Local Thermal Discomfort Research Articles

Allowable surface temperature of ceiling heating based on radiant temperature asymmetry

Radiant temperature asymmetry as one of the criteria for local thermal discomfort has an influence on the practical design of the heating system, as people are most sensitive to the radiant heating of the top of the head. The paper presents the determination of the allowable surface temperature of the heated ceiling based on the theoretical calculation using the angle factors and taking into account the allowable the radiant temperature asymmetry according to the standard values of 5 and 7 K. In practice, the radiation temperature asymmetry is determined by measuring two radiant temperatures. In this paper, the measurement of radiant temperature asymmetry is measured in an experimental room with a heated ceiling and the results are compared with the theoretical calculation procedure. The paper points out the differences between the measured and calculated values of the radiant temperature asymmetry. Based on the analyses, the allowable ceiling temperatures for radiant heating have been determined for different room geometries so that the radiant temperature asymmetry for thermal comfort categories A, B is actually observed. A new correlation has been established to determine the allowable surface temperature of the radiant ceiling as a function of the angle factor between the small plane element and the ceiling. For practical use, the correlation has been adjusted for typical geometric cases without the need for calculation of angle factors. Maximum ceiling surface temperatures are graphically displayed without causing thermal discomfort. Conversely, in large rooms with a heated ceiling, the ceiling surface temperature is severely limited, precisely because of the potential for thermal discomfort due to radiant temperature asymmetry.

Prediction on Chinese elderly's thermo-physiological and cardiovascular responses to non-uniform and transient thermal environment during getting-up process

Getting-up process after sleep would typically involve the non-uniform transition with temperature reduction, increased activity level, and change in clothing insulation, which is rarely explored in existing research. Due to the decline of physiological adaptability of the elderly, they may have sudden changes in physiology under transient environment. It is necessary to develop prediction models for the elderly to prevent or reduce health risks. The aim of this research is to predict the thermo-physiology and cardiovascular responses to non-uniform and transient thermal environments during getting-up process, a 4-node thermoregulatory-cardiovascular predicted model was established based on Gagge's thermoregulatory and heart rate model in International Organization for Standardization. Experimental data of twenty-six Chinese elderly subjects aged over 60 at a caring home in Chongqing both in winter and summer conditions was collected for validating. The results showed that the non-uniformity and dynamic states were 5.0–15.0 °C temperature differences between cover and bedroom. Core and overall skin temperatures decreased by 0.1–0.3 °C, while the heart rate increased by 5–10 %. Bare skin temperature decreased significantly by 0.2–1.0 °C. It implied that the process posed a potential risk to body cooling, local thermal discomfort, and cardiovascular health in the elderly, which was more severe in winter. The prediction result's error was below 6.0 %, which was more accurate by 6.0 %–18.0 % than that of typical models. This research can provide a reference for creating comfortable and healthy bedroom temperatures after sleeping for the elderly by intelligent air conditioning at residences and care homes.

Indoor thermal environment assessment of a historic building for a thermal and energy retrofit scenario using a CFD model

Research on retrofit scenarios for the energy efficiency of historical buildings is growing. Despite their potential to improve the energy consumption of a building, retrofit scenarios for indoor thermal environments and the thermal comfort of historical buildings has not been sufficiently studied. Therefore, in this study, indoor airflow, heat distribution, and thermal comfort levels of indoor residents were predicted using computational fluid dynamics (CFD) modeling of historic buildings based on measured values. Although the heating was turned on in the meeting room in winter, heat loss caused by low thermal performance, airtightness, and inflow of cold air caused local thermal discomfort. Individuals seated near the windows had a temperature difference of up to 2.6 °C between the head and ankle levels. Heat loss was identified from the exterior walls and windows, with air infiltration significantly affecting indoor thermal comfort. The airtightness of the window frames of historic buildings was low, thus necessitating related improvement in heat and energy retrofit scenarios. This study propose a suitable approach to resolve this problem.

Study of indoor local thermal comfort for impinging jet ventilation combined with ductless personalized ventilation under different cooling loads

Excessive temperature stratification and draught are two prominent drawbacks for impinging jet ventilation (IJV). Using IJV together with ductless personalized ventilation (DPV) (i.e., IJV + DPV) has been proved to be an effective way to reduce temperature stratification, but the draught rate around occupant would be increased. In the current work, an in-depth study on the characteristics of indoor local thermal comfort for IJV + DPV operating with different scenarios is done. Predictive models for the local thermal comfort indicators are developed to optimize the operating parameters (including supply velocity of IJV (Vs) and intake airflow rate of DPV (Df)) with different room cooling loads (Q). The results show that the application of IJV can be extended to spaces with high cooling loads (e.g., larger than 60 W/m2) by using together with DPV, but the risk of thermal discomfort increases. To avoid local thermal discomfort, the combination relationship between Vs and Df should be properly matched and this relation becomes more stricter with the increase of Q. It also obtains that the maximum cooling load that IJV + DPV can eliminate is less than 170 W/m2. At last, to ensure the IJV + DPV create a good local thermal comfort environment, design chart about the feasible ranges of Vs and Df are established for different values of Q. On the whole, the current study not only can provide a basis for the application of IJV + DPV in spaces with high cooling load, but also can provide theoretical guidance for the operation control and optimization design of the IJV + DPV.

Parks may not be effective enough to improve the thermal environment in Shanghai (China) as our modified H3SFCA method suggests

Anthropogenic warming and rapid urbanization have exacerbated the deterioration of urban thermal environments, increasing interest in the ability of parks to regulate local climates. However, their potential to mitigate local thermal discomfort and spatial mismatch in supply and demand is poorly understood. We 1) examined the cooling effects of Shanghai's parks via a thermal comfort index, 2) identified the role of parks in improving local thermal environments by comparing thermal discomfort and park cooling capacity, and 3) explored the spatial mismatch between the demand for thermal discomfort mitigation and the supply of park cooling based on multiple park accessibility. The extent of park cooling is inversely related to the level of urbanization, while cooling intensity is positively associated with urbanization. Only 20.65% of the parks effectively mitigate local thermal discomfort, highlighting the need for improvements. Cooling accessibility increases from the city center to the periphery, with 22.70% of areas lacking access to park cooling services within a 15-min radius. Further improvements can enhance the thermal comfort of accessible parks by 49.55%. Priority adaptation is required in old urban areas and key development zones in peripheral urban areas to meet the needs of their large populations. Our study contributes to the study of urban thermal discomfort mitigation via parks in the context of climate adaptation planning.

Subjective perceptions of 8, 11 and 14°C chemotherapy liquid cooled gloves and socks

We investigated the effects of peripheral cooling using chemotherapy gloves and socks at three cooling temperatures on subjective perceptions. The hands and feet were cooled with 8, 11, and 14°C by water-perfused gloves or socks. Nine females participated in six experimental conditions: hands or feet cooling at 8, 11, and 14°C. The heat was extracted at 3.8, 5.4, and 7.7 kJ·min1 via the gloves and at 4.1, 6.0, and 9.0 kJ·min-1 via the socks. While the results showed that overall subjective perceptions did not differ among the three temperatures (~ 9.0 kJ·min-1), there were significant differences in local thermal comfort, pain sensation, and pain discomfort among the three cooling temperatures (P < 0.05). When cooling the hands or feet at 8, 11 or 14°C, subjects felt ‘cold’ or ‘cool’, on average, at the end of 60-min cooling with no significant differences among the three temperatures, whereas subjects felt more uncomfortable at 8°C than 14°C for cooling either the hands or feet (P < 0.05). Subjects felt more pain at 8°C than 14°C cooling for both hands and feet. These results indicate that the 8°C cooling for 60 min might cause uncomfortable pain sensation, especially for cold-vulnerable individuals. We recommend 1) a cooling bout of less than 60 min, 2) a cooling temperature higher than 8oC when cooling the hands or feet, and 3) a higher temperature for the feet when the hands are simultaneously cooled. However, the present results on subjective perceptions should be interpreted with peripheral vasoconstriction of fingers and toes while cooling.

Addressing personalized thermal comfort in residential settings: A novel dual-supply vent air conditioner

A new approach was proposed for meeting diverse thermal comfort demands of different occupants by using a dual-supply vent air conditioner with independent control of the air supply parameters at each vent to establish distinct thermal environments. The feasibility of this method was tested in a living room environment, and numerical simulation was conducted to explore the differences in thermal environment at various locations under different air supply temperatures, velocities, directions, and vent positions. The results indicated that, within the targeted air supply zone, the maximum temperature difference could reach around 2.5 °C. Considering the Cooling Effect of air velocity, the maximum Equivalent Temperature difference was around 4.5 °C, which could address the differences in common personalized thermal comfort preference. Utilizing the differential air supply velocities of different vents was an effective means of achieving diverse thermal environments, although attention should be paid to local thermal discomfort caused by drafts. This approach may offer a new perspective in addressing the differing thermal comfort preferences among occupants within the same residential room, additionally providing innovative insights for improving traditional air conditioning systems.

Experimental study of draft-related local discomfort in a room with stratum ventilation

Given increased air movement in rooms with stratum ventilation, draft may be a major cause of local thermal discomfort. However, there was a lack of comprehensive study on the draft risk of stratum ventilation and its causation. Hence, this study systematically conducted the subjective assessment of draft and examined its influencing factors in a stratum-ventilated room. Thermal sensation, preferences for air movement and air temperature, as well as thermal acceptability were surveyed. The subjects were exposed to different combinations of supply airflow rate and room air temperature, which created thermal conditions from slightly cool to slightly warm. Results showed that compared with supply airflow rate, room air temperature exerted more significant effects on the subjective responses to air movement. Regarding draft sensation, the upper body segments were more susceptible to supply airflow rate and room air temperature than the lower body segments. For room air temperature of 24 °C, the slightly cool sensation resulted in high draft rates, while room air temperature of 26 °C and above could significantly decrease draft risk. Air movement preference was closely correlated to overall thermal sensation. An overall thermal sensation value of −0.4 was found to be the lower limit to provide a draft rate less than 20%, and a value of −0.1 was the most desired overall thermal sensation as a majority of subjects wanted air movement to remain unchanged. Taking both the preferred air movement and temperature into account, room air temperature of around 26–27 °C was recommended to achieve satisfactory thermal environment.

Numerical investigation of thermal-humidity environment in pedestrian area of ecological community with the porous pavement in arid areas

In this paper, the water evaporation from porous pavement is used to improve the thermal-humidity environment (THE) in pedestrian area of ecological community at the large wind and sand, and arid areas, such as Lanzhou in northwest China. A simulation model is established to analyze the THE of ecological community with the porous pavement in arid areas. And the water evaporation is considered from plant transpiration and porous pavement in this model. The simulation results are compared with the experimental results, the relative error was less than 13.5%. At the same time, the THE is also analyzed under different building layout, building spacing and building height. The results show that the average value of universal thermal climate index (UTCI) in pedestrian area increases with the building height, while the minimum value has little difference. This means that the local thermal discomfort would more likely occurs in ecological community with the building height increase. The local value of UTCI in pedestrian area decreases by about 8℃ when the building spacing is changed from 10 m to 40 m. The uniformity of UTCI is greatly improved when the building spacing rises to 25 m. The array building layout should be adopted in Lanzhou, the building spacing should be at least 25 m when the building height is 50 m. The above research results can provide theoretical guidance for improving the thermal comfort level of ecological community in Lanzhou.

A local thermal sensation model suitable for thermal comfort evaluation of sensitive body segments

Nowadays, an indoor environment is created by heating, ventilation, air-conditioning, and cooling (HVAC) systems that meet the cooling needs of occupants in summer, however, local thermal discomfort (like joint discomfort) is widespread. Existing studies have focused on local thermal sensation models to predict the thermal comfort of non-sensitive body segments (like the forehead) but only a few reports have focused on the thermal sensation of sensitive body segments. The existing models cannot be directly applied to predict the thermal comfort of sensitive body segments (joints). To address this problem, the present investigation first assessed the correlation between the thermal sensation voting (TSV) of sensitive and non-sensitive body segments. Subsequently, this study established a local thermal sensation model based on the skin temperature to evaluate the thermal sensation of body segments, especially the sensitive segments (joints). In the proposed model, the sensitivity coefficient, k, and the cold tolerance coefficient, c, were introduced. The k value represented the sensitivity of the body segments, while the c value reflected the point whereby the body segment began to significantly feel cold. By changing the k and c values, different local characteristic curves across body segments were obtained. Finally, this research validated the accuracy of the proposed model, and its prediction accuracy was within 15% when the deviation of TSV was ±1. Thus, the proposed local thermal sensation model could be applied for adjusting indoor parameters, and meeting local thermal needs on demand is the key to exploring the relationship between humans and the environment.

Improving indoor thermal and energy performance of large-space residential buildings via active approaches

Improving the indoor thermal and energy performance of residential buildings plays a significant role in the low-carbon goals of building industry. Residential buildings usually utilize the active approaches, such as air conditioning and radiant floor. A large-space residential building that removes partial second floor can employ the retractable membrane ceiling to control building indoor performance. These active approaches can be combined to ensure thermal comfort and save energy of large-space residential buildings. Therefore, this study carries out a series of experiments to quantify the individual and combined effects of retractable membrane ceiling, air conditioning and radiant floor.The dual-approach and triple-approach experiments combine two and three from the retractable membrane ceiling, air conditioning and radiant floor. It is obtained that the membrane ceiling/air conditioning can effectively improve indoor thermal performance. The energy consumptions for air conditioning and membrane ceiling/air conditioning are 1.14 kWh and 0.89 kWh at an air temperature of 25 °C. The triple-approach experiments can solve the local thermal discomfort caused by the low air movement since the radiant floor accelerates the local air movement. The comparisons of temperature difference, air velocity and energy consumption for single-approach, dual-approach and triple-approach demonstrate that the retractable membrane ceiling is an efficient method to improve indoor thermal and energy performance of large-space residential buildings.

Local thermal comfort chart for non-uniform building environments: Comparison with vehicle environments and its application

There have been many laboratory studies of human subjects exposed to non-uniform thermal environments such as radiant temperature asymmetry from different directions, vertical air temperature differences, and draught. However, there are no final conclusions on the unified quantitative index for general non-uniform environments, which will be stressed in this study. The equivalent temperature (teq) that integrates air temperature, radiant temperature and air velocity at different body parts and well relates with thermal perceptions is adopted as an integral evaluation index. Published data from laboratory measurements of office environments with subjects exposed to different types of radiant asymmetry and measurements with a thermal manikin were analysed. A new comfort chart of teq was developed to evaluate non-uniform building environments and it was compared with the existing comfort chart (in ISO 14505) applied in vehicle. The results indicated that overall sensible heat loss of the human body remained constant, but local thermal discomfort and sensation changed with the non-uniform environments. The new comfort chart identified the source of discomfort and predicted the observed subjective evaluations. Significant discrepancy of the comfort chart between buildings and vehicles was found, indicating the necessity of developing a comfort chart that applied in the building environment. The study provides new insights into the causes of local thermal discomfort and can provide information on the sensitivity of different body parts to heat loss that can be used to optimise the thermal design of indoor environments.

Experimental Investigation of Indoor Thermal Comfort under Different Heating Conditions in Winter

Owing to historical reasons, only a few locations in the Guangdong province use heating to enhance interior thermal conditions. With the variation in climate and increase in people’s lifestyle requirements, winter heating has become increasingly necessary. However, a literature review revealed that only a few studies have investigated the heating requirements during winter in the Guangdong province. In this study, we compared the thermal comfort of radiant floor heating with wall-mounted air conditioner heating. A Guangzhou University climate chamber was used in several investigations. The findings revealed that the thermal neutral temperatures of radiant heating and air conditioner heating were 22.0 °C and 23.0 °C, respectively, about 1 °C variation in temperature. Additionally, in the research on thermal reactions and local skin temperature measurements, the impact of local thermal discomfort on the overall thermal experience was also considered. The findings showed a direct relationship between the local thermal discomfort caused by radiant heating and general thermal sensation. Thermal sensation of the subjects mainly originated from the lower extremities and was significantly affected by Va (air velocity). The relationship between the local thermal discomfort of convective heating and general thermal sensation was weak and mainly caused by the uneven thermal environment. Thus, in south China, for lowering energy usage, radiant floor heating should be used to create an improved indoor thermal environment in winter.

A Multi-Segmented Human Bioheat Model for Asymmetric High Temperature Environments.

In workplaces such as steel, power grids, and construction, firefighters and other workers often encounter non-uniform high-temperature environments, which significantly increase the risk of local heat stress and local heat discomfort for the workers. In this paper, a multi-segment human bioheat model is developed to predict the human thermal response in asymmetric high-temperature environments by considering the sensitivity of the modeling to angular changes in skin temperature and the effects of high temperatures on human thermoregulatory and physiological responses simultaneously. The extended model for asymmetric high-temperature environments is validated with the current model results and experimental data. The result shows that the extended model predicts the human skin temperature more accurately. Under non-uniform high-temperature conditions, the local skin temperature predictions are highly consistent with the experimental data, with a maximum difference of 2 °C. In summary, the proposed model can accurately predict the temperature of the human core and skin layers. It has the potential to estimate human physiological and thermoregulatory responses under uniform and non-uniform high-temperature environments, providing technical support for local heat stress and local thermal discomfort protection.

Demand-oriented differentiated multi-zone thermal environment: Regulating air supply direction and velocity under stratum ventilation

Different thermal preferences from occupants in a shared space must be satisfied simultaneously. For a ventilated room with multiple air supply inlets, differentiated thermal environment parameters can be maintained in different subzones by liberating the unified air supply parameter adjustment from all the air supply inlets and subsequently adopting independent adjustment of different groups of air supply inlets near different subzones. In this study, the achievable difference level of thermal environment was investigated numerically based on the stratum ventilation. Primarily, the effect of independently regulating the air supply directions and velocities from two inlet groups on the difference in the local thermal environment between subzones was analyzed. The position of occupants and heat distribution were considered as the influencing factors. Further, the predicted mean vote (PMV) index was utilized to evaluate the cool or warm degree of the local thermal environment while the draught rate (DR) and percentage dissatisfied (PD) indices were utilized to evaluate the local thermal discomfort. The results obtained indicated that regulating air supply direction significantly affected the differentiated thermal environment, with the achievable ΔPMV between subzones up to 1.46. Moreover, the increase in air supply velocity based on the appropriate air supply direction further expanded the ΔPMV. In addition, the change in heat source position resulted in a ΔPMV decrease of 0.36. No strong draught risk and local thermal discomfort caused by the vertical temperature difference were observed. This study is expected to provide guidance for the maintenance of demand-oriented zoning thermal environment.

Comfort limit for asymmetric thermal radiation from a cold wall in neutral to cool environments

Asymmetric thermal radiation from a cold surface, could easily cause local thermal discomfort and even health problems, such as knee osteoarthritis. An experiment with subjects was conducted to study the radiant asymmetry caused by a cold wall at a room temperature of 18 °C, which is the lower limit of the room temperature for heating design in Chinese Building Regulations. The temperature of a single wall was set at 15 °C and 12 °C respectively to simulate a cold exterior wall or window. A control experiment was also conducted under uniform chamber conditions. Groups of 24 healthy college students participated in the experiments. During the first 30 min of the 90-min experiment, the participants could adjust their clothing to approach thermal comfort. The skin temperatures and thermal perceptions of the subjects were measured. The results indicated that clo-value for participants increased with the decrease of the temperature of the cold wall. The skin temperatures and thermal sensations of the limbs were significantly lower than these of the upper torso. The skin temperature of the calf was the lowest. The prolonged exposure to the cold wall decreased the acceptability of the subjects. Accepting 5% of the subjects expressed local discomfort, the acceptable radiant temperature asymmetry was 4.2 K. The limit value obtained in this experiment was significantly lower than the limit value recommended in the existing standards. The lower acceptable value of radiant temperature asymmetry from this study can provide a relevant input to a revision of existing thermal comfort standards.

Effectiveness of personal comfort systems on whole-body thermal comfort – A systematic review on which body segments to target

Personal comfort systems (PCS) promise individualized thermal comfort, energy-savings and may even contribute to health by locally heating/cooling specific body segments. To date, however, insights into PCSs’ specific design guidelines or their effectiveness on whole-body thermal comfort are scarce. The fundamental question on which body segments should be targeted has not yet been answered. This paper attempts to answer this question by systematically reviewing studies on PCSs’ effects on local body segments and the whole body restricted to office scenarios.The results imply that the local thermal discomfort distribution over the body determines the PCSs’ effectiveness and that PCSs should eliminate local thermal discomfort by targeting it directly or indirectly. In a typical office scenario, local cooling may affect thermal perception in non-targeted body segments, however local heating may not. Therefore, PCSs could heat uncomfortable body segments directly in cold environments while indirect cooling may also effectively relieve discomfort in warm environments. Moreover, moderate local conditioning does not affect skin temperatures in most non-targeted body segments. The findings suggest that human thermoregulation may be stimulated, and hence, benefit our health, without compromising thermal comfort. Directions for future PCS design are proposed to bridge thermal comfort, energy-efficiency and health in offices.

Thermal environment investigation of asymmetric radiation coupled with convection heating.

The couple of radiation with convection heating owned advantages of less energy utilization, healthier and more comfortable indoor environment. However, local thermal discomfort was often induced by large vertical temperature difference and radiation asymmetry temperature. This work studied indoor thermal environment characteristics under different coupling ways of radiation and convection heating terminals through experiments and CFD simulation. The studied five scenarios were denoted as: (I) lateral air supply + adjacent side wall radiation, (II) lateral air supply + opposite side wall radiation, (III) lateral air supply + floor radiation, (IV) lateral air supply + adjacent side wall radiation + floor radiation, and (V) lateral air supply + opposite side wall radiation + floor radiation. The overall thermal comfort indices (including air diffusion performance index (ADPI), predicted mean vote (PMV), and predicted percent of dissatisfaction (PPD)) and local thermal comfort indices under different scenarios were investigated. For Scenarios I–III, the local dissatisfaction rates caused by vertical air temperature difference were 0.4%, 0.1%, and 0.2%, respectively, which belonged to “A” class according to the ISO-7730 Standard. While the vertical asymmetric radiation temperature of Scenario I/II was about 6.5 °C lower than that of Scenario III/IV/V. The ADPI for Scenarios III–V were about respectively 5.7%, 16.7%, and 21.0% higher than that of Scenarios I–II, indicating that a large radiation area and radiation angle coefficient could reduce the discomfort caused by radiant temperature asymmetry. The coupling mode improved local discomfort by decreasing vertical temperature difference and radiation asymmetry temperature wherefore improving the PMV from −1.6 to −1. The lateral air supply coupled with asymmetric radiation heating could potentially improve the thermal comfort of occupied area, while the comprehensive effect of thermal environmental improvement, energy-saving, and cost-effectiveness needes to be further investigated.

Field investigations on operational performance of a novel radiant floor heating equipment applied in a typical office building

Low-temperature radiant heating systems are widely used in buildings with significant energy conservation, and they are convenient for the utilization of low-grade energy resources and household metering. In this study, the practical application of a novel radiant floor heating system (RFHS) in cold regions is investigated via construction of an experimental platform for energy consumption and thermal comfort in an office building in Tianjin, China. The results indicated that the novel radiant floor exhibits higher heating capacity and heat transfer coefficient than that of a traditional radiant floor. During the experiment, the average indoor temperature was 25.0°C in the office room and 22.7°C in the conference room, and all instantaneous indoor temperatures exceeded 21°C. To avoid local thermal discomfort, the supply water temperature of the floor can be appropriately decreased by 2–3°C for operation. Additionally, the power consumption of the system is decreased by approximately 11.4% if the indoor temperature is decreased to 20°C. Hence, a 10-h operation mode per day can be adopted in the office building for energy conservation given that the novel radiant floor exhibits superior initial response to intermittent operation. Practical application: In this study, the practical application effect of a new type of water-passing floor is examined in cold regions to provide a design reference for engineering applications. Therefore, it is expected that the results will be helpful to researchers for indoor environments, heating, ventilating, and air conditioning engineers, system manufacturers, and those who want to analyze the operational performance of a radiant floor heating system.

ASHRAE Likelihood of Dissatisfaction: A new right-here and right-now thermal comfort index for assessing the Likelihood of dissatisfaction according to the ASHRAE adaptive comfort model

The assessment of local and short-term thermal discomfort in buildings has been widely investigated, and different metrics are available in the literature to predict the likelihood of dissatisfied people. These metrics are named right-here and right-now discomfort indexes and constitute the basis for evaluating long-term thermal comfort conditions in buildings. Well-known examples are the Predicted Percentage of Dissatisfied (PPD) part of the Fanger comfort model included in the ISO standard 7730 and the Overheating risk index (NaOR), built upon the EN adaptive thermal comfort model. This study proposes a new index for use with the ASHRAE adaptive thermal comfort model to fill a gap in the literature and standard. It is called the ASHRAE Likelihood of Dissatisfaction (ALD) and is obtained from a logistic regression of the right-here and right-now thermal comfort field data contained in the 1990s ASHRAE RP-884 database. The recent release of another, more extensive database of thermal comfort field studies, the ASHRAE Global Thermal Comfort Database II, provides an opportunity to validate ALD with an independent dataset and assess its generalisability. The successful external validation of ALD and its agreement with NaOR give support to the reliability of the novel right-here and right-now index and open to the possibility to use it for assessing short-term thermal comfort conditions in buildings, calculating long-term thermal comfort indices based on the ASHRAE adaptive model, optimising both the design of new buildings and renovations and for assessing the operational thermal comfort performance of existing buildings.