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In this paper, a simple model is proposed for predicting the thermal energy requirements of greenhouses in Europe. The model estimates the annual heating requirements and the maximum required heating power, along with the corresponding heating and zero-energy operating periods. It is based on the greenhouse technical data (the overall heat loss coefficient, cover transmission, sensible absorbance), the cultivation conditions (temperature range), and the meteorological data (solar radiation and ambient temperature) according to the site characteristics (longitude and latitude). The model results can be obtained using a hand calculator. The model results are compared with those of a detailed model simulating a greenhouse's thermal performance and they agreed with real data from the literature. Moreover, a model sensitivity analysis revealed the effect of various factors on the greenhouse's energy requirements. The results proved that the most significant factor affecting heating requirements, the maximum heating power, and heating periods is the latitude of the greenhouse site, whereas zero-energy periods are primarily influenced by the plant cultivation temperature range and then by the latitude. According to our findings, in lower latitudes (40 to 50 degrees), heating requirements range from 250 to 430 kWh/m2/y, whereas, in higher latitudes (50 to 60 degrees), heating needs range from 430 to 650 kWh/m2/y. [ABSTRACT FROM AUTHOR]

The effects of chemical components of ambient fine particulate matter (PM 2.5) on human early maternal−fetal interface are unknown. We estimated the associations of PM 2.5 and component exposures with placental villi 8-hydroxy-2′-deoxyguanosine (8-OHdG) in 142 normal early pregnancy (NEP) and 142 early pregnancy loss (EPL) from December 2017 to December 2022. We used datasets accessed from the Tracking Air Pollution in China platform to estimate maternal daily PM 2.5 and component exposures. Effect of average PM 2.5 and component exposures during the post-conception period (i.e., from ovulation to villi collection) on the concentration of villi 8-OHdG were analyzed using multivariable linear regression models. Distributed lag and cumulative effects of PM 2.5 and component exposures during the periovulatory period and within ten days before villi collection on villi 8-OHdG were analyzed using distributed lag non-linear models combined with multivariable linear regression models. Per interquartile range increase in average PM 2.5 , black carbon (BC), and organic matter (OM) exposures during the post-conception period increased villi 8-OHdG in all subjects (β = 34.48% [95% CI : 9.33%, 65.42%], β = 35.73% [95% CI : 9.08%, 68.89%], and β = 54.71% [95% CI : 21.56%, 96.91%], respectively), and in EPL (β = 63.37% [95% CI : 16.00%, 130.10%], β = 47.43% [95% CI : 4.30%, 108.39%], and β = 72.32% [95% CI : 18.20%, 151.21%], respectively), but not in NEP. Specific weekly lag effects of PM 2.5 , BC, and OM exposures during the periovulatory period increased villi 8-OHdG in all subjects. Ten−day cumulative and lag effects of PM 2.5 , BC, and OM increased villi 8-OHdG in all subjects and EPL, but not in NEP; and the effects of OM were robust after adjusting for BC, ammonium, nitrate, or sulfate in two-pollutant models. In conclusion, placental oxidative DNA damage in early pregnancy was associated with maternal exposure to PM 2.5 , especially its chemical components BC and OM. [Display omitted] • The first study on effects of PM 2.5 chemical components on the human early placenta. • Periovulatory and post-conception PM 2.5 , BC, and OM exposures increased villi 8-OHdG. • PM 2.5 , BC, and OM induced placental DNA damage in early pregnancy especially in EPL. • OM was the component with the strongest effects in this study, followed by BC. • PM 2.5 , BC, and OM increased villi 8-OHdG all year especially during heating period. [ABSTRACT FROM AUTHOR]

The damage to the environment caused by fossil-derived fuels is very high. Each year air pollution causes the death of close to 3 million people. This value is equivalent to 5% of the global annual death rate. In the literature, greenhouse gas emission calculations are made with data officially recorded from annual fuel and electricity consumption in housing on a provincial basis. These calculations do not differentiate energy consumed for heating, hot water or domestic appliances (fridge, air conditioning, washing machines, dishwashers, iron, oven, etc.). This study calculated energy requirements for heating and per person emissions with a new method taking account of different wall types, fuel and insulation material for İzmir province. The carbon dioxide amount released per unit area in the heating period (CDUAHP) and sulfur dioxide released per unit area in the heating period (SDUAHP) were compared according to wall, fuel and insulation material types and without insulation. The effect of optimum insulation thickness (OIT) on the environment and energy was calculated for İzmir. It was determined that with different fuel, isolation material and wall types, energy demand and CDUAHP reductions could reach 76% levels. Two new approaches of carbon dioxide amount per person in the heating period (CDPPHP) and sulfur dioxide amount per person in the heating period (SDPPHP) were developed. For 1TEIW with XPS according to OIT and coal as fuel, the CDPPHP was 836 kg/person year, while the SDPPHP for an uninsulated apartment was 7196 kg/person heating period, with 1727 kg person/heating period calculated according to OIT. [ABSTRACT FROM AUTHOR]

Nitrous acid (HONO) is of great interest due to its contribution to hydroxyl (OH) radicals by self-photolysis. Nowadays, machine learning (ML) algorithms are good at capturing complicated non-linear relationships between predictors and dependent variables. Here, using the whole year of 2018 of observed HONO and related pollutant data at an urban site in Beijing, an ML-RF (random forest) model is carried out to predict HONO concentrations and explore the main factors influencing HONO formation mechanisms. ML-RF models show satisfactory performance during the heating, non-heating and whole year periods with R values of 0.95, 0.96 and 0.95, respectively. Primary emissions and diffusion have an obvious influence on ambient HONO during the heating period, while chemical formation processes such as NO 2 heterogeneous reaction and photolysis of nitrate are important for HONO during the non-heating period with higher RH and stronger solar intensity. O 3 and NH 3 are the most important variables for HONO in both periods, indicating the close relationship of HONO with atmospheric oxidation and the important role of NH 3 in HONO formation processes. Although there are deviations due to some variability in HONO formation mechanisms between years, ML-RF models based on 2018 data are able to roughly predict HONO for three periods in 2017 and 2021. Overall, machine learning with limited meteorological and pollutant parameters offers great advantages in HONO prediction, and it can also provide some clues to improve the chemical mechanisms of HONO by finding related variables of ambient HONO. [Display omitted] • Machine learning predicted HONO shows satisfactory performance in 2018. • O 3 and NH 3 are the most important HONO predictors. • Main HONO sources are different between heating and non-heating periods. • Machine learning model is feasible to predict HONO across years. [ABSTRACT FROM AUTHOR]

The distribution characteristics and sources of gaseous elemental mercury (GEM) on haze and non-haze days are still not clear. During the winter heating period in 2017, the GEM concentrations in Qingdao were studied for their differences, sources, and pollution characteristics on haze and non-haze days. The GEM concentration on haze days (2.81 ± 2.23 ng/m3) was higher than that on non-haze days (1.90 ± 1.21 ng/m3) and the difference was significant (p < 0.01) during the period of artificial heating. The average concentration of GEM was 2.27 ng/m3 in the heating period, but lower than that before heating (3.30 ng/m3). However, the mercury to carbon monoxide ratio (GEM/CO) on haze days was lower than that on non-haze days. The ratio of GEM/CO in this study was lower than that in other studies reported from China. There was a positive correlation between the GEM/CO ratio and the air temperature (p < 0.01), suggesting that the mercury released from the Earth's surface was important. The environmental policies of China also contributed to decrease of the GEM/CO ratio. Similar diurnal patterns appeared on both haze and non-haze days, with one GEM peak at 14:00–15:00. This pattern was different from the bimodal pattern of other atmospheric pollutants in the morning and evening rush hours and was controlled by GEM from the Earth's surface (mostly re-emission of legacy Hg) whether on haze or non-haze days. Principal component analysis showed that the contribution of GEM directly from anthropogenic sources was relatively small. The main influencing factor on haze days was air temperature. GEM concentrations showed large spatial differences in air masses from different places. The GEM concentration in air masses from southern and the western Shandong Province was higher than from the north on haze days. Unlabelled Image • GEM concentration on haze days was higher than that on non-haze days. • GEM/CO ratio on haze days was lower than that on non-haze days. • GEM diurnal variation on haze days was controlled by solar radiation. • Air masses from the south had higher GEM and GEM/CO ratio than that from the north. [ABSTRACT FROM AUTHOR]

Since the implementation of the Action Plan for Air Pollution Prevention and Control, all regions of China have steadily promoted the prevention and control of air pollution and achieved results continuously. However, the atmospheric environment in key areas such as Beijing - Tianjin - Hebei region, the Yangtze River Delta region, and Fenwei Plain is still severe, and especially during the heating period heavy pollution occurs frequently, which has become the focus and difficulty of improving the quality of the atmospheric environment and is also the weakest link of China's air pollution control at present. How to alleviate air pollution, how to win the battle of pollution prevention and control, how to hold the fruits of the blue sky defense war, energy consumption is key. [ABSTRACT FROM AUTHOR]

China's aging population is growing rapidly. To date, there have been few literatures concerning indoor environment of private houses with older people. This study fully investigated indoor environment in 10 houses (5 urban and 5 rural houses) with older people during heating season in Beijing, China. Each house was assessed for temperature, relative humidity, CO 2 , PM 2.5 , CO, NO x , formaldehydes, acetaldehyde, VOCs, SVOCs and fungi. Results indicated older people in urban houses experienced a steadier and warmer thermal environment than those in rural houses, due to the difference of heating devices between urban and rural houses. Indoor CO 2 levels mainly increased up to 1000 ppm in the bedroom during sleeping time. For rural houses, indoor fuel combustion contributed to an extremely high PM 2.5 and CO level. Formaldehyde, acetaldehyde, toluene, ethylbenzene and xylenes levels in most houses were lower than the limit values. However, the integrated influence of these compounds was unnegligible. TVOC concentrations in four measured houses exceeded the reference value of 600 µg/m 3 . The most frequent fungi was Cladosporium spp. (90%), followed by Penicillium spp . (70%) and Aspergillus spp. (60%). The fungal levels in rural houses were higher than urban houses. These results will be beneficial to improve housing environmental quality for older people in China. [ABSTRACT FROM AUTHOR]

ABSTRACT As the coolest region in China, Northeast China has long and severe winters and is a main region for the use of central heating. Accurately predicting the heating energy consumption in Northeast China is very important for energy management and planning. Based on daily mean temperature data from 70 weather stations, this study investigated the spatiotemporal changes in the starting date for heating ( HS), the end date for heating ( HE), and the length ( HL) and the heating degree days ( HDD) of the heating period in Northeast China. Over Northeast China, regional averaged HS has become later by 0.77 days decade−1 and HE has become earlier by 1.19 days decade−1 during 1960-2011. Accordingly, regional averaged HL and HDD decreased significantly by 1.97 days decade−1 and 66.28 °C decade−1 respectively; this implies a decreasing demand for heating throughout the region. Spatially, the temporal trends of each heating variable varied in different locations. The spatial patterning of the HL trend was unlike that of the HDD trend due to different responses of HL and HDD to climate change. Temperature increase seems to have larger impacts on HL in warm south localities but more obvious effects on HDD in cold north localities of Northeast China. These different sensitivities of HL and HDD to temperature change should be considered when attempts are made to predict heating energy consumption in Northeast China in a changing climate. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) and its oxygenated derivatives (OPAHs) are toxins in PM 2.5 . Little information has been known for their transformation in the ambient airs. In this study, PM 2.5 samples were collected at 19 sampling sites in Xi’an, China during the heating period, which is classified into: urban residential, university, commercial area, suburban region, and industry. Organic compounds including PAHs, OPAHs, hopanes and cholestanes were quantified. The average of total quantified PAHs and OPAHs concentrations were 196.5 ng/m 3 and 29.4 ng/m 3 , respectively, which were consistent with other northern cities in China. Statistical analyses showed that there were significant differences on the distributions of PAHs between urban and suburban regions. The industry also had distinguishable profiles compared with urban residential and commercial area for OPAHs. The greater diversity of OPAHs than PAHs might be due to different primary emission sources and transformation and degradation pathways. The ratios of OPAHs to the corresponding parent PAHs, including 9-fluorenone/fluorene, anthraquinone/anthracene, benz[ a ]anthracene-7,12-dione/benzo[ a ]anthracene were 6.2, 12.7, and 1.4, respectively, which were much higher than those for the fresh emissions from coal combustion and biomass burning. These prove the importance of secondary formation and transformation of OPAHs in the ambient airs. Biomarkers such as retene, cyclopenta[CD]pyrene and αα-homohopane were characterized for the source apportionment. With Positive Matrix Factorization (PMF) model analysis, biomass burning was recognized as the most dominant pollution sources for PAHs during the heading period, which accounted for a contribution of 37.1%. Vehicle emission (22.8%) and coal combustion (22.6%) were also contributors in Xi’an. [ABSTRACT FROM AUTHOR]

The diurnal variations of the water soluble organic and inorganic components as well as six selected metals in PM 2.5 around the heating periods of 2013 and 2014 in Beijing were analyzed in this study to investigate the contributions of secondary aerosols and primary pollutants to PM 2.5 and the effects of domestic heating and mitigation measures. The before-heating sampling period in 2014 (from Nov. 1st to Nov. 15th) was characterized with reinforced short-term mitigation measures for the 2014 Asia–Pacific Economic Cooperation (APEC) meeting. As a result, the average mass concentrations of PM 2.5 and most of the measured species except for Cu, Al, and Ca 2+ were greatly reduced during the APEC meeting period. The domestic heating activity alone resulted in a 17.7% increase of PM 2.5 in 2013, exerting lesser effects on the increase of PM 2.5 than before. Water soluble organic carbon was the most abundant water soluble species in PM 2.5 , followed by NO 3 − , SO 4 2 − , and NH 4 + . According to the PMF model calculation, secondary aerosols, coal combustion, biomass/waste burning, traffic related pollution, long-range transport, and fugitive soil and sand dust were identified as the main sources of PM 2.5 in Beijing, among which secondary formation of aerosols was the dominant source of PM 2.5 during the non-APEC period while biomass/waste burning dominated during the APEC period. As a timely feedback on the effects of the mitigation measures adopted by the government, the results of this study provide knowledge necessary for a sustainable urban management. [ABSTRACT FROM AUTHOR]

By this study, it was aimed to define a testing and calculation model for thermal comfort assessment of a bus HVAC design and to compare effects of changing parameters on passenger's thermal comfort. For this purpose, a combined theoretical and experimental work during heating period inside a coach was carried out. The bus was left under 20 °C for more than 7 h within a climatic chamber and all heat sources were started at the beginning of a standard test. To investigate effects of fast transient conditions on passengers' physiology and thermal comfort, temperatures, air humidity and air velocities were measured. Human body was considered as one complete piece composed of core and skin compartments and the Transient Energy Balance Model developed by Gagge et al. in 1971 was used to calculate changes in thermal parameters between passenger bodies and bus interior environment. Depending on the given initial and environmental conditions, the graphs of passengers Thermal Sensation and Thermal Discomfort Level were found. At the end, a general mathematical model supported with a related experimental procedure was developed for the use of automotive HVAC engineers and scientists working on thermal comfort as a human dimension. [ABSTRACT FROM AUTHOR]

Atmospheric particles (total suspended particles (TSPs); particulate matter (PM) with particle size below 10 μm, PM10; particulate matter with particle size below 2.5 μm, PM2.5) were collected and analyzed during heating and non-heating periods in Harbin. The sources of PM10 and PM2.5 were identified by the chemical mass balance (CMB) receptor model. Results indicated that PM2.5/TSP was the most prevalent and PM2.5 was the main component of PM10, while the presence of PM10-100 was relatively weak. SO42− and NO3− concentrations were more significant than other ions during the heating period. As compared with the non-heating period, Mn, Ni, Pb, S, Si, Ti, Zn, As, Ba, Cd, Cr, Fe and K were relatively higher during the heating period. In particular, Mn, Ni, S, Si, Ti, Zn and As in PM2.5 were obviously higher during the heating period. Organic carbon (OC) in the heating period was 2-5 times higher than in the non-heating period. Elemental carbon (EC) did not change much. OC/EC ratios were 8-11 during the heating period, which was much higher than in other Chinese cities (OC/EC: 4-6). Results from the CMB indicated that 11 pollution sources were identified, of which traffic, coal combustion, secondary sulfate, secondary nitrate, and secondary organic carbon made the greatest contribution. Before the heating period, dust and petrochemical industry made a larger contribution. In the heating period, coal combustion and secondary sulfate were higher. After the heating period, dust and petrochemical industry were higher. Some hazardous components in PM2.5 were higher than in PM10, because PM2.5 has a higher ability to absorb toxic substances. Thus PM2.5 pollution is more significant regarding human health effects in the heating period. [ABSTRACT FROM AUTHOR]

Using the daily electric power load and meteorological data over the period from January 2006 to September 2010 in Beijing, the general features of the electric power load and the main factors affecting this load have been analysed. The results indicate that winter and summer are the two peak power consumption seasons in each year. This finding could be mainly attributed to the consumption of energy for urban residential cooling or heating. In the summer, the daily minimum temperature was most closely correlated with the maximum power load (correlation co-efficient of 0.65, significant at the 0.1% level); the primary effect of temperature on the maximum power load varied largely from 376 to 858 MW °C −1, and it increased sharply when the daily minimum temperature was higher than 24 °C or the daily maximum temperature was higher than 32 °C. In the winter, the daily maximum temperature was most closely correlated with the power load (−0.45, 0.1% significance), and the primary effect varied from 109 to 391 MW °C −1. However, the relationship between the power load and the temperature was more complicated in the winter: this relationship varied during the central heating period and its pre- and post-periods. Moreover, the temperature humidity index (THI) could explain more of the variance in the daily maximum power load than any single temperature factor in the summer, while the wind-chill temperature index (WCT) did not contribute to this variance in the winter. Finally, due to the rapid urbanization of Beijing, the power load and the priamry effect increased each year. Copyright © 2012 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

A comprehensive measurement program was undertaken in winter 2009 in a large urban city (Ji'nan) in North China Plain (NCP). The average concentrations of NO, NO2, NOx, NOy, SO2, O3, CO, PM2.5 and BC during the program were 63.9±65.1ppb, 45.2±16.9ppb, 106.6±77.8ppb, 120.7±77.4ppb, 54.3±25.8ppb, 6.3±6.0ppb, 2138.3±1512.8ppb, 171.3±83.9μg/m3 and 9.8±6.9μg/m3, respectively. Two severe haze episodes were observed. All species, except O3, had elevated concentrations on the episodes compared with those on non-hazy days due to accumulation of pollutants. Diurnal variations of species concentrations and correlation analysis suggested that emissions from vehicles and coal combustion (from power plants, industry and domestic heating) are the main sources. Air mass on Episode 1 was predominately influenced by coal combustion, while pollution was characterized by the vehicular emissions on Episode 2. In contrast, on non-hazy days, pollutants were mainly from the mixing of local coal-fired and vehicular exhaust emissions. These distinct characteristics were further supported by higher ratios of CO to NOy and SO2 to NOy on Episode 1 (25.46ppb/ppb and 0.51ppb/ppb) compared to Episode 2 (15.55ppb/ppb and 0.36ppb/ppb) and non-hazy days (18.15ppb/ppb and 0.45ppb/ppb). Multiple linear regression analysis was applied to the concentrations of NOy, SO2 and CO in the observation and empirical equations were obtained for the NOy concentration. Based on the equations, the relative contributions from mobile (i.e. vehicular exhaust) and point sources (i.e. coal combustion) to NOy were estimated to be 68.2% and 38.6%, respectively, demonstrating that even in the demanding period of domestic heating in NCP, vehicular emissions in a large urban city contribute more to NOy than coal combustion emissions. This also implies that vehicular emissions, featured with high NOx, become a dominant source of pollution, highlighting the recent finding of long-term increase of NO2 in the NCP region by satellite observation (Richter et al., 2005). [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the transient effects of heater on temperature and humidity in an automobile cabin under transient heating period. Interior volume of an automobile is relatively small to other indoor environments, so that temperature and humidity values can rapidly change under highly transient conditions. Studies that are investigating the effects of heater on automobile cabin environment in real car conditions are restricted. Experiments were carried out in a parked car inside a laboratory at nights to prevent the possible wind and solar irradiation effects. In the experiments only plane vents were operated with three different air velocity levels. Temperature and relative humidity differences between air velocity levels were obtained, relations between time, temperature and relative humidity were calculated. From this study it is understood that temperature and relative humidity values inside a car vary directly from air velocity values. The obtained results can be used to improve other thermal comfort studies inside automobiles and also CFD analyses can be validated under transient conditions. [ABSTRACT FROM AUTHOR]

Abstract: Glucose reactions were conducted in hot compressed water (473–773K, 4–40MPa) by means of a batch-type reactor. The reactions in the heating period (about for 60s) were observed. More than 80% of the glucose was consumed in the heating period above 573K. Gasification of glucose was promoted with increasing temperature. The effect of heating rate (from 4.2 to 15.8K/s) on glucose conversion was also examined, and gasification of glucose was enhanced with increasing the heating rate. [Copyright &y& Elsevier]

Abstract: This paper describes a combined theoretical and experimental study of thermal comfort during the heating period inside an automobile. To investigate the effects of thermal conditions on the human physiology and thermal comfort during the heating period, temperature, humidity and air velocity were measured at a number of points inside the automobile, so thermal conditions were accurately determined. The human body was divided into 16 sedentary segments, and the change of temperature was observed both experimentally and theoretically. During transient conditions of the heating period, heat and mass transfer between the human body and the interior environment of an automobile were simulated by a computational model, and predictions were compared with the measured data. It is shown that there is a good agreement between the model predictions and experimental results. By means of the present model, the effects of the fast transient conditions of the heating period on the sensible and latent heat transfer from the body, body segments skin temperatures and thermal sensation were investigated in detail. [Copyright &y& Elsevier]

The gel strength of surimi made from Alaska pollock, common carp, grass carp, and silver carp was determined and compared for different incubation temperatures and periods. Gel strength and setting of the 3 freshwater fish species were inferior to that of Alaska pollock. Effects of the protein concentration, heating temperature and heating period on the gel strength were evaluated and compared utilizing the response surface methodology. Models for the breaking force and breaking distance of the surimi of the 4 species were established. Protein concentration was the major factor affecting the gel strength. Effects of heating temperature and heating period had differed somewhat among the surimi of the 4 species. [ABSTRACT FROM AUTHOR]

Secondary atmospheric pollutants are an important component of the particles found in Urumqi city, China, Further, secondary inorganic aerosols, in particular, increase significantly during the winter heating period. In this study, samples collected from October 2017 to August 2018 from Urumqi were analyzed. Results showed that the average concentration of water-soluble inorganic ions (WSIs) in the heating period (86.9 ± 31.1 μg·m−3) was significantly higher than that in the non-heating period (14.1 ± 8.67 μg·m−3). SNA (SO 4 2−, NO 3 −, NH 4 +) accounted for 90.7% of the total WSIs (TWSIs) in the heating period. Simulations revealed that the in situ pH (3.1) was higher in the heating period than that in non-heating period (0.66) when they were calculated by the aerosol thermodynamic model. The particles were found to be acidity during the entire period. The liquid water content of the particulates (LWC) was found to higher in the heating period (55.5 ± 51.8 μg·m−3) than the non-heating period (21.3 ± 40.3 μg·m−3). The average nitrogen oxidation rate (NOR) and sulfur oxidation rate (SOR) were 0.16 and 0.36, respectively, indicating a significant secondary formation of nitrate and sulfate in the atmosphere of Urumqi. Further analysis indicated that sulfate was significantly affected by the LWC and acidity of the particulates; nitrate was produced under ammonia-rich conditions in Urumqi, and the LWC facilitated the production of nitrate. This study provides information about the formation of secondary sulfate and nitrate aerosols during different periods in suburban Urumqi. • During the heating period, high concentrations of SO 4 2− and NO 3 − cannot lead to increase of the acidity of aerosols. • More crustal sources will affect the calculation results of the aerosol thermodynamic model. • Particulate liquid water plays a key role in formation of secondary aerosols in heating period. [ABSTRACT FROM AUTHOR]

In the context of the mismatch between the potential in biomass energy and energy demand, proper space allocation and energy flow are necessary to improve the utilization rate of biomass energy, but the spatial distribution of heating demand has not been fully studied. This paper takes 50 cities/counties in the UTC+0800 time zone of the centralized winter heating zone in China and investigates the effects of geographical latitude on the per-capita raw material consumption by biomass combined heat and power plants (biomass CHP plants). Per-capita energy consumption is determined by electricity and heating consumption. The per-capita raw material consumption by biomass CHP plants during heating and non-heating periods is calculated by combining the average calorific value of each province with thermal efficiency. A regression model was constructed for latitude and per-capita raw material consumption by biomass CHP plants. The resulting curve exhibited an inverse S-shape during the heating period, with a positive correlation, but an insignificant correlation during the non-heating period. The study area can be divided into a high-impact area (regions to the south of 37°N and north of 45°N) and a low-impact area (regions between 37°N and 45°N). The initial investment process for the high-impact area should use scale and the heat-to-power ratio for planning biomass CHP plants according to geographical area and the design energy flow based on latitude to improve the self-sufficiency and energy efficiency of the area. Image 1 • Latitude can affect material consumption of biomass combined heat and power plants. • Per capita heating consumption has strong latitude correlation. • Per capita electricity consumption does not show clear latitude dependence. • Shorten some cities' heating period can reduce energy waste without lowing standard. [ABSTRACT FROM AUTHOR]

To explore the impact of the "Coal to Gas" project on air pollution around Beijing, the pollution observation data during the heating periods (from Nov.15 to Mar.15) of 2017 and 2018 at Xianghe Observatory in Langfang, Hebei Province of China, were analyzed in combination with meteorological data and fuel incremental statistics. According to this project, Xianghe County reduced coal consumption and increased gas consumption by 26.71 million cubic meters in 2018. Our observations showed that some of the air pollutants in the Langfang area were effectively improved by changing fuel from coal to natural gas, including SO 2 , PM 2.5 , PM 10 and CO; the average concentrations of them in the heating period of 2018 significantly dropped compared with those in 2017, with decreases of 46.5%, 13.1%, 21.0% and 10.5%, respectively. However, the concentration of nitrogen oxides (NO X = NO+NO 2) increased significantly. The average NO X concentration increased from 78.7 to 116.1 μg/m3, while the concentrations of NO 2 and NO increased by 24.8% and 76.8%, respectively. Such a significant increase in NO X will bring about changes in the atmospheric oxidation process and influence human health. Changes in meteorological elements were not the main cause of elevated NO X because the total averaged PLAM changing rate and the PLAM changing rates in most of the months indicated a more favorable condition for the diffusion of pollutants. Through the comparison of daily changes in various pollutants during holidays and working days, the impact of motor vehicle emissions on the increase in NO X was essentially ruled out. Compared with that in the heating period of 2017, the significantly higher NO X in 2018 mainly appeared in early morning, which was consistent with the main heating period, and the differences in NO X between holidays and working days were found to be related to sectional heating. At the same time, it was found that the average concentration of NO 2 from Nov. 2018 to Mar. 2019 increased in all 12 cities in the Beijing-Tianjin-Hebei region compared with the same period of the previous year, and more than half of the cities had similar variation characteristics of NO 2 than that of Langfang. Heating gas was the main factor causing the increase in NO X concentration in Langfang city during the heating period in 2018. Excluding the impact of meteorological conditions, the "Coal to Gas" project brought about 51.8% increase in NO X in the southeast area of Beijing during the heating period of 2018, as well as 8.8%, 16.7%, 42.2% and 10.5% decrease of PM 2.5 , PM 10 , SO 2 and CO, respectively. Unlabelled Image • We explored the impact of the "Coal to Gas" project on NO X around Beijing for the first time. • Sharply rise of NO X in Xianghe was spotted in 2018 heating period, while PM 2.5 , SO 2 and CO decreased. • Higher NO X appeared in the main heating period in early morning. • The discrepancies of NO X between holidays and working were related to sectional heating. • The project triggered 51.8% increase in NO X in Langfang, but PM 2.5 , SO 2 and CO decreased 8.8%, 42.2% and 10.5%, separately. [ABSTRACT FROM AUTHOR]