Winter Environment Research Articles

Thermal comfort of motion and stationary states for recreational spaces of colleges and universities in the cold regions of China

This study examined a representative college activity centre in China’s cold regions and conducted a field measurement study and questionnaire analysis on the indoor thermal environment in winter. Data fitting and comparative analysis were performed on the predicted mean vote (PMV) calculated from measured environmental parameters and the seven-point vote value actual mean vote (AMV) based on the questionnaire. According to the least square method, the corresponding human adaptive coefficient λm in the motion state and λs in the stationary state were obtained. Based on the research, the thermal comfort survey results were reported for the two states for recreational spaces of colleges and universities. These results suggest that the AMV and PMV do not coincide in the two states. The actual thermal sensation is less sensitive than predicted through the sensitivity analysis for the two states. The respondents’ actual thermal sensation is less sensitive when exercising than stationary state. Moreover, both PMV and AMV in motion state are higher than those in stationary state, illustrating that the state of motion has a greater influence on thermal sensation. This research provides a theoretical basis and data reference for the low energy design of recreational spaces of colleges and universities.

A Study on the Improvement of Double-Skin Facade Operation for Reducing Heating Load in Winter

A double-skin facade makes it possible to gain irradiance through the glass on the outer side in summer, and to increase the temperature of air flowing in the cavity so as to induce the flow of air current. Therefore, a double-skin facade is able to reduce the load of the outer skin, which is delivered from the outside to the inside in summer, and to serve as a buffer space for the internal and external environments in winter, and thereby prevent heat loss from the building envelope. Theoretical analysis was conducted to review the heat effects of a double-skin facade and to evaluate the performance of a plan for indoor load reduction. This study carried out a field measurement of a building with a double-skin facade and then analyzed the thermal phenomenon occurring in between the outer skin of the outside and the skin of the inside facing the building surface, according to the effects of irradiance going into the double-skin facade cavity. In order to propose an indoor air conditioning energy reduction plan using preheated air through the double-skin facade, this study utilized a building simulation to be implemented on the target building and then analyzed the effects of the improvement plan for the double-skin facade. A simulation model was suggested that implemented the aforementioned airflow network and analyzed the ventilation performance and energy performance according to the application of alternative plans and thermal effect. To find the actual state of operation of the double-skin facade in winter, this study measured the target building. A solar chimney-based double-skin facade was analyzed in winter. As a result, with the application of a solar chimney and a rise in its height, the available capacity of relatively larger solar heat increased, and therefore the proposed plan had excellent performance in terms of heating energy saving. When the thermal effect was applied to the solar chimney, the heating energy use effect of the solar irradiance of the double-skin facade was larger. When thermal effect was applied to a three-floor solar chimney, the heating energy use increased to about 7.6 times higher than that of the original performance of the double-skin facade.

ТЕМПЕРАТУРНІ ЗМІНИ СХІДНО-УКРАЇНСЬКОГО РЕГІОНУ ТА ЇХ ВПЛИВ НА РОБОТУ ТРАНСПОРТУ

The article explores the issues of temperature changes in the environment in winter and their impact on the operation of transport. The degree of influence of temperature on the mode and safety of transport depends on the intensity of meteorological changes, therefore, the study of fluctuations in meteorological changes in temperature is important for a comprehensive understanding of causal relationships between factors affecting the operation of vehicles. For the study, the East Ukrainian region was selected, with its temperature characteristics. One of the features of this region is that a change in temperature conditions is influenced by the nearby Azov Sea. The influence of climatic conditions on the performance of vehicles is determined, first of all, by the fact that under the influence of low temperatures, the modes of motion change, as well as the physical and mechanical properties of structural materials. The study was conducted on the basis of ten-day temperatures in Mariupol from 2014-2018 using trend modeling. We used the basic principles of the inversion of temperature changes and automobile theory to formulate and solve the research problem. The dependences of the maximum and minimum temperatures on time are established, changes in the average ten-day air temperature that affect the design of moving vehicles, their paths and performance are analyzed. An increase in the average annual temperature was revealed, which can cause the accumulation of greenhouse gases and lead to climate disturbances. The study indicates a gradual warming of the climate, which in turn can lead to a change in the performance of transport in the East Ukrainian industrial-agricultural region. Ways to solve the environmental problem are proposed, including reducing carbon dioxide emissions and creating an environmentally sustainable transport system, as well as ways to reduce theenvironmental impact of transport, including the use of alternative fuels, commissioning electric vehicles and creating traffic structures.

The Changing Distribution of Anthocyanin in Mikania micrantha Leaves as an Adaption to Low-Temperature Environments.

Anthocyanins, a protective substance in plant leaves, can accumulate in large quantities under low-temperature induction. In order to explore the effect of anthocyanins in Mikania micrantha leaves, the Rubisco, photosynthesis, pigments, and antioxidative capacity in mature leaves (ML) and young leaves (YL) of M. micrantha were investigated in winter. YL were red on both the adaxial and abaxial surfaces, while ML was red on the abaxial surfaces and green on the adaxial surfaces. Compared with ML, the relative expression of the genes related to anthocyanin synthesis and anthocyanin content were significantly higher in YL. Antioxidants such as flavonoids and total phenols were found in higher quantities, and the total antioxidant capacity was also significantly higher in YL. However, in ML, the Rubisco and chlorophyll content related to photosynthesis were significantly higher. The stomata of ML displayed a larger aperture than YL, and the stomatal conductance and photosynthetic rate were significantly higher in ML. The results suggested that M. micrantha leaves could better adapt to the winter environment through changing the distribution of anthocyanins in leaves of different maturity.

‘Winter children’: an ethnographically inspired study of children being-and-becoming well-versed in snow and ice

ABSTRACT For many children living in Northern and mountainous regions of the world, playing in snow is enticing and connotes childhood for many adults. Even so, researchers have paid little attention to children’s play in/with snow and ice. This paper aims to contribute to the growing knowledge on children’s competencies and child-nature relationships by exploring how a group of children build their understanding of themselves and their environment during playful explorations in demanding winter landscapes. The study is framed by (1) a phenomenological-hermeneutic approach, (2) an analysis of selected evocative empirical examples of ways children play in/with winter materials, and (3) perspectives on ‘Bildung’ as dialectical processes of being-and-becoming. Data were generated through ethnographically inspired fieldwork, including 20 children aged four to six, in a Norwegian Nature Kindergarten, emphasizing children’s self-initiated outdoor play as educationally important. The fieldwork was conducted in 2018 during the coldest time of the year and draws on participant observation, children’s photographs and on-site conversations. The study is inspired by the work of [Ingold, T. (2011). Being alive. Oxon: Routledge], [Merleau-Ponty, M. (2012). Phenomenology of perception. London: Routledge], [Gibson, J. J. (1979). The ecological approach to visual perception. NJ: Lawrence Erlbaum Associates], and the Continental European philosophy of Bildung [Biesta, G. (2002). Bildung and modernity: The future of Bildung in a world of difference. Studies in Philosophy and Education, 21(4–5), 343–351] and applies Ingold’s concepts of ‘lines’, ‘knots’ and ‘dwelling’, to explore children’s playful movements and experiences along lines in an ever-evolving meshwork. Three themes are analyzed. First, the ever-transforming qualities of snow and ice are discussed as existential materials and cultural conditions in the children’s dialectical process of being-and-becoming. Second, the kindergarten’s snow-covered playground is seen as attractive and challenging from the children’s perspective. Third, as the children increase their competence in the dynamic winter environment through movement, they embody existential knowledge and skills about the socio-material context of which they are a part. Thus, they familiarize themselves with their environment as being-and-becoming winter children.

Response of growth, yield, and quality of edible-podded snow peas to supplemental LED lighting during winter greenhouse production

The occurrence of low natural light levels during winter months is a major limiting factor for greenhouse plant production in northern regions. To determine the effects of supplemental lighting (SL) on winter greenhouse production of pea pods, plant growth, pod yield, and quality were investigated under SL at a photosynthetic photon flux density (PPFD) of 50, 80, 110, and 140 μmol m−2 s−1, plus a no-SL control treatment, inside a Canadian greenhouse from January to March. Light-emitting diodes with a red-to-blue PPFD ratio of 4:1 and a 16 h photoperiod were used for the lighting treatments. During the trial period, the average natural daily light integral (DLI) inside the greenhouse was 6.6 mol m−2 d−1 and the average daily temperature was around 13 °C. Compared with the control, SL treatments increased pod yield and promoted plant growth, as demonstrated by faster main stem extension and greater aerial biomass. Also, total pod yield (g plant−1 or no. plant−1) and some growth traits (e.g., stem diameter, branch number, leaf thickness, and leaf chlorophyll content) were proportional to supplemental PPFD within the range of 0–140 μmol m−2 s−1. However, SL levels of 50–80 μmol m−2 s−1, corresponding to a total (natural + supplemental) DLI of 9.4–11.1 mol m−2 d−1, resulted in the best pod quality based on evaluations of individual fresh mass, length, soluble solids content, succulence, and firmness. Therefore, a total DLI ranging between 9.4 and 11.1 mol m−2 d−1 can be recommended as a target light level for greenhouse production of pea pods using SL under winter environment conditions.

Integration of QTL Mapping and Gene Fishing Techniques to Dissect the Multi-Main Stem Trait in Rapeseed (Brassica napus L.).

Rapeseed is one of the most important oilseed crops in the world. Improving the production of rapeseed is beneficial to relieve the shortage of edible vegetable oil. As the organ of support and transport, the main stem of rapeseed controls the plant architecture, transports the water and nutrients, and determines the number of inflorescence. Increasing the number of main stems would be helpful for the yield improvement in Brassica napus (B. napus). This attractive multi-main stem (MMS) trait was observed in the KN DH population. We investigated not only the frequency of MMS traits but also dissected the genetic basis with QTL mapping analysis and Gene-Fishing technique. A total of 43 QTLs were identified for MMS based on high-density linkage map, which explained 2.95–14.9% of the phenotypic variation, among which two environmental stable QTLs (cqMMS.A3-2 and cqMMS.C3-5) were identified in winter and semi-winter environments. Epistatic interaction analysis indicated cqMMS.C3-5 was an important loci for MMS. According to the functional annotation, 159 candidate genes within QTL confidence intervals, corresponding to 148 Arabidopsis thaliana (A. thaliana) homologous genes, were identified, which regulated lateral bud development and tiller of stem, such as shoot meristemless (STM), WUSCHEL-regulated-related genes, cytokinin response factors (CRF5), cytokinin oxidase (CKX4), gibberellin-regulated (RDK1), auxin-regulated gene (ARL, IAR4), and auxin-mediated signaling gene (STV1). Based on Gene-Fishing analysis between the natural plants and the double-main stem (DMS) plant, 31 differentially expressed genes (DEGs) were also obtained, which were related to differentiation and formation of lateral buds, biotic stimulus, defense response, drought and salt-stress responses, as well as cold-response functional genes. In addition, by combining the candidate genes in QTL regions with the DEGs that were obtained by Gene-Fishing technique, six common candidate genes (RPT2A, HLR, CRK, LRR-RLK, AGL79, and TCTP) were identified, which might probably be related to the formation of MMS phenotype. The present results not only would give a new insight into the genetic basis underlying the regulation of MMS but also would provide clues for plant architecture breeding in rapeseed.

Winter indoor environment of elderly households: A case of rural regions in northeast and southeast China

To study the winter indoor environment in the rural homes with elderly individuals in different climate regions, households with elderly individuals in Qiqihar (northeast China) and Shanghai (southeast China), were selected for questionnaire surveys (50 and 60 households in Qiqihar and Shanghai, respectively) and field measurements (10 and 5 households in Qiqihar and Shanghai, respectively). The field measurements included the monitoring of air temperature, relative humidity (RH), carbon dioxide (CO2), particulate matter (PM) with an aerodynamic diameter of 2.5 μm or less (PM2.5), carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOCs), and semi-volatile organic compounds (SVOCs) concentration. The results indicated that elderly individuals in Qiqihar had large temperature steps ranging from 15 to 35 °C between the indoor and outdoor, and experienced unsteady thermal environment, but those in Shanghai experienced low temperature, high RH, and steadier thermal environment. Additionally, the thermal neutral temperatures in Qiqihar and Shanghai were 17.32 °C and 16.91 °C, higher than air temperatures for living-bedrooms/kitchens (14.5 ± 4.3 °C/12.8 ± 4.7 °C) and for living rooms/bedrooms (10.4 ± 1.5 °C/10.5 ± 1.5 °C). Moreover, the older people had higher blood pressure in lower temperature. Qiqihar households showed more serious air pollution than Shanghai. For Qiqihar households, the concentration of PM2.5 and total VOCs (TVOC), which exceeded the standard, accounted for 90%, while PM2.5 concentrations in 4 households were 6 times higher than the standard. This study provides valuable data for future work on environmental risk assessment in elderly households in rural areas.

The research on the influence of building air tightness to energy consumption of residential building in a hot summer and cold winter zone in China

The hot summer and cold winter zone in China belong to the non-central heating area. In recent years, with the improvement of people’s living standards, more and more residential building have begun to adopt various heating methods. However, many existing buildings have poor air tightness level, and the indoor thermal environment is in a bad condition, which also causes a great waste of energy. Based on the actual measurement of the airtightness of a demonstration building, this paper studies the effects of residential airtightness on heating and air conditioning energy consumption and indoor thermal environment in winter. The simulation results show that in the hot summer and cold winter zone, the level of air tightness also influence the heating and air conditioning energy consumption, but the impact on heating energy consumption is more obvious. In addition, when selecting energy-saving measures, the relationship between the level of air tightness and the level of insulation should be weighed. We should not reduce energy consumption only by improving the airtightness level. Otherwise, the investment is large and the energy saving effect is very poor.

Performance evaluation and comparison between rural new and traditional house in severe cold regions of China

With the development of urban-rural integration, the number of newly built houses is increasing. Due to the influence of climatic characteristics, traditional technology, economy etc, the phenomenon of large heating energy consumption and low indoor thermal comfort in winter is common in rural houses. In order to explore the energy-saving design methods for rural houses in severe cold regions and create a low-carbon and comfortable indoor thermal environment in winter, this paper selects the new house and traditional house of Zhalantun, Inner Mongolia as research objects, applying the methods of testing and calculation to comprehensive comparison of the differences between two types of housing from the aspects of building energy consumption, indoor thermal environment and thermal performance of building envelop. Results show that through the reasonable thermal environment zoning, performance optimization of building envelop and improvement of heating mode etc., the indoor thermal environment can be effectively improved, so as to achieve the purpose of comfort and energy saving.

Using fertiliser to maintain soil inorganic nitrogen can increase dryland wheat yield with little environmental cost

Nitrogen (N) deficiency is responsible for a large proportion of the exploitable yield gap that exists in Australian wheat production. In order to maximise N use efficiency (NUE), growers attempt to match N fertiliser to seasonal water limited yield potential, which in the southern grain growing region is largely determined by in-crop rainfall. Australia’s variable rainfall makes water limited yield potential very difficult to predict, and growers tend to under fertilise, fearing economic and environmental losses of N if crops are over-fertilised. However, environmental losses of excess N are low in the semi-arid, winter dominant rainfall environments with high water holding capacity soils that comprise much of the wheat producing regions of south eastern Australia. This is particularly the case when high carbon (C) to N ratio crop residues are retained which facilitate rapid immobilisation of any mineral N surplus to crop requirements. We therefore propose that the exploitable yield gap in wheat could be closed if a longer-term strategy of N fertiliser application was adopted. In this strategy, growers would simply use N fertiliser to maintain an environmentally appropriate base level of inorganic N (N bank) rather than attempting to match fertiliser inputs to seasonal conditions. We used field studies with 15N labelled fertiliser and cropping systems simulations to demonstrate that fertiliser N applied at rates calculated to maintain fixed thresholds of inorganic N (N bank criteria) and top-dressed immediately prior to the period of rapid crop uptake can substantially increase yields and profit in comparison to current practice, even when applications exceed crop demand in some years. A further benefit of this strategy is an increase in soil organic matter. Both field and simulation studies indicate that the environmental cost of such a strategy would be minimal, with only a small increase in leaching and denitrification despite higher overall rates of N application. This strategy needs to be compared with current practices in longer term field experiments to confirm production increases and lack of environmental impacts.

Investigation and low energy improvement of the thermal environment of work areas in the Qingdao Metro in winter

Few studies have investigated the thermal environment of the work area hall in underground metro stations during winter. Two underground stations were chosen within Qingdao Metro Lines 2 and 3 to investigate the thermal environment in the work area hall in northern city metros in China. Air temperatures and wind velocity parameters were identified as key influencing factors and were continuously measured in the work area. The study found that the thermal environment fluctuates frequently in the work area throughout the day. Changes in temperatures and wind speeds were periodically caused by piston wind flowing from the platform level. To improve this heating situation in the work area in winter, the study proposes recycling waste heat from the power equipment rooms, using the air source but through the water cycle heat pump system. Insights from the study may help save energy and improve the thermal environment, and could be applied across metro stations in north China cities in winter. Practical application: The thermal comfort of the working area in the metro station hall is extremely poor as indicated by a study of Qingdao Metro stations. This paper explores the application of a heat pump as a means of heating the working area to improve the cold and damp winter environment for the metro staff using waste heat from the machine rooms.

Evaluation of patients’ real-world post-dispensing use and storage environments of tiotropium bromide Respimat® soft mist inhaler on its in vitro dose delivery and lung deposition

BackgroundOral inhalation is the main drug delivery route for treating obstructive lung conditions. Thus, many inhaler devices with various design and pharmaceutical formulation have been introduced. The fine particle dose (FPD) and mass median aerodynamic diameter (MMAD ≤ 5 μm) of the aerosol delivered dose (DD) dictate the therapeutically effective peripheral lung deposition. This study evaluated the in vitro aerosol emission performance of tiotropium bromide emitted from Spiriva® Respimat® soft mist inhalers (R) after living under patients’ real-world, post-dispensing handling environments. MethodsThis was a two-stage investigation. In the first clinical stage, research ethical approval was obtained to enrol patients already been using R for at least 3 months. Those who signed consent were given both new R to use and temperature and relative humidity (RH) handheld, portable data loggers to keep in the vicinity of the given R. The participants returned the given R and data loggers after 2 weeks. Patient recruitment took place in Amman, Jordan, during the summer (RS) and winter (RW). Subsequently, in the second laboratory stage, other R were strictly stored at an average of 21.0 °C and 46.9% RH as control (RC). The Next Generation Impactor (NGI) was used to evaluate the RS, RW and RC. The NGI was operated at a flow rate of 30 L/min. ResultsThe RS were exposed to an average (range) 23.6 °C (18.2–37.5 °C) and 43.8% RH (21.4–60.0% RH) that were statistically comparable (p > 0.05) to that of the RW; 17.3 °C (13.2–26.7 °C) and 52.8% RH (26.3–69.1% RH). The RW and RC retention environments were statistically different (p < 0.05), whilst the RS and RC had comparable (p > 0.05) conditions. No significant differences (p > 0.05) were found in the tiotropium bromide DD (2.39 vs 2.43 μg), FPD (0.88 vs 0.90 μg) and MMAD (5.1 vs 4.98 μm) between the RS and RW, respectively. Compared to the RC inhalers, both the RS and RW devices had significantly higher FPD and relatively smaller tiotropium bromide particles. ConclusionsUsing the R under the fluctuating summer and winter environments of our patients would not affect its overall tiotropium bromide emission performance. The significant increase in the respirable mass of the RS and RW might be offset by the increase in particles <1 μm particularly in patients with poor inhaler technique.

Study on winter indoor thermal environment of temporary shelters built in Nepal after massive earthquake 2015

After massive earthquake 2015, thousands of Nepalese who lost their permanent houses by the hardest hits were forced to live in makeshift temporary shelters. The people residing in these shelters are facing extreme coldness that causes various health-related problems in winter. The field measurement on indoor thermal environment was conducted in one of the district hit by massive earthquake, Lalitpur. The indoor and outdoor air temperatures of five shelters were measured by a set of thermometers with digital data loggers at the ten minute intervals in winter. The mean indoor and mean outdoor air temperatures during the measured night-time were found to be from 10.3°C and 7.6°C; they were lower than lower limit value of acceptable indoor temperature at 11°C found from our previous research. We analyzed the thermal characteristics of those shelters measured for seeking whether the improvement is possible or not and also how much of it is affordable. Thus, in this study, we evaluated the indoor thermal environment by estimating the heat-transmission characteristics of the used materials in these investigated shelters. The total heat loss coefficient estimated in five shelters per respective floor areas ranged from 11.2 to 15.4 W/(m2·K). These values obtained are very large due to low thermal insulation materials used. The paper ends with important lesson that reduce the total heat loss coefficient needs to reduce down to 2∼7 W/(m2·K) for realising the need to indoor air temperature above at 11°C could be 70% of nighttime hours. Such reduction of heat loss was found to be realized by adding affordable materials, i.e. cellular polyethylene foam and clothes for respective walls and roof.

Thermal behaviour of a green roof containing insulation cork board. An experimental characterization using a bioclimatic chamber

Green roof technology is increasingly being used to improve the energy and environmental performance of buildings. However, the description of the thermal behaviour of green roofs is very complex since it depends on several variables and relies on intricate phenomena.In this work the authors characterize a green roof system that replaces the conventional drainage and water storage polyethylene membranes with insulation cork boards (ICB). To enable the experimental characterization of this system, a double walk-in bioclimatic chamber was designed and built to recreate indoor and outdoor environmental conditions. Winter and summer environments with steady and unsteady conditions in both dry and wet states were simulated. Thermocouples and heat flux sensors were used to collect data over time from the different layers of the green roof prototypes.Measurements were first performed on a concrete slab insulated with ICB to assess the contribution of the latter to the thermal performance of the system. The effect on the heat transfer was further evaluated for systems of increasing complexity, containing first a substrate layer and then vegetation. It was noted that the substrate and vegetation layers improved the thermal insulation, and reduced heat fluxes and the thermal amplitude within the system. The vegetation layer was found to be of key importance to the overall performance of the green roof. It was also found that ICB and the substrate layers lose part of their insulation capacity when the system was wetted, although it was fully restored in the ICB layer within a few hours.

The comparative study on the climate adaptability based on indoor physical environment of traditional dwelling in Qinba mountainous areas, China

The acceleration of urbanization and the growth of population are considered to be the reasons of increasing demands for construction, life quality and energy consumption. This leads to more research in climate adaptive strategies such as traditional design methods, construction techniques and building materials. Traditional dwelling has been successful in achieving harmony between dwelling and climatic environment, which is one of the most important conditions for sustainability. Firstly, this paper focused on analyzing the characteristics of traditional dwellings in Qinba mountainous areas to adapt to the climatic environment. Secondly, two typical dwellings constructed respectively with brick and earth materials were selected for monitoring and simulating of its indoor thermal, luminous and ventilation environment in summer and winter. In addition, the research summarized the advantages and disadvantages of the dwelling's physical environment in response to climatic characteristics. It revealed that the traditional earth dwelling is well adapted to the local climate during summer, although the indoor thermal comfort is not fully satisfactory during winter. Finally, we prompted effective climate adaptive strategies of traditional earth dwelling, such as natural ventilation, thermal insulation and thermal buffer space. We want to provide guidance and reference for the development of traditional dwellings in the mountainous areas.

Mooring system reliability in tropical cyclone and North Sea winter storm environments

The characteristics of waves, winds and currents in a tropical cyclone environment differ significantly from those in a winter storm environment, like the North Sea. This can have a significant effect on the reliability of a mooring system that is designed to satisfy 100 yr conditions with specified Factors of Safety in accordance with ISO19901-7 or API RP 2SK. This paper presents reliability analysis of the mooring system of a permanently connected Floating LNG vessel, placed at two locations: (a) a tropical cyclone environment of the North West Shelf of Australia and (b) a winter storm environment of the North Sea. It is demonstrated that as a result of differences in the long term distribution of environmental parameters (waves, winds) between a North Sea environment and a tropical cyclone environment, the long term distribution of the mooring line response differs significantly in these two locations.This paper shows that a mooring system which is designed in accordance with ISO (or API), in these two environments, will achieve very different reliability levels because of the significant differences in environmental characteristics. In order to achieve the same reliability for the mooring system at these two geographical locations, Factors of Safety for use with 100 yr environmental conditions (Ultimate Limit State) were derived to achieve the same target probability of failure of 10−4/annum. It was found that for the North Sea environment, a factor of 1.5 is required for both the mooring chain and the pile, while for the tropical cyclone environment the required Factor of Safety has to be increased to 2.1. These differences are very significant and design standards need to be revised to reflect these findings.

Evaluation of thermal comfort in a historic building refurbished to an office building with modernized HVAC systems

ABSTRACTEnvelopes with low thermal performance are common characteristics in European historic buildings, causing higher energy demand and insufficient thermal comfort. This paper presents the results of a study on indoor environmental quality (IEQ), with special focus on thermal comfort, in the historic City Hall of Gävle, Sweden, now used as an office building. There are two modern heat recovery ventilation systems with displacement ventilation supply devices. The district heating network heats the building via pre-heat supply air and radiators. Summer cooling comes from electric heat pump ejecting heat into the exhaust ventilation air. A building management system (BMS) controls the heating, ventilation and air-conditioning (HVAC) equipment. The methodology included on-site measurements, BMS data logging and evaluating the occupants’ perception of a summer and a winter period indoor environment using a standardized questionnaire. In conclusion, indoor environmental quality in this historic building is unsatisfactory. Stuffy air, too high, too low and varying room temperatures, lighting problems and noise are constant issues. Although it is equipped with modern ventilation systems, there are still possibilities for improving thermal comfort by improved control strategies, since upgrading the building’s envelope is not allowed according to the Swedish Building Regulations in historic buildings with heritage value.

Outbreak of a new alien invasive plant Salvia reflexa in north‐east China

SummaryThe establishment of invasive species is widely recognised as a pivotal issue in the preservation of biodiversity. Salvia reflexa, a species native to the south‐central United States and Mexico, has been widely introduced in Argentina, Australia, New Zealand and Japan. In China, the first population of this plant was found growing adjacent to a grain depot in Shahai village, Jianping County, Liaoning Province, on 25 July 2007. Since the grain depot imported foodstuffs from regions where the plant is native, we infer that S. reflexa was introduced into China via imported foodstuff in the early to mid‐2000s. Based on field observations, at least seven populations of this plant were observed in north‐east China. The plants displayed vigorous growth in midsummer and produced prolific seeds to overcome the cold environment in winter. Salvia reflexa occurred in both dense monocultures and in mixed stands with native plants. In order to validate a system for recognising and categorising non‐native plants in China, the Australian Weed Risk Assessment system was used to assess the invasiveness status of 19 exotic and 16 native plants in north‐east China. Salvia reflexa exhibited a high score of 10, suggesting it is a potentially pernicious alien invasive plant. Although the current distribution of S. reflexa is restricted to Liaoning province and thus far has limited impact on local environments, local regulatory authorities should pay close attention to this plant and take measures to stop its expansion. This is the first time that an invasive plant from the Lamiaceae (mint family) has been documented from cold environments in China.

Study on indoor thermal environment of rural dwellings in Northwest China in winter

In order to study the status of the indoor thermal environment of the northwest rural dwellings in winter, the thermal performance and the residents’ adaptability are investigated and the indoor and outdoor thermal environment parameters are measured in Zhongwei region of Ningxia, the indoor thermal environment is analyzed and evaluated by the operating temperature. The results show that the northwest rural residents have strong adaptability to the cold indoor thermal environment in winter. In this area, the cold and daily temperature difference in winter is large, but the solar energy is rich, and it has the geographical advantage of developing passive solar building. The thermal performance of existing rural dwellings is poor and the indoor thermal environment is not ideal. It is necessary to enhance the thermal performance of building’s heat collection, thermal storage and enclosure structure.