with the second-best multilayer solution with XPS.

Current Trends in Aerogel Use in Heritage Buildings: Case Studies from the Aerogel Architecture Award 2021.

Silica aerogels are high-performance thermal insulation materials that can be used to provide unique solutions in the envelopes of buildings when space is limited. They are most often applied in historic buildings due to thin insulation thicknesses and since they are compatible with historic structures. In 2021, the first Aerogel Architecture Award was held at Empa in Switzerland in order to collect, evaluate and award outstanding uses of this relatively new building material. From the submitted projects, three were selected for an award by an expert jury. They showcased applications in which heritage protection and the conservation of a building's character and expression were reconciled with significant improvements in the energy efficiency of the building. The submissions also showed that a broader communication of these types of solutions is important in order to provide more information and security to planners and heritage offices and to facilitate the application of these materials in the future so that they can contribute to the protection of cultural heritage and reductions in the operational and embodied emissions of our building stock by extending the life expectancy and energy efficiency of existing buildings.

Energy financing, energy projects retrofit and energy poverty: a scenario-analysis approach for energy project cost estimation and energy price determination.

The research aims to determine the nexus of energy projects retrofit and poverty under two scenarios: energy project cost estimation and energy price determination. Households in rural areas of northern China are now required to switch from coal to cleaner heating options, including natural gas and electricity, as part of a government-led clean heating initiative. This initiative significantly increased the heating expense for participating homes, even when substantial subsidies were applied. We surveyed a large number of northern Chinese households to learn more about the rise in energy insecurity that has been attributed to government action. Our research shows that switching to electricity and gas from coal considerably worsens energy poverty in several ways, whereas switching to clean coal improves the situation. According to an econometric study, changes in energy poverty reveal heterogeneity in several ways. There is little change in Beijing, while the considerably less developed province of Hebei to the north sees a 75% rise. Energy poverty is more common in families with poorer incomes, lower levels of education, and smaller sizes. People who lack resources to insulate their homes will feel the effects more acutely. These results support the idea that low-income families would suffer disproportionately under a "one policy for all" mandate. For policymakers working on energy transition strategies for a low-carbon economy, it highlights the need to consider the distributional impact.

School building energy efficiency and NO2 related risk of childhood asthma in England and Wales: Modelling study.

BACKGROUND: Climate change legislation will require dramatic increases in the energy efficiency of school buildings across the UK by 2050, which has the potential to affect air quality in schools. We assessed how different strategies for improving the energy efficiency of school buildings in England and Wales may affect asthma incidence and associated healthcare utilization costs in the future. METHODS: Indoor concentrations of traffic-related NO2 were modelled inside school buildings representing 13 climate regions in England and Wales using a building physics school stock model. We used a health impact assessment model to quantify the resulting burden of childhood asthma incidence by combining regional health and population data with exposure-response functions from a recent high-quality systematic review/meta-analysis. We compared the effects of four energy efficiency interventions consisting of combinations of retrofit and operational strategies aiming to improve indoor air quality and thermal comfort on asthma incidence and associated hospitalization costs. RESULTS: The highest childhood asthma incidence was found in the Thames Valley region (including London), in particular in older school buildings, while the lowest concentrations and health burdens were in the newest schools in Wales. Interventions consisting of only operational improvements or combinations of retrofit and operational strategies resulted in reductions in childhood asthma incidence (547 and 676 per annum regional average, respectively) and hospital utilization costs (£52,050 and £64,310 per annum regional average, respectively. Interventions that improved energy efficiency without operational measures resulted in higher childhood asthma incidence and hospital costs. CONCLUSION: The effect of school energy efficiency retrofit on NO2 exposure and asthma incidence in schoolchildren depends critically on the use of appropriate building operation strategies. The findings from this study make several contributions to fill the knowledge gap about the impact of retrofitting schools on exposure to air pollutants and their effects on children's health.

Data-Driven Insights through Industrial Retrofitting: An Anonymized Dataset with Machine Learning Use Cases.

Small and medium-sized enterprises (SMEs) often encounter practical challenges and limitations when extracting valuable insights from the data of retrofitted or brownfield equipment. The existing literature fails to reflect the full reality and potential of data-driven analysis in current SME environments. In this paper, we provide an anonymized dataset obtained from two medium-sized companies leveraging a non-invasive and scalable data-collection procedure. The dataset comprises mainly power consumption machine data collected over a period of 7 months and 1 year from two medium-sized companies. Using this dataset, we demonstrate how machine learning (ML) techniques can enable SMEs to extract useful information even in the short term, even from a small variety of data types. We develop several ML models to address various tasks, such as power consumption forecasting, item classification, next machine state prediction, and item production count forecasting. By providing this anonymized dataset and showcasing its application through various ML use cases, our paper aims to provide practical insights for SMEs seeking to leverage ML techniques with their limited data resources. The findings contribute to a better understanding of how ML can be effectively utilized in extracting actionable insights from limited datasets, offering valuable implications for SMEs in practical settings.

A Wireless Sensor Network for Residential Building Energy and Indoor Environmental Quality Monitoring: Design, Instrumentation, Data Analysis and Feedback.

This article outlines the implementation and use of a large wireless instrumentation solution to collect data over a long time period of a few years for three collective residential buildings. The sensor network consists of a variety of 179 sensors deployed in building common areas and in apartments to monitor energy consumption, indoor environmental quality, and local meteorological conditions. The collected data are used and analyzed to assess the building performance in terms of energy consumption and indoor environmental quality following major renovation operations on the buildings. Observations from the collected data show energy consumption of the renovated buildings in agreement with expected energy savings calculated by an engineering office, many different occupancy patterns mainly related to the professional situation of the households, and seasonal variation in window opening rates. The monitoring was also able to detect some deficiencies in the energy management. Indeed, the data reveal the absence of time-of-day-dependent heating load control and higher than expected indoor temperatures because of a lack of occupant awareness on energy savings, thermal comfort, and the new technologies installed during the renovation such as thermostatic valves on the heaters. Lastly, we also provide feedback on the performed sensor network from the experiment design and choice of measured quantities to data communication, through the sensors' technological choices, implementation, calibration, and maintenance.

Green engineered mulch for phosphorus and metal removal from stormwater runoff in bioretention systems.

Phosphorus and metals in stormwater runoff are major causes of water quality degradation. Bioretention systems are increasingly implemented to improve stormwater quality and to better manage stormwater quantity. Many studies have focused on modifying the composition of the soil bed to improve pollutant removal. However, the pollutant removal performance of bioretention systems can diminish over time, such as when clogging of the media occurs. Sediment accumulation on the soil surface may inhibit infiltration into the soil bed, thus limiting pollutant removal. Soil replacement may be eventually required as pollutants accumulate in the soil. In this study, a green retrofit material, called green engineered mulch (GEM), was generated by coating regular wood mulch with aluminum-based water treatment residuals (WTR) via a simple and low-energy process (patent pending). The GEM was developed to serve as a green retrofit for bioretention systems to enhance the removal of phosphorus and metals from stormwater runoff. The GEM was placed in a rain garden in Secaucus, NJ, USA for 15 months, during which 12 storm events (ranging from 6.0 mm to 89.6 mm) were monitored. Runoff and infiltrate samples were analyzed for dissolved and total concentrations of phosphorus and metals, along with other key water quality parameters. The GEM significantly reduced (p < 0.05) the total concentrations of phosphorus and metals in stormwater infiltrate compared to the inlet, unlike the regular mulch. Minimal or no contact with the GEM resulted in no significant pollutant removal from surface runoff. No significant pollutant export from the GEM was observed. The spent GEM can be disposed of as non-hazardous waste in municipal landfills. This study demonstrates that the GEM is a safe and effective retrofit. Moreover, the GEM is a simple and economical retrofit solution that can be used in place of regular mulch in bioretention systems.

Seismic Behavior of Concrete Columns Retrofitted with a Brace-Type Replaceable Steel Link.

This paper presents the results of a combined cyclic loading test on a single reinforced concrete column which was retrofitted with a newly proposed brace-type replaceable steel link. A total of four retrofitted reinforced concrete columns, with the length of the brace as a variable, were fabricated and tested. A companion column without retrofitting was used as the control specimen. The test results indicate that the proposed brace-type replaceable steel link can be effective in retrofitting the concrete columns, resulting in improvements in the strength, stiffness, and energy dissipation of columns. We observed that the maximum load increases by at least 87%, effective stiffness increases by 44%, and energy dissipation capacity increases by 91% when compared with non-retrofitted specimen.

A Design Process for Preventing Brittle Failure in Strengthening RC Slabs with Hybrid FRP-HPC Retrofit Systems.

The retrofitting of existing RC slabs with an innovative system comprising FRP and HPC has been demonstrated to be effective in strengthening and overcoming the logistical challenges of installation. Nonetheless, the excessive improvement of flexural strength over shear strength would cause the sudden failure of rehabilitated flexural members. The literature has previously recommended failure limits to determine the additional moment strength compared with the shear strength to prevent brittle shear failure of strengthened, continuous RC slabs. This study suggests a design process for preventing shear failure and inducing the ductile-failure mode to improve the safety and applicability of retrofitted RC slabs based on the proposed failure limits. The effectiveness of the procedure in brittle-failure prevention for the end and interior spans of retrofitted RC slabs is illustrated via a case study. The outcomes showed that the retrofit system with 0.53-mm-thick-CFRP prevented brittle failure and significantly enhanced the design-factored load and ultimate failure load by up to 2.07 times and 2.13 times, respectively.

Evolutionary dynamics of homeowners' energy-efficiency retrofit decision-making in complex network.

Understanding homeowners' energy-efficiency retrofit (EER) decision-making is a critical priority for reducing the adverse environmental impacts of the building sector and promoting a sustainable consumption transition. Existing research lacks attention to the dynamics and social interactions in the decision-making process of homeowner EER adoption. This paper applies the complex network-based evolutionary game approach with agent-based modeling to construct an evolutionary dynamics model for homeowners' EER adoption decision-making. Through simulation experiments, this paper examines the effects of various key factors, including government incentives, retrofit costs, retrofit uncertainty, and network size, on the evolution of EER adoption. The results suggest that government incentives facilitate EER adoption, but their effects require a sufficiently long period of policy implementation and extensive social interaction to be realized. Reducing retrofit costs is a robust and effective way to encourage EER adoption, especially when uncertainty is high. Retrofit uncertainty has a significant impact on the adoption evolution. Increased uncertainty can hinder adoption decisions. In particular, the combination of high uncertainty and incentives is prone to lead to incentive failure. The increase in network size contributes to EER adoption, but attention needs to be paid to the impact of potential incentive redundancy in large-scale networks.

Estimation of the effect on air quality of retrofitting SCRT on urban buses in Copenhagen.

This study estimates the effect on air quality of retrofitting SCRT on about 300 urban buses in Copenhagen from September 2015 to March 2016. The retrofitted buses were of Euro III, Euro IV and EEV emission standards. The specific SCRT technology applies ammonia as injected into the exhaust as a gas as opposed to normally as a liquid (urea). This technology is more efficient in reducing NOx emissions, especially under urban driving conditions with relatively low exhaust temperatures. The estimation of the effect is based on air quality model calculations for 98 selected busy streets in Copenhagen for 2015 based on, among others, information from the Zealand public transport agency about buses with and without retrofitted SCRT. More detailed analyses were conducted for two of the streets where fixed air quality measuring stations are located in Copenhagen. Furthermore, a before-after analysis of the development of measured concentrations at fixed measuring stations was carried out to isolate the effect of the retrofitted SCRT. The model calculations showed substantial reductions in emissions of NOx and exhaust particles from each bus (90%) but low reductions in concentrations of NO2, PM2.5 and PM10, respectively 3% for 98 streets on average for NO2, and 0.1%[0.2%] for PM2.5 and 0.07%[0.1%] for PM10 for H.C. Andersen Boulevard and [Jagtvej]. Based on the analysis of trends in the measurements it was not possible to isolate an effect of SCRT on urban buses in Copenhagen probably due to the large variations in meteorology affecting the variations in concentrations.

Transporting offshore wind power in the Western Gulf of Mexico: retrofitting existing assets for power transmission via green hydrogen-a review.

The USA recently announced it is planning on deploying 30 GW of offshore wind by 2030 (national goal for offshore wind). Part of this development will be in the Gulf of Mexico, which has both wind potential and pre-existing oil and gas pipelines, only a portion of which is currently being used. Examining whether these assets can be used to economically transport power back from future Gulf wind farms should be a first step for developers. The question of whether laying new high-voltage direct current submarine cable versus repurposing pipeline to transport wind power will be examined. This paper looks at the hydrogen market and its use to transport wind power, what it would take to retrofit pipeline to carry hydrogen, a cost analysis given available data, and a look at potential policy support. There is a need to assess pipelines individually; however, retrofitting existing infrastructure should be considered an alternative to laying new submarine transmission cables. Additionally, alleviating the issue of oil and gas stranded assets through pipeline reuse may provide political support in hastening the energy transition.

Role of housing in blood pressure control: a review of evidence from the Smart Wellness Housing survey in Japan.

Current countermeasures for preventing hypertension emphasize only improvements to lifestyle. Recently, improving life environment has attracted attention, in parallel with publication of the WHO Housing and health guidelines. We quantitatively evaluated the relationship between housing thermal environment and blood pressure (BP) in a real-world setting. We conducted a nationwide, prospective intervention study-the Smart Wellness Housing survey-in Japan, as a non-randomized controlled trial. The intervention was the retrofitting of thermal insulation in houses. Participant recruitment was done by construction companies in all 47 prefectures of Japan. Measurements of home BP and indoor temperature at 1.0 m above the floor in the living room, changing room, and bedroom were taken for 2 weeks before and after the intervention each winter (November-March) of FY 2014-2019. As of July 2022, over 2500 households and 5000 participants were registered in the database. We found that (1) about 90% of Japanese lived in cold homes (minimum indoor temperature <18 °C), (2) indoor temperature was non-linearly associated with home BP, (3) morning systolic BP (SBP) was more sensitive than evening SBP to changes in indoor temperature, (4) SBP was influenced by indoor temperature change particularly in older participants and women, (5) unstable indoor temperature was associated with large BP variability, and (6) insulation retrofitting intervention significantly reduced home BP, especially in hypertensive patients. We proposed that the BP reduction effect of the life-environment is comparable to that achievable by lifestyle.

Radon levels and indoor air quality after application of thermal retrofit measures-a case study.

This study was conducted to evaluate the influence of thermal retrofit on radon levels in workrooms, and to determine whether the radon concentration in the building changes after the application of retrofit measures. In the first survey, digital Airthings Corentium Home radon detector was used for 1-month radon measurements during the heating season 2018/19. The daily averaged radon concentrations varied from 37 to 573 Bq/m3 for 10 selected workrooms, while hourly averaged radon measurements showed extreme variations from 6 to 1603 Bq/m3 due to radon fluctuations. In second survey, passive radon technique based on charcoal canister test kit was conducted in all basement workrooms in spring 2021. The averaged radon concentrations grouped according to flooring type in workrooms were 327 Bq/m3 for parquet, 227 Bq/m3 for ceramic tiles, 146 Bq/m3 for vinyl flooring and 71 Bq/m3 for laminate. Besides thermal insulation and airtight windows, noticeable differences in indoor radon concentration within the renovated building are primarily caused by different types of flooring. It includes various types of insulation from the ground/concrete slab: laminate, parquet (wood blocks), vinyl flooring, and ceramic tiles. Detailed analysis point out that laminate is more efficient way for radon protection than other types of flooring. An efficient ventilation system should be installed to avoid increasing occupational radon exposure and to provide healthy and comfortable indoor environment.