Heating Requirements Research Articles

ABA and Not Chilling Reduces Heat Requirement to Force Cherry Blossom after Endodormancy Release.

Models used to predict the onset of fruit tree blossom under changed climate conditions should be physiologically based as much as possible. Pure optimized phenology models carry the risk of unrealistic predictions due to a misinterpretation of metabolic processes. This was the motivation determining the relevant phases for chill and heat accumulation, which induces cherry blossom (cv. Summit). Investigations are based on 8 years of observational and analytical data, as well as on controlled experiments. For ‘Summit’ buds, to be released from endodormancy, 43 chill portions from 1 September are necessary. After endodormancy release (t1), on average on 30 November, no further chilling is required, because no correlation between chill accumulation during ecodormancy and the subsequent heat accumulation until ‘Summit’ blossom exist. The declining amount of heat, which induces cherry blossom after t1—shown in several forcing experiments—seems to be the result of the declining bud’s abscisic acid (ABA) content, up to ~50% until the beginning of ontogenetic development. Shortly after t1, when the bud’s ABA content is high, a huge amount of heat is necessary to induce cherry blossom under controlled conditions. Heat requirement reduces during ecodormancy along with the reduction in the ABA content. According to these findings, plant development during ecodormancy is suppressed by low temperatures in the orchard and a slowly declining bud’s ABA content. These results should lead to a better consideration of the ecodormancy phase in phenology models.

Risk of Extreme Early Frosts in Almond

In almond, late frost is the main factor determining the viability of the culture in cold areas, and late flowering remains the key factor in addressing this issue. Climate change is causing an increase in the frequency of extreme weather events. In 2021, the cold period in Spain after the Filomena storm (11–14 January), in which temperatures reached −20 °C in some regions, was a clear expression in this regard. In many almond-growing areas, these low temperatures affected the closed flower buds of most of the cultivars, except for the extra-late and ultra-late cultivars and despite the early stage of development of the buds, leading crop failure. In this work, we show that early extreme frost only affected the extra-early, early and late almond cultivars that had overcome their endodormancy and fulfilled 40%, 31% and 23% of their heat requirements for flowering. Extra-late (with only 2% of their heat requirements covered) and ultra-late (still in endodormancy) cultivars were not damaged. These results show the importance of cultivating extra- and ultra-late almond flowering cultivars to avoid not only the late frost but also the early frost during the very early development of the flower buds.

Climate Change and Fuel Wood Energy Use in Cold Desert of Drass in the Himalaya, India

This paper has identified the impacts of climate change on fuel wood energy use in Drass, District Kargil, Ladakh in the Himalayan region and drawn the policy implication to improve the livelihoods of the people in the context of climate change using a case study approach. The study reveals that the major source of energy used and consumed in Drass is fuel wood. Almost all energy requirements for cooking and heating are met by burning fuel wood which produces smoke, cause air pollution, emits carbon dioxide and thereby contributes to climate change. Less than half of the farmers grow fuel wood in gardens or homesteads. Most farmers purchased fuel wood from the market. Awareness of environmental effects of using fuel wood is significant. Despite this, the exposure of women to indoor air pollution from biomass fuel combustion was significantly high. The use of cleaner energy was significantly low due to economic reasons as well as inadequate accessibility and availability. Forest resources are meager in Drass. Therefore, efforts should be made to increase forest cover with the stronger participation of local communities. The government sponsored schemes targeting efficient energy usage and energy insecurity should be implemented in letter and spirit through greater people's participation.

Study on Heating and Cooling Performance of Air-to-Water Heat Pump System for Protected Horticulture

There is much interest in alternative energy sources for greenhouse heating and cooling, due to the impact of severe climatic conditions and increasing fossil fuel prices. The main objective of this study was to experimentally evaluate the performance of an air-to-water heat pump (AWHP) system to fulfil the cooling and heating energy requirements of a three-spanned greenhouse under local weather conditions in Daegu, South Korea. For this purpose, a system comprising three air-to-water heat pumps, a water storage tank, and fan coil units (FCU)s was designed. Experiments were conducted extensively during the summer and winter seasons. The maximum heating and cooling energy supply to the greenhouse was 210 kcal∙h−1∙m−2 and 230 kcal∙h−1∙m−2, respectively. Based on the outcomes of this study, the AWHP system can provide heating during the winter season. During the summer season, the FCU capacity was insufficient to provide the desired cooling to achieve the setpoint air temperature inside the studied greenhouse. To achieve the desired microclimate during the summer season, the capacity of the FCU or number of FCUs must be increased. Moreover, one AWHP with a water storage tank, was sufficient to provide the required cooling and heating in both seasons. Two additional AWHPs can be used to provide energy to more greenhouse areas in the future. The results can be used as a case study to find a more resilient and reliable source for greenhouse heating and cooling. The average COP of the AWHP in heating mode was 2.2, while on cooling mode, it was 3.2.

Modeling the effect of adaptation to future climate change on spring phenological trend of European beech (Fagus sylvatica L.)

Temperate trees could cope with climate change through phenotypic plasticity of phenological key events or adaptation in situ via selection on genetic variation. However, the relative contribution of local adaptation and phenotypic plasticity to phenological change is unclear for many ecologically important tree species. Here, we analyzed the leaf-out data of European beech (Fagus sylvatica L.) from 50 provenances planted in 7 trial sites. We first constructed a function between chilling accumulation (CA) and photoperiod-associated heat requirement (PHR) of leaf-out date for each provenance and quantified the relationship between parameters of the CA-PHR function and climatic variables at provenance origins by using the random forest model. Furthermore, we used the provenance-specific CA-PHR function to simulate future leaf-out dates under two climate change scenarios (RCP 4.5 and 8.5) and two assumptions (no adaptation and adaptation). The results showed that both CA, provenance, and their interactions affected the PHR of leaf-out. The provenances from southeastern Europe exhibited a stronger response of PHR to CA and thus flushed earlier than northwestern provenances. The parameters of the CA-PHR function were connected with climatic variables (e.g., mean diurnal temperature range, temperature seasonality) at the originating sites of each provenance. If only considering the phenotypic plasticity, the leaf-out date of European beech in 2070–2099 will advance by 6.8 and 9.0 days on average relative to 1951–2020 under RCP 4.5 and RCP 8.5, respectively. However, if F. sylvatica adapts to future climate change by adopting the current strategy, the advance of the leaf-out date will weaken by 1.4 and 3.4 days under RCP 4.5 and RCP 8.5, respectively. Our results suggest that the European beech could slow down its spring phenological advances and reduce its spring frost risk if it adopts the current strategy to adapt to future climate change.

Anoxic desulphurisation of biogas from full-scale anaerobic digesters in suspended biomass bioreactors valorising previously nitrified digestate centrate

Nitrification of centrate from anaerobic sewage sludge digestion presents a major opportunity as an electron acceptor in anoxic biogas biodesulphurisation. Nitritation and nitrification inhibition by free ammonia was detected at laboratory scale, but was avoided during the scale-up operation in a 4 m3 reactor treating ammonium loads up to 19 gN m−3 h−1. This nitrate-rich stream was fed to two pilot-scale suspended biomass bioreactors (SBBs) treating real biogas for 220 days. After an adaptation period of 21 days, nitrate and alkalinity concentrations in the liquid medium below 10 mgN L−1 and 100 mgCaCO3 L−1 were found to limit hydrogen sulphide (H2S) oxidation. Once controlled, 95% of the H2S was removed in SBB1 and 90% in SBB2, at a gas residence time (GRT) of 5.9 min, treating average values of 321 ± 205 ppmv and 457 ± 205 ppmv, respectively. Outlet H2S concentrations of 16 ± 24 ppmv in SBB1 and 46 ± 39 ppmv in SBB2 were obtained, which are below the requirements of biogas combustion heat and power engines. Unlike H2S, siloxanes were not removed with these GRTs. The results demonstrate the feasibility of the combined process for H2S treatment, potential valorisation of precipitated elemental sulphur and a reduction in the reagents currently used to control H2S.

Continuous co-generation of biohydrogen and biomethane through two-stage anaerobic digestion of hydrothermally pretreated food waste

Increasing accumulation of food waste (FW) exerts pressure on resource conservation and environmental protection, while conventional anaerobic digestion (AD) of raw FW for bioenergy recovery and waste minimization often encounters limitations such as fast acidification and process failure. Herein, mild hydrothermal pretreatment (HTP: 140 °C, 20 min) of raw FW was employed to advance subsequent AD performances in a long-term continuous mode. With a decreased overall hydraulic retention time (HRT) from 30 to 18 days, the two-stage system digesting HTP-treated FW maintained very stable and robust biohydrogen (38.1 mL/gVS) and biomethane (439.6 mL/gVS) co-production, whereas both the two-stage system digesting raw FW and the one-stage system digesting HTP-treated FW exhibited deteriorating trends with significantly lower energy yields by 61.1% and 28.1%, respectively. Microbial community analyses revealed the less involvement of carbohydrate-fermenting and proteolytic microbes in the second-stage biomethane reactors as a result of the enhanced hydrolysis and acidogenesis of FW through HTP and first-stage biohydrogen fermentation. A proximate energy balance assessment indicated that the energy gain of increased biogas generation offset the extra heat requirement for the HTP of FW, while a significant treatment capacity enhancement of 66.7% was achieved given the HRT reduction from 30 to 18 days through this integrated system.

Flexibility System for Heilongjiang Power Grid Considering Carbon Reduction Targets

Enhancing the flexibility of power systems helps to balance the increasing renewable generation for achieving the rigid carbon reduction targets. The current flexible system in China can hardly meet the regulating demand of its ever-increasing renewable generation, especially in the Heilongjiang power grid (HPG), where the proportion of combined heat and power units that determine power generation by the heat requirement is enormous, while the peak shaving capacity in winter is limited. This research analyzes the necessity of establishing a new flexibility system for the HPG. Also, it introduces the new characteristics and the flexibility of the HPG. Then, it proposes classification and definition methods for the flexibility system of the HPG by referring to some similar power grids, e.g., the UK grid and the Danish grid. A simulation framework of power systems with flexibility enhancement is developed to perform quantitative evaluation of the HPG in different carbon reduction scenarios. The suggested flexibility system reorganizes and revises the principles of reserve classification, response time, and minimum reserve configuration. Simulation results verify the effectiveness of the proposed method through the measurement and analysis data of the HPG. This paper takes the HPG as an example to perform a quantitative analysis of the flexibility system. Also, it can provide tips and suggestions for other regions seeking carbon reductions.

CO2 regeneration energy requirement of carbon capture process with an enhanced waste heat recovery from stripped gas by advanced transport membrane condenser

This study proposed to build an energy efficient and reliable CO2 regeneration system, via the integration of an advanced transport membrane condenser (TMC) and principle of rich solvent-split (RS), namely the TMC-based RS system. With the monoethanolamine (MEA) solvent and a TMC module housed commercial 19-channel hydrophilic ceramic membranes, the operational stability and energy requirement of the proposed system were evaluated. With a relatively low error (i.e., ± 5%) of the overall mass balance, the proposed system exhibited excellent reliability in operation. Compared to the traditional CO2 regeneration process without the RS modification, the conventional system with only the RS modification showed 4.8% saving in the reboiler duty (kWh/kg-CO2) at the split fraction of 10%; while the TMC-based RS process showed up to 21.7% saving in the reboiler duty with 0.2 m2 membrane area at the split fraction of 30%. The energy saving corresponded to a decrease from 5.2 MJ/kg-CO2 to 3.9 MJ/kg-CO2 in terms of the calculated CO2 regeneration heat requirement. The sensitivity analysis showed that the TMC-based RS system was less susceptible to variations in operation conditions, demonstrating a low and relatively stable reboiler duty. An additional benefit of the proposed system was the reduced consumption of cooling water.

Modeling Electrokinetics of Oxygen Electrodes in Solid Oxide Electrolyzer Cells

High temperature solid oxide electrolyzers operated at >600oC are advantageous from a thermodynamic perspective since heat (TDS) can be converted into chemical energy (DH) [1]. This additional heat reduces the overall electrical power (DG) requirement, allowing an electrolysis cell to achieve ~100% efficient H2 production [1]. Since the thermal energy contribution to the electrolysis reaction can also be obtained from sensible Joule heating produced within the cell, the electrical energy demand is further reduced which decreases the H2 production price. The bulk of the heat can be provided by an external source such as nuclear power, solar thermal power, or waste heat from a chemical plant. Theoretically, there is no external heat requirement if the electrolyzers operate at the thermoneutral voltage. Due to the above advantages, the research and development on solid oxide-based water electrolyzers have received significant attention [1–6].This work focuses on physics-based modeling of high temperature solid oxide electrolysis cells (SOEC). A microscale model is presented to simulate electrode kinetics of the oxygen electrode in a solid oxide electrolyzer cell (SOEC). Two mixed ionic/electronic conducting structures are examined for the oxygen producing electrode in this work: single layer porous lanthanum strontium cobalt ferrite (LSCF), and bilayer LSCF/SCT (strontium cobalt tantalum oxide) structures. An yttrium-stabilized zirconia (YSZ) electrolyte separates the hydrogen and oxygen electrodes, as well as a gadolinium doped-ceria (GDC) buffer layer on the oxygen electrode side. Electrochemical reactions [7-8] occurring at the two-phase boundaries (2PBs) and three-phase boundaries (3PBs) of single-layer LSCF and bilayer LSCF/SCT oxygen electrodes are modeled under various SOEC voltages with lattice oxygen stoichiometry as the key output. The results reveal that there exists a competition in electrode kinetics between 2PBs and 3PBs, but 3PBs are the primary reactive sites for single-layer LSCF oxygen electrode under high voltages. These locations experience the greatest oxygen stoichiometry variations and are therefore the most likely locations for dimensional changes. By applying an active SCT layer over LSCF, the 2PBs become activated to compete with the 3PBs, thus alleviating oxygen stoichiometry variations and reducing the likelihood of dimensional change. This strategy could reduce lattice structural expansion, proving to be valuable for electrode-electrolyte delamination prevention and will be the focus of future work. Figure 1

Recent Studies on the Environmentally Benign Alkaline-Earth Silicide Mg2Si for Middle-Temperature Thermoelectric Applications

Most primary energy sources, such as the fossil fuels of oil, coal, and natural gas, produce waste heat. Recycling of this unused thermal energy is necessary in order to increase the efficiency of usage. Thermoelectric (TE) conversion technologies, by which waste heat is directly converted into electricity, have been extensively studied, and the development of these technologies has continued. TE power-generation has attracted significant attention for use in self-powered wireless sensors, which are important for our increasingly sophisticated information society. For the middle-temperature range (i.e., 600–900 K), with applications such as automobiles, intensive studies of high-performance TE materials have been conducted. In this study, we review our recent experimental and theoretical studies on alkaline-earth silicide Mg2Si TE materials, which consist of nontoxic abundant earth elements. We demonstrate improvements in TE performance brought about by lightly doping Mg2Si with isoelectronic impurities. Furthermore, we examine the electrode formation and material coatings. Finally, we simulate the exhaust heat requirements for the practical application of TE generators.

Design of trigeneration plant for electricity freshwater production, and district heating: A case study Periwinkle Lifestyle Estate, Lagos Nigeria

This study proposes a design of a trigeneration plant for the usage of Periwinkle Lifestyle Estate in Lagos State Nigeria. The proposed system would provide electricity, heating and freshwater requirements for residential buildings from a renewable energy source. Concentrated photovoltaic solar thermal (CPV/T) collector is used to generate the electricity and provides the required amount of thermal energy to the multistage flash desalination plant and Kalina cycle due to its high electrical and thermal effectiveness. The EES is used to model the tri-generation system by solving the governing equations with an interconnected structure, while TRNSYS and HOMER software was also used to collect the solar data for the case study area. The combined trigeneration structure can produce 0.6412 kg/s of freshwater, 1520.25 kW of electricity generation, and 91.57 kW of heat required for the district heating application, for the usage of Periwinkle lifestyle estate Lagos State Nigeria. The designed system can serve as an alternative to producing high-quality freshwater for drinking and irrigation, reliable and steady electricity and heating services during the winter season, without pollution. • A trigeneration system using CPVT is presented. • The effect of ammonia concentration on the system is analyzed. • The combined trigeneration structure can produce 0.6412 kg/s of freshwater, 1520.25 kW of electricity generation. • The proposed system can meet the electricity, heating and fresh water demands of case study city.

Adsorption, separation and regeneration of cation-exchanged X zeolites for LNG purification: Li+, K+, Mg2+ and Ca2+

The Li+, K+, Mg2+ and Ca2+-exchanged X zeolites were prepared using ion exchange method for producing efficient adsorbents that could be used in the purification of liquefied natural gas (LNG). The adsorption, separation and regeneration characteristics of the samples were systematically explored and discussed using static adsorption of pure gases, dynamic adsorption of a binary gas mixture (3%CO2 and 97%CH4) and regeneration experiments. The results showed that Li13X had the largest surface area of 520 m2/g, whereas Ca13X possessed the highest micropore volume of 0.25 m3/g with the smaller pore size observed from the pore size distribution. The adsorption capacity of Li13X for CO2 (4.10 mmol/g) was almost the same as that of Ca13X (4.12 mmol/g), which were larger than all the other samples at 120 kPa and 30 °C. However, K13X had the highest static CO2/CH4 separation factor of 46, which was due to the increased basicity of the framework. For the dynamic adsorption, Ca13X possessed the highest CO2/CH4 separation factor of 93, and showed the smallest CH4 adsorption capacity of 1.22 mmol/g. As for the regeneration of the proposed adsorbents, the heat requirement for CO2 in dynamic was not only affected by the isosteric heat, but was also dependent on the competition between CH4 and CO2. Moreover, the static and dynamic vacuum regenerations had the same tendency and mainly depended on the pore size distribution.

Synthesis of ZnO nanoparticles at room temperature with enhanced ultra‐violet photoluminescence

ZnO nanoparticles (NPs) have attracted a lot of attention due to the possibility of their applications in different fields including optoelectronics, photonics, biosensing, catalytic, etc. Most of the applications require devices made of good quality of NPs. However, synthesis of device grade NPs is always challenging. Here, improvement of crystalline quality of the ZnO NPs has been demonstrated with a very simple procedure. ZnO NPs of average crystallite size of ~11.5 nm with optical band gap of ~3.44 eV have been synthesized in room temperature following the co-precipitation method by either varying the concentration of KOH or time of synthesis. For both the cases, change in average size of NPs has not been found to change significantly. This is mainly because the required heat energy to grow the size has not been provided externally. However, the increase of concentration of KOH or time of preparation has been found to improve the quality of the ZnO crystallites. The improvement of crystalline quality has been argued as due to the availability of enough KOH or the time to repair the defects on the surface of the NPs. Improvement of crystalline quality has been found to result in an enhancement of intensity of the ultraviolet (UV) photoluminescence (PL) emission band over the visible PL emission band of ZnO. The defect mediated visible PL emission is always considered as loss. The enhancement is ~2-fold. Such large enhancement can be utilized for the fabrication of optoelectronic devices and others based on ZnO NPs synthesized at room temperature.

Negative Emission Power Plants: Thermodynamic Modeling and Evaluation of a Biomass-Based Integrated Gasification Solid Oxide Fuel Cell/Gas Turbine System for Power, Heat, and Biochar Co-Production—Part 1

This article is the first of a two-part series presenting the thermodynamic evaluation and techno-economics of developing negative-emission power plants. The aim of this research is to evaluate the potential of biochar co-production in negative-emission power plants based on biomass-fed integrated gasification solid oxide fuel cell systems with carbon capture and storage (BIGFC/CCS) units. The influence of two gasification agents, namely, air and steam-oxygen, on the proposed system is investigated. In Part I, we present the thermodynamic models. A sensitivity analysis is carried out to investigate the system response to stepwise increase in biochar co-production (up to 10% by weight). Providing a secondary oxy-combustor in the steam-oxygen gasification case has been shown to be a solution to meet the heat requirements of the allothermal gasification process. A comprehensive exergy analysis indicated significant efficiency improvement for the steam-oxygen gasification case. The results show that the biomass steam-oxygen gasification yields the higher electrical exergy efficiency (48.3%) and combined heat and power (CHP) exergy efficiency (54.6%) for the similar rates of biochar co-production. The specific power output per unit of CO2 stored is 2.65 MW/(kg/s) and 3.58 MW/(kg/s) for the air and steam-oxygen gasification cases, respectively, when the biochar is co-produced at 10% by weight for the given biomass flow of 20 kg/s. Moreover, the total CO2 stored due to the proposed system is calculated as 133.9 t/h, and it is estimated to remove 1.17 Mt of CO2 from the atmosphere annually (when the biochar-based carbon storage is also considered). The models are used for the techno-economic analysis presented in Part II of the series.

Energetics of Technical Integration of 2‐Propanol Fuel Cells: Thermodynamic and Current and Future Technical Feasibility

2‐Propanol/acetone is a promising liquid organic hydrogen carrier system for fuel cell reactions. Herein, six different concepts for a 2‐propanol/acetone fuel cell system are evaluated in MATLAB simulation with respect to their thermodynamic integration and technical feasibility. Four of the concepts use a direct 2‐propanol fuel cell while the other two first release molecular hydrogen from 2‐propanol and subsequently use a hydrogen fuel cell. The presented liquid phase 2‐propanol fuel cell concept is thermodynamically feasible but cannot be realized technically using commercial Nafion membranes, due to membrane dissolution by the 2‐propanol/acetone/water fuel mixture. Gaseous 2‐propanol fuel cells imply a high heating requirement for the evaporation of the fuel. A direct high‐temperature fuel cell using 2‐propanol is thermodynamically feasible because there is less water in the overall system but is not technically feasible because of the esterification of phosphoric acid. A very interesting option is the conversion of gaseous 2‐propanol to pressurized hydrogen in an electrochemical pumping step followed by a hydrogen fuel cell, because here the waste heat of a sufficiently hot hydrogen fuel cell can drive the 2‐propanol evaporation.

Climate change and viability of fruit tree orchards in arid area

The Mediterranean region is facing temperature increases due to climate change. More warm conditions across the fruit and nut growing regions are expected to have a great and negative impact in Tunisian arid regions. Chilling trends among the agricultural production areas and their incidence on flowering and fruiting of typical fruit species were investigated. The results showed important declines in winter chill accumulation over the main arid production areas. This lack of chill jeopardizing the flowering and fruiting of fruit species. However, fruit species and cultivars within each fruit species expressed different flowering and fruiting behaviors to warm climate depending on their chilling and heat requirements. Consequently, thermal requirements are a key factor for sustainable fruit trees’ orchards and to select suitable cultivation area. Adoption of appropriate genetic resources could be used to mitigate the harmful effect of global warming in arid regions.

Economics of Implementing Solar Thermal Heating Systems in the Textile Industry

This paper analyzes the potential of solar thermal systems for being employed for process heating in cotton-based textile industries. The technological capability of a flat plate collector (FPC) to meet the solar industrial process heating (SIPH) requirement in yarn production is assessed. Moreover, the usability of a parabolic trough collector (PTC) in meeting the technological mandates of SIPH in fabric processing units is critically examined. Further, this paper reports the findings of a study on the potential cost advantage of solar process heating over the conventional process heating practices in cotton-based textile industries. The approach involves the selection of the locations of sample textile industries and the employable solar collector technologies, as well as assessment of financial reward, if any. Eight different cotton-based textile industries located in different geographical domains (in India) are selected. The selected textile industries are situated within the textile hubs existing in different states across India. Analysis of technoeconomic benefit derivable in selected textile industries using FPC for hot water generation and PTC for steam generation is presented. In the case of FPC-based SIPH systems, the maximum value of solar fraction is estimated to be 0.30 and the corresponding estimation for the levelized cost of useful thermal energy (LCUTE) delivered comes out as INR 790/GJ to INR 1020/GJ. On the other hand, in case of parabolic-trough-solar-concentrator-based SIPH systems, LCUTE is estimated in the range of INR 1030/GJ to INR 1610/GJ. From a critical analysis of financial viability in consideration of related factors such as payback time and return on investment in SIPH, it appears that the SIPH systems for hot water generation may be a good choice, whereas SIPH systems for steam generation are seen to have longer payback periods and lower returns on investment, and, therefore, it seems that adequate financial support from central and state governments with additional supports from bilateral or multilateral organizations may enable them to become a sustainable technology option.

UV coated acrylics as a substitute for generic glazing in buildings of Indian climatic conditions: Prospective for energy savings, CO2 abatement, and visual acceptability

The generic clear glass used in the existing buildings has the limitations such as high heat gain/loss, glare, and poor thermal performance. Substitution for the existing building conventional glazing systems should be given full consideration in sustainable development due to its significant impact on energy consumption and greenhouse gas (GHG) emissions. The study explores various UV-coated acrylics as a substitute for generic clear glass. Thermo-optical characterization was performed to calculate UV-coated acrylics' un-steady state thermal transmittance and solar-optical properties. A thermo-economic analysis of UV-coated acrylics was undertaken in a four-floor high glazed building in two different Indian climates (hot and temperate) to assess the reductions in heat gains, corresponding energy savings, and carbon emission mitigations. The findings revealed that UV-coated acrylics' heat gain/loss inside the buildings was reduced compared to the generic clear glass. Compared to generic clear glass, UV-coated acrylics reduced heat gain by 25.5% and 23.5% in hot and temperate climes, respectively. Reduced heat gains resulted in energy savings for cooling and heating requirements, resulting in annual cost savings of 8667 $/year for a temperate climate and 5974 $/year for a hot climate, respectively. Lower energy requirements for cooling and heating resulted in carbon reductions of 88.7 and 56.2 tCO2/year for temperate and hot climates, respectively. Energy Plus simulations have been used to validate the mathematical model results and evaluate daylight infiltration in buildings with UV-coated acrylics at various brightness levels. UV-coated acrylics' measured daylight ingress metrics and color rendering metrics ensure good visual acceptability in building interiors.

A methodology for evaluating the effects of climate change on climatic design conditions for buildings and application to a case study in Madison, Wisconsin

Abstract Climatic design conditions are widely used by the building community as environmental parameters informing the size and energy requirements for heating, ventilation and air conditioning systems, along with other building design characteristics. Climatic design conditions are calculated by the American Society of Heating, Refrigerating and Air-conditioning Engineers using historical climate data. Our work advances methods for projecting future climate design conditions based on data from global climate models. These models do not typically archive the hourly data required for climate design condition calculations, and they often exhibit large biases in extreme conditions, daily minimum temperatures and daily maximum temperatures needed for climatic design conditions. We present a method for rescaling historical hourly data under future climatic states to estimate the impact of climate change on future building climatic design conditions. This rescaling method is then used to calculate future climatic design conditions in Madison, Wisconsin, throughout the 21st century for two future greenhouse gas emissions scenarios. The results are consistent with a warming climate and show increases in heating, cooling, humidification and dehumidification design conditions, suggesting less extreme cold conditions and more extreme hot and humid conditions in Madison. The design conditions used for estimating energy demand, degree days, show that under a business-as-usual scenario, by the mid-century, building heating and cooling in Madison (climate zone 5A) will be similar to the current heating demand in Chicago, IL (climate zone 5A) and cooling demand in Baltimore, MD (climate zone 4A); by the late-century, building heating and cooling in Madison will resemble the current heating demand in St Louis, MO (climate zone 4A) and cooling demand in Augusta, GA (climate zone 3A). Given the rapid pace of climate change in the 21st century, our work suggests that historical design conditions may become obsolete during even the initial stages of a building’s expected life span. Changes in climatic design conditions in Madison highlight the importance of considering future climatic changes in building design to ensure that buildings built today meet the performance needs of the future.